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Apache Cassandra Connector 4.1 Examples - Mule 4

The following examples show how to configure Apache Cassandra Connector:

Create a New Apache Cassandra Table

This example contains the following flows:

  • The first flow configures a template for the HTML input form used to convey data for the new table.

  • The second flow creates the keyspace for the new table.

  • The third flow creates the new table.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

Configure a Template for the HTML Input Form

This flow configures an HTML template to use for providing HTML input to create the new table:

Parse Template Flow
Figure 1. Flow for configuring an HTML template

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / path on port 8081:

  1. Create a new Mule Project in Anypoint Studio.

  2. In Studio, click HTTP and drag the Listener operation to the canvas.

  3. On the Listener properties window, click the plus sign (+) next to the Connector configuration field to add a global element.

  4. Accept the defaults.

  5. On the Listener properties window, set the Path field value to /.

Add a Parse Template Component

Add a Parse Template component to create a template for an HTML form (form.html), which is located in the main resources folder. The example uses this form to convey information for creating the table.

  1. From the Mule Palette view, search for parse and drag Core > Parse Template to the right of Listener.

  2. In the Location field, enter form.html.

Create the Keyspace

This flow creates the keyspace for the new table:

Create keyspace flow
Figure 2. Flow for creating a keyspace

Configure HTTP listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the /test/createKeyspace path on port 8081:

  1. Create a new Mule Project in Anypoint Studio.

  2. In Studio, click HTTP and drag the Listener operation to the canvas.

  3. On the Listener properties window, click the plus sign + next to the Connector configuration field to add a global element.

  4. Accept the defaults.

  5. In Listener configuration window, set the Path field value to /test/createKeyspace.

Add a Transform Message Component

Add a Transform Message component to set Java variables based on the payload received from HTTP Listener:

  1. From the Mule Palette view, drag a Transform Message component to the right of Listener.

  2. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
     "keyspaceName": payload.keyspaceName,
     "replicationFactor": payload.replicationFactor,
     "replicationStrategyClass": payload.replicationStrategyClass
    }
    as Object {
     class: "org.mule.modules.cassandradb.api.CreateKeyspaceInput"
    }

Add the Create Keyspace Operation

Add the Create keyspace operation to create the keyspace where the new table will reside:

  1. From the Mule Palette view, select CassandDB and drag the Create keyspace operation to the right of the Transform Message component.

  2. In the Create keyspace configuration, click the plus sign (+) next to the Connector configuration field to add a global element.

  3. Configure the fields in the global element:

    Field Description

    Host

    ${cassandra.Host}

    Port

    ${cassandra.Port}

    Keyspace

    ${cassandra.keySpace}

    Username

    ${cassandra.userName}

    Password

    ${cassandra.password}

  4. Click Test Connection to confirm that Mule can connect with the target Apache Cassandra instance.

    If the connection is successful, click OK to save the configuration. Otherwise, review and correct any invalid parameters and retest.

  5. Save the project.

  6. Test the app by sending a REST request to the test/createKeyspace path on port 8081.

Create a New Table

This flow creates a new table in the target Apache Cassandra database:

Create table flow
Figure 3. Flow for creating a new table

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the /test/createTable path on port 8081:

  1. Create a new Mule Project in Studio.

  2. In Studio, click HTTP and drag the Listener operation to the canvas.

  3. In the Listener configuration, click the plus sign + next to the Connector configuration field to add a global element.

  4. Accept the defaults.

  5. In the Listener configuration, set the Path field value to /test/createTable.

Add a Transform Message Component

Add a Transform Component to set Java variables based on the payload received from HTTP Listener:

  1. From the Mule Palette view, drag a Transform Message component to the right of Listener.

  2. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "columns": payload.columns,
      "tableName": payload.tableName,
      "keyspaceName": payload.keyspaceName
    } as Object {
      class : "org.mule.modules.cassandradb.api.CreateTableInput"
    }

Add the Create Table Operation

Add a Create Table operation to create a new table in the keyspace you created in the previous flow:

  1. From the Mule Palette view, select CassandDB and drag the Create Table operation to the right of the Transform Message component.

  2. In the Create Table configuration, click the plus sign (+) next to the Connector configuration field.

  3. Select the global element that you configured for the Create keyspace operation.

  4. Click OK.

  5. Click Test Connection to confirm that Mule can connect with the Cassandra instance.

    If the client test is successful, click OK to save the configuration. Otherwise, review and correct any invalid parameters and retest.

  6. Save and run the Mule app.

  7. Test the app by sending a POST command to the /test/createTable path on port 8081. Use the application/json MIME type and enter the table description in the command body, using uppercase for the data types:

    {
      "tableName": "users",
      "keyspaceName": "Excelsior",
      "columns":
      [
        {
          "name": "id",
          "type": "INT",
          "primaryKey": "true"
        },
        {
          "name": "username",
          "type": "TEXT",
          "primaryKey": "true"
        },
        {
          "name": "name",
          "type": "TEXT",
          "primaryKey": "false"
        },
        {
          "name": "email",
          "type": "TEXT",
          "primaryKey": "false"
        }
      ]
    }

XML for the Create an Apache Cassandra Keyspace and Table Example

Paste this code into the Studio XML editor to quickly load the flow for this example into your Mule app:

<?xml version="1.0" encoding="UTF-8"?>

<mule xmlns:cassandra-db="http://www.mulesoft.org/schema/mule/cassandra-db"
xmlns:ee="http://www.mulesoft.org/schema/mule/ee/core"
xmlns:http="http://www.mulesoft.org/schema/mule/http"
xmlns="http://www.mulesoft.org/schema/mule/core"
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.mulesoft.org/schema/mule/core
http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http
http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/ee/core
http://www.mulesoft.org/schema/mule/ee/core/current/mule-ee.xsd
http://www.mulesoft.org/schema/mule/cassandra-db
http://www.mulesoft.org/schema/mule/cassandra-db/current/mule-cassandra-db.xsd">

  <configuration-properties file="mule-app.properties" />
  <http:listener-config name="HTTP_Listener_config" doc:name="HTTP Listener config">
    <http:listener-connection host="0.0.0.0" port="8081" />
    </http:listener-config>
  <cassandra-db:config name="CassandraDB_Config" doc:name="CassandraDB Config">
    <cassandra-db:connection
      host="${config.host}"
      port="${config.port}"
      keyspace="${config.keyspace}"
      username="${config.username}"
      password="${config.password}"/>
	</cassandra-db:config>
  <flow name="HTMLForm">
    <http:listener doc:name="Listener" config-ref="HTTP_Listener_config" path="/"/>
    <parse-template doc:name="Parse Template" location="form.html"/>
  </flow>
  <flow name="CreateKeyspace">
    <http:listener
      doc:name="Listener"
      config-ref="HTTP_Listener_config"
      path="/createKeyspace"/>
    <ee:transform doc:name="Transform Message">
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "keyspaceName": payload.keyspaceName,
  "replicationFactor": payload.replicationFactor,
  "replicationStrategyClass": payload.replicationStrategyClass
} as Object {
  class : "org.mule.modules.cassandradb.api.CreateKeyspaceInput"
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:create-keyspace doc:name="Create keyspace" config-ref="CassandraDB_Config"/>
    <ee:transform doc:name="Transform Message">
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="CreateTable">
    <http:listener doc:name="Listener" config-ref="HTTP_Listener_config" path="/createTable"/>
    <ee:transform doc:name="Transform Message">
      <ee:message>
        <ee:set-payload><![CDATA[%dw 2.0
output application/java
---
{
  "columns": payload.columns,
  "tableName": payload.tableName,
  "keyspaceName": payload.keyspaceName
} as Object {
  class : "org.mule.modules.cassandradb.api.CreateTableInput"
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:create-table doc:name="Create table" config-ref="CassandraDB_Config"/>
    <ee:transform doc:name="Transform Message">
      <ee:message>
        <ee:set-payload><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
</mule>

Manipulate Data in an Apache Cassandra Database

This example shows the following ways to manipulate data in an Apache Cassandra database:

Get Table Names from a Keyspace

This Mule flow returns all table names from the specified keyspace.

Studio flow for the Get table names from keyspace operation

In this flow, you configure:

  • An HTTP Listener component

  • A Get table names from keyspace operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /getTablesFromKeyspace.

Add the Get Table Names from Keyspace Operation

The Get table names from keyspace operation returns all table names from the specified keyspace.

  1. Drag the Get table names from keyspace operation onto the canvas, next to HTTP Listener.

  2. In the Get table names from keyspace configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Get table names from keyspace properties window:

    Field Value

    Keyspace name

    #[payload.keyspaceName]

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Get table names from keyspace.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Insert

This Mule flow inserts entities in a table in a keyspace.

Studio flow for the Insert Entity operation

In this flow, you configure:

  • An HTTP Listener component

  • A Transform Message component

  • An Insert Entity operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /insert.

Add the Transform Message Component

The Transform Message component converts the data from the keyspace to Java.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to HTTP Listener.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "id": payload.id,
      "name": payload.name,
      "event": payload.event
    }

Add the Insert Entity Operation

The Insert Entity operation inserts entities into a table in a keyspace.

  1. Drag the Insert Entity operation onto the canvas, next to Transform Message.

  2. In the Insert Entity configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Insert Entity properties window:

    Field Value

    Table

    example_table

    Keyspace name

    example_keyspace

    Entity to insert

    payload

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Insert Entity.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Select

This Mule flow executes a Select query.

Studio flow for the Select operation

In this flow, you configure:

  • An HTTP Listener component

  • A Select operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /insert.

Add the Select Operation

The Select operation executes a Select query on the keyspace.

  1. Drag the Select operation onto the canvas, next to HTTP Listener.

  2. In the Select configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Select properties window:

    Field Value

    Query

    SELECT id, name, event FROM example_keyspace.example_table

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Select.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Update

This Mule flow updates entities in a table in a keyspace.

Studio flow for the Update Entity operation

In this flow, you configure:

  • An HTTP Listener component

  • A Transform Message component

  • An Update Entity operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /update.

Add the Transform Message Component

The Transform Message component converts the data from the keyspace to Java.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to HTTP Listener.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "where":{
        id: payload.where
      },
      "columns":payload.columns
    }

Add the Update Entity Operation

The Update Entity operation inserts entities into a table in a keyspace.

  1. Drag the Update Entity operation onto the canvas, next to Transform Message.

  2. In the Update Entity configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Update Entity properties window:

    Field Value

    Table

    example_table

    Keyspace name

    example_keyspace

    Entity to insert

    payload

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Update Entity.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Delete

This Mule flow deletes a record from a table in a keyspace.

Studio flow for the Delete Rows operation

In this flow, you configure:

  • An HTTP Listener component

  • A Transform Message component

  • A Delete Rows operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /deleteRows.

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to HTTP Listener.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "where": {
        id: payload.ids
      }
    }

Add the Delete Rows Operation

The Delete Rows operation deletes a record.

  1. Drag the Delete Rows operation onto the canvas, next to Transform Message.

  2. In the Delete Rows configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Delete Rows properties window:

    Field Value

    Table

    example_table

    Keyspace name

    example_keyspace

    Entity to insert

    payload

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Delete Rows.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Delete Columns

This Mule flow deletes a column’s value from a table in a keyspace.

Studio flow for the Delete Columns Value operation

In this flow, you configure:

  • An HTTP Listener component

  • A Transform Message component

  • An Delete Columns Value operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /deleteColumns.

Add the Transform Message Component

The Transform Message component converts the data from the keyspace to Java.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to HTTP Listener.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "columns": payload.columns,
      "where": {
        id:payload.where
      }
    }

Add the Delete Columns Value Operation

The Delete Columns Value operation deletes values from an object specified by the Where clause field.

  1. Drag the Delete Columns Value operation onto the canvas, next to Transform Message.

  2. In the Delete Columns Value configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Delete Columns Value properties window:

    Field Value

    Table

    example_table

    Keyspace name

    example_keyspace

    Entities

    Edit inline

    Value

    #[payload.entities]

    Where clause

    payload

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Delete Columns Value.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Rename Columns

This Mule flow renames a column in a table in the specified keyspace.

Studio flow for the Rename Column operation

In this flow, you configure:

  • An HTTP Listener component

  • A Rename Column operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /renameColumn.

Add the Rename Column Operation

The Rename Column operation renames a column in a table in a keyspace.

  1. Drag the Rename Column operation onto the canvas, next to HTTP Listener.

  2. In the Rename Column configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Rename Column properties window:

    Field Value

    Table

    #[payload.tableName]

    Keyspace name

    #[payload.keyspaceName]

    Old column name

    payload.oldName

    New column name

    #[payload.newName]

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Rename Column.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Add New Columns

This Mule flow adds a new column to a table in a keyspace.

Studio flow for the Add New Table Column operation

In this flow, you configure:

  • An HTTP Listener component

  • A Set Variable component

  • A second Set Variable component

  • A Transform Message component

  • An Add New Table Column operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /addNewColumn.

Add the Set Variable Component

The first Set Variable component stores a value for the table name.

  1. In the Mule Palette view, search for set variable.

  2. Drag the Set Variable component onto the canvas, next to HTTP Listener.

  3. Configure the following fields in the Set Variable properties window:

    Field Value

    Name

    tableName

    Value

    #[payload.tableName]

Add the Second Set Variable Component

The second Set Variable component stores a value for the keyspace name.

  1. In the Mule Palette view, search for set variable.

  2. Drag the Set Variable component onto the canvas, next to HTTP Listener.

  3. Configure the following fields in the Set Variable properties window:

    Field Value

    Name

    keyspaceName

    Value

    #[payload.keyspaceName]

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Set Variable.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "column": payload.column,
      "type": payload.'type'
    } as Object {
      class : "org.mule.modules.cassandradb.api.AlterColumnInput"
    }

Add the Add New Table Column Operation

The Add New Table Column operation adds a new column.

  1. Drag the Add New Table Column operation onto the canvas, next to Transform Message.

  2. In the Add New Table Column configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Add New Table Column properties window:

    Field Value

    Table

    #[vars['tableName']]

    Keyspace name

    #[vars['keyspaceName']]

    Alter column input

    payload

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Add New Table Column.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Drop Columns

This Mule flow removes a column from a table in a keyspace.

Studio flow for the Drop Column operation

In this flow, you configure:

  • An HTTP Listener component

  • A Drop Column operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /dropColumn.

Add the Drop Column Operation

The Drop Column operation removes a column.

  1. Drag the Drop Column operation onto the canvas, next to HTTP Listener.

  2. In the Drop Column configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Drop Column properties window:

    Field Value

    Table

    #[payload.tableName]

    Keyspace name

    #[payload.keyspaceName]

    Column name

    payload.columnName

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Drop Column.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Execute a Cassandra Query Language (CQL) Query

This Mule flow executes the specified raw input query.

Studio flow for the Execute CQL Query operation

In this flow, you configure:

  • An HTTP Listener component

  • A Transform Message component

  • An Execute CQL Query operation

  • A second Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /executeCqlQuery.

Add the Transform Message Component

The Transform Message component converts the data from the keyspace to Java.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to HTTP Listener.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/java
    ---
    {
      "cqlQuery": payload.cqlQuery,
      "parameters": payload.parameters
    } as Object {
      class : "org.mule.modules.cassandradb.api.CQLQueryInput"
    }

Add the Execute CQL Query Operation

The Execute CQL Query operation executes the raw input query.

  1. Drag the Execute CQL Query operation onto the canvas, next to Transform Message.

  2. In the Execute CQL Query configuration, click the Connector configuration dropdown and select CassandraDB_Config.

Add the Second Transform Message Component

The second Transform Message component converts the data from the keyspace from Java to XML.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Execute CQL Query.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Drop Table

This Mule flow drops a table from the specified keyspace.

Studio flow for the Drop Table operation

In this flow, you configure:

  • An HTTP Listener component

  • A Drop Table operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /dropTable.

Add the Drop Table Operation

The Drop Table operation drops a table from the specified keyspace. If no keyspace is specified for the Drop Table operation, the table is created in the keyspace in the connection parameters.

  1. Drag the Drop Table operation onto the canvas, next to HTTP Listener.

  2. In the Drop Table configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Drop Table properties window:

    Field Value

    Table name

    payload.tableName

    Keyspace name

    #[payload.keyspaceName]

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Drop Table.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

Drop Keyspace

This Mule flow drops the specified keyspace and its values.

Studio flow for the Drop Keyspace operation

In this flow, you configure:

  • An HTTP Listener component

  • A Drop Keyspace operation

  • A Transform Message component

Configure HTTP Listener

Configure HTTP Listener to initiate a Mule flow when a call is made to the / account path on localhost, port 8081.

This example uses variables for some field values. You can either:

  • Replace the variables with their values in the code.

  • Provide the values for each variable in a properties file and then refer to that file from the connector configuration.

If you don’t know how to use a properties file, see Configuring Property Placeholders.

To configure HTTP Listener:

  1. Create a new Mule project in Studio.

  2. In the Mule Palette view, search for http and select the Listener operation:

  3. Drag the Listener operation onto the canvas.

  4. In the Listener configuration, click the Add icon next to the Connector configuration field to add a global element.

  5. Click OK to accept the defaults.

  6. Set the Path field to /dropKeyspace.

Add the Drop Keyspace Operation

The Drop Keyspace operation drops the keyspace and its values.

  1. Drag the Drop Keyspace operation onto the canvas, next to HTTP Listener.

  2. In the Drop Keyspace configuration, click the Connector configuration dropdown and select CassandraDB_Config.

  3. Configure the following fields in the Drop Keyspace properties window:

    Field Value

    Keyspace name

    payload.keyspaceName

Add the Transform Message Component

The Transform Message component converts the data from the keyspace.

  1. In the Mule Palette view, search for transform message.

  2. Drag the Transform Message component onto the canvas, next to Drop Keyspace.

  3. In the Transform Message configuration, overlay the brackets in the Output section with this XML:

    %dw 2.0
    output application/json
    ---
    payload

XML for the Manipulate Data in an Apache Cassandra Database Example

Paste this code into the Studio XML editor to quickly load the flow for this example into your Mule app:

<?xml version="1.0" encoding="UTF-8"?>

<mule xmlns:cassandra-db="http://www.mulesoft.org/schema/mule/cassandra-db" xmlns:ee="http://www.mulesoft.org/schema/mule/ee/core"
      xmlns:http="http://www.mulesoft.org/schema/mule/http"
      xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/ee/core http://www.mulesoft.org/schema/mule/ee/core/current/mule-ee.xsd
http://www.mulesoft.org/schema/mule/cassandra-db http://www.mulesoft.org/schema/mule/cassandra-db/current/mule-cassandra-db.xsd">

  <configuration-properties file="mule-app.properties" />
  <http:listener-config name="HTTP_Listener_config" doc:name="HTTP Listener config" doc:id="7b4310b7-4a49-4b37-8649-9247ae910399" >
    <http:listener-connection host="0.0.0.0" port="8081" />
  </http:listener-config>
  <cassandra-db:config name="CassandraDB_Config" doc:name="CassandraDB Config" doc:id="1ab180db-597d-455a-99fb-e006842cd052" >
    <cassandra-db:connection host="${config.host}" port="${config.port}" keyspace="${config.keyspace}" username="${config.username}" password="${config.password}" clusterName="${config.clusterName}" clusterNodes="${config.clusterNodes}"/>
  </cassandra-db:config>
  <flow name="GetTablesFromKeyspace" doc:id="e7d35ea3-58ed-4713-bbce-4ff6cbb41189" >
    <http:listener doc:name="Listener" doc:id="24838bde-79ae-4601-ac2b-00945831d7df" config-ref="HTTP_Listener_config" path="/getTablesFromKeyspace" />
    <cassandra-db:get-table-names-from-keyspace doc:name="Get table names from keyspace" doc:id="96e12e7b-8e90-4117-8ba6-5225d4af530a" config-ref="CassandraDB_Config" keyspaceName="#[payload.keyspaceName]"/>
    <ee:transform doc:name="Transform Message" doc:id="f3be8d87-27bd-470f-beb5-dbd2b81c24be" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="Insert" doc:id="ea181924-0b06-48ea-b007-c1b297db2cbd" >
    <http:listener doc:name="Listener" doc:id="5eceb9c9-bbad-4022-92a3-932e399bb4d6" config-ref="HTTP_Listener_config" path="/insert" />
    <ee:transform doc:name="Transform Message" doc:id="76763f2a-3860-4d73-84ad-33c0a7c485ed" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "id": payload.id,
  "name": payload.name,
  "event": payload.event
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:insert table="example_table" doc:name="Insert" doc:id="13224cf4-25d8-4f35-84e7-d211d4a3bdc5" config-ref="CassandraDB_Config" keyspaceName="example_keyspace"/>
    <ee:transform doc:name="Transform Message" doc:id="8888f973-3c80-4f56-b83c-792b40ba8cc4" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="Select" doc:id="2b70dea4-aadf-44a2-8c08-fee5a06cf8f5" >
    <http:listener doc:name="Listener" doc:id="ce7fb340-0292-45b5-a62e-29069d4f03ee" config-ref="HTTP_Listener_config" path="/select" />
    <cassandra-db:select doc:name="Select" doc:id="6a698c61-30eb-49e4-839a-c6412644c41f" config-ref="CassandraDB_Config">
      <cassandra-db:query >SELECT id, name, event FROM example_keyspace.example_table</cassandra-db:query>
    </cassandra-db:select>
    <ee:transform doc:name="Transform Message" doc:id="2782805e-1cf0-4808-96f1-99bd145759d0" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="Update" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/update" />
    <ee:transform doc:name="Transform Message" doc:id="c38ebb52-d614-4780-bae9-95d710f539d3" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "where":{
    id: payload.where
  },
  "columns":payload.columns
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:update table="example_table" doc:name="Update" doc:id="5edef28b-c636-4ce5-b59e-5843511c89c7" config-ref="CassandraDB_Config" keyspaceName="example_keyspace"/>
    <ee:transform doc:name="Transform Message" doc:id="beb77d6c-571b-4187-922e-afc7e89c8415" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="DeleteRows" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Copy_of_Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/deleteRows" />
    <ee:transform doc:name="Transform Message" doc:id="fdf8f121-8be3-4c73-8c5b-23df7c679c89" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "where": {
    id: payload.ids
  }
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:delete-rows table="example_table" doc:name="Delete rows" doc:id="3f9532e2-2fc6-4381-a2f6-90172994b2a7" config-ref="CassandraDB_Config" keyspaceName="example_keyspace"/>
    <ee:transform doc:name="Transform Message" doc:id="99fc2458-7548-44e1-9e31-ae29e04cd3c0" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="DeleteColumns" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/deleteColumns" />
    <ee:transform doc:name="Transform Message" doc:id="0d8fb61b-4afc-490b-be8c-d7f008efa1cf" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "columns": payload.columns,
  "where": {
    id:payload.where
  }
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:delete-columns-value table="example_table" doc:name="Delete columns value" doc:id="8ed01b4f-2cd4-4fcf-9d70-f560a6501f8e" config-ref="CassandraDB_Config" keyspaceName="example_keyspace">
      <cassandra-db:entities >
        <cassandra-db:entity value="#[payload.entities]" />
      </cassandra-db:entities>
    </cassandra-db:delete-columns-value>
    <ee:transform doc:name="Transform Message" doc:id="1f4f7f5d-7cfc-48fc-983c-a74a69576f8c" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="RenameColumn" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/renameColumn" />
    <cassandra-db:rename-column doc:name="Rename column" doc:id="f61c5f48-1f4f-46e6-9ab7-3021bb3eb4f5" config-ref="CassandraDB_Config" table="#[payload.tableName]" keyspaceName="#[payload.keyspaceName]" newColumnName="#[payload.newName]">
      <cassandra-db:old-column-name ><![CDATA[#[payload.oldName]]]></cassandra-db:old-column-name>
    </cassandra-db:rename-column>
    <ee:transform doc:name="Transform Message" doc:id="92b94afa-c0eb-4eb8-a05c-8d9ffcce000e" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="AddNewColumn" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/addNewColumn" />
    <set-variable value="#[payload.tableName]" doc:name="Set Variable" doc:id="40a2950e-58d2-4488-8b8d-6132ebcacfe8" variableName="tableName"/>
    <set-variable value="#[payload.keyspaceName]" doc:name="Set Variable" doc:id="29fe33b5-da79-4c42-97f1-a0f699cc532a" variableName="keyspaceName"/>
    <ee:transform doc:name="Transform Message" doc:id="af633bfc-5dbf-4849-a58a-2cb446d32920" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "column": payload.column,
  "type": payload.'type'
} as Object {
  class : "org.mule.modules.cassandradb.api.AlterColumnInput"
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:add-new-column doc:name="Add new column" doc:id="1ece4157-c45b-4298-9726-dec11c87fbf0" config-ref="CassandraDB_Config" table="#[vars['tableName']]" keyspaceName="#[vars['keyspaceName']]"/>
    <ee:transform doc:name="Transform Message" doc:id="335c584c-a1ae-4b69-bc24-1a0b7d1fe940" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="DropColumn" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="5b388d2a-886e-4d32-ba77-2ae3d388c766" config-ref="HTTP_Listener_config" path="/dropColumn"/>
    <cassandra-db:drop-column doc:name="Drop column" doc:id="cd602e74-3d04-4fa9-b96b-40351135268b" config-ref="CassandraDB_Config" table="#[payload.tableName]" keyspaceName="#[payload.keyspaceName]">
      <cassandra-db:column-name ><![CDATA[#[payload.columnName]]]></cassandra-db:column-name>
    </cassandra-db:drop-column>
    <ee:transform doc:name="Transform Message" doc:id="399e221f-9f0c-4767-828f-aa35575dce04" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="ExecuteCQLQuery" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/executeCqlQuery" />
    <ee:transform doc:name="Transform Message" doc:id="0eda8e3a-3f61-4461-b963-c0930eec9c1a" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/java
---
{
  "cqlQuery": payload.cqlQuery,
  "parameters": payload.parameters
} as Object {
  class : "org.mule.modules.cassandradb.api.CQLQueryInput"
}]]></ee:set-payload>
      </ee:message>
    </ee:transform>
    <cassandra-db:execute-cql-query doc:name="Execute cql query" doc:id="23531836-b75d-47a3-b88e-bfcca6e3c43d" config-ref="CassandraDB_Config"/>
    <ee:transform doc:name="Transform Message" doc:id="f6017333-6a54-4e7d-9a0a-37e75bb99e95" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="DropTable" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/dropTable" />
    <cassandra-db:drop-table doc:name="Drop table" doc:id="2b814d18-ea46-49ee-a7d5-f5663bdb64e7" config-ref="CassandraDB_Config" keyspaceName="#[payload.keyspaceName]">
      <cassandra-db:table-name ><![CDATA[#[payload.tableName]]]></cassandra-db:table-name>
    </cassandra-db:drop-table>
    <ee:transform doc:name="Transform Message" doc:id="ef72ee47-8ff0-40cc-8e94-2a33d867cde7" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
  <flow name="DropKeyspace" doc:id="81fa1da3-8a3d-460d-80d7-2499faacf3c3" >
    <http:listener doc:name="Listener" doc:id="51053b82-fa99-456b-bde4-36c87af4b633" config-ref="HTTP_Listener_config" path="/dropKeyspace" />
    <cassandra-db:drop-keyspace doc:name="Drop keyspace" doc:id="4dd3b152-bef6-474e-ac47-dfa476e8eafc" config-ref="CassandraDB_Config">
      <cassandra-db:keyspace-name ><![CDATA[#[payload.keyspaceName]]]></cassandra-db:keyspace-name>
    </cassandra-db:drop-keyspace>
    <ee:transform doc:name="Transform Message" doc:id="6b5c7894-5f53-41e5-9ae7-364fdbfc427b" >
      <ee:message >
        <ee:set-payload ><![CDATA[%dw 2.0
output application/json
---
payload]]></ee:set-payload>
      </ee:message>
    </ee:transform>
  </flow>
</mule>
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