Sort

How can you sort the content of the message?

image

Use a special filter, a Message Translator , between other filters to sort the content of the message.

Options

The Sort eip supports the following options which are listed below.

Name Description Default Type

note

The note for this node.

String

description

The description for this node.

String

disabled

Whether to disable this EIP from the route during build time. Once an EIP has been disabled then it cannot be enabled later at runtime.

false

Boolean

expression

Required The expression to use for sorting. The message body is split into a list, sorted using this expression as the comparator key, and then reassembled.

ExpressionDefinition

comparator

Sets a reference to lookup for the comparator to use for sorting.

Comparator

Exchange properties

The Sort eip has no exchange properties.

How sorting works

Sort will by default sort the message body using a default Comparator that handles numeric values or uses the String representation.

You can also configure a custom Comparator to control the sorting.

An Expression can also be used, which performs the sorting, and returns the sorted message body. The value returned from the Expression must be convertible to java.util.List as this is required by the JDK sort operation.

Using Sort EIP

Imagine you consume text files and before processing each file, you want to be sure the content is sorted.

In the route below, it will read the file content and tokenize by line breaks so each line can be sorted.

  • Java

  • XML

  • YAML 

from("file:inbox")
    .sort(body().tokenize("\n"))
    .to("bean:MyServiceBean.processLine");
<route>
  <from uri="file:inbox"/>
  <sort>
    <tokenize token="\n"/>
  </sort>
  <to uri="bean:myServiceBean.processLine"/>
</route>
- route:
    from:
      uri: file:inbox
      steps:
        - sort:
            expression:
              tokenize:
                token: "\n"
        - to:
            uri: bean:myServiceBean.processLine

You can control how to sort using a custom java.util.Comparator :

  • Java

  • XML

  • YAML 

from("file:inbox")
    .sort().tokenize("\n").comparator("myComparator")
    .to("bean:MyServiceBean.processLine");
<route>
    <from uri="file:inbox"/>
    <sort comparator="myComparator">
        <tokenize token="\n"/>
    </sort>
    <to uri="bean:MyServiceBean.processLine"/>
</route>
- route:
    from:
      uri: file:inbox
      steps:
        - sort:
            comparator: myComparator
            expression:
              tokenize:
                token: "\n"
        - to:
            uri: bean:MyServiceBean.processLine
You can also refer to the custom comparator using #class: syntax as shown below:

  • Java

  • XML

  • YAML 

from("file:inbox")
    .sort().tokenize("\n").comparator("#class:com.mycompany.MyReverseComparator")
    .to("bean:MyServiceBean.processLine");

In Java DSL you can also provide the custom Comparator directly as the object as follows: 

from("file:inbox")
    .sort().body().comparator(new MyReverseComparator())
    .to("bean:MyServiceBean.processLine");
<route>
  <from uri="file:inbox"/>
  <sort comparator="#class:com.mycompany.MyReverseComparator">
    <tokenize token="\n"/>
  </sort>
  <bean ref="MyServiceBean" method="processLine"/>
</route>
- route:
    from:
      uri: file:inbox
      steps:
        - sort:
            comparator: "#class:com.mycompany.MyReverseComparator"
            expression:
              tokenize:
                token: "\n"
        - bean:
            ref: MyServiceBean
            method: processLine