Red Hat Summit Red Hat SummitSupportoConsoleSviluppatoriInizia una provaContatti

Questo contenuto non è disponibile nella lingua selezionata.

Chapter 21. JSonPath

Overview
Copia collegamento

The JSonPath language provides a convenient syntax for extracting portions of a JSon message. The syntax of JSon is similar to XPath, but it is used to extract JSon objects from a JSon message, instead of acting on XML. The jsonpath DSL command can be used either as an expression or as a predicate (where an empty result gets interpreted as boolean false).

Adding the JSonPath package
Copia collegamento

To use JSonPath in your Camel routes, you need to add a dependency on camel-jsonpath to your project, as follows: 
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-jsonpath</artifactId>
  <version>${camel-version}</version>
</dependency>
Copy to Clipboard Toggle word wrap

Java example
Copia collegamento

The following Java example shows how to use the jsonpath() DSL command to select items in a certain price range: 
from("queue:books.new")
  .choice()
    .when().jsonpath("$.store.book[?(@.price < 10)]")
      .to("jms:queue:book.cheap")
    .when().jsonpath("$.store.book[?(@.price < 30)]")
      .to("jms:queue:book.average")
    .otherwise()
      .to("jms:queue:book.expensive")
Copy to Clipboard Toggle word wrap
If the JSonPath query returns an empty set, the result is interpreted as false. In this way, you can use a JSonPath query as a predicate.

XML example
Copia collegamento

The following XML example shows how to use the jsonpath DSL element to define predicates in a route: 
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="direct:start"/>
    <choice>
      <when>
        <jsonpath>$.store.book[?(@.price &lt; 10)]</jsonpath>
        <to uri="mock:cheap"/>
      </when>
      <when>
        <jsonpath>$.store.book[?(@.price &lt; 30)]</jsonpath>
        <to uri="mock:average"/>
      </when>
      <otherwise>
        <to uri="mock:expensive"/>
      </otherwise>
    </choice>
  </route>
</camelContext>
Copy to Clipboard Toggle word wrap

Suppress Exceptions
Copia collegamento

JSonPath will throw an exception if the path configured by the jsonpath expression is not found. The exception can be ignored by setting the SuppressExceptions option to true. For example, in the code below, adding the true option as part of the jsonpath parameters: 
from("direct:start")
    .choice()
        // use true to suppress exceptions
        .when().jsonpath("person.middlename", true)
            .to("mock:middle")
        .otherwise()
            .to("mock:other");
Copy to Clipboard Toggle word wrap
In XML DSL use the following syntax: 
<route>
  <from uri="direct:start"/>
  <choice>
    <when>
      <jsonpath suppressExceptions="true">person.middlename</jsonpath>
      <to uri="mock:middle"/>
    </when>
    <otherwise>
      <to uri="mock:other"/>
    </otherwise>
  </choice>
</route>
Copy to Clipboard Toggle word wrap

JSonPath injection
Copia collegamento

When using bean integration to invoke a bean method, you can use JSonPath to extract a value from the message and bind it to a method parameter. For example: 
// Java
public class Foo {
     
    @Consume(uri = "activemq:queue:books.new")
    public void doSomething(@JsonPath("$.store.book[*].author") String author, @Body String json) {
      // process the inbound message here
    }
}
Copy to Clipboard Toggle word wrap

Reference
Copia collegamento

For more details about JSonPath, see the JSonPath project page.
Torna in cima
Red Hat logoGithubredditYoutubeTwitter

Formazione

Prova, acquista e vendi

Community

Informazioni sulla documentazione di Red Hat

Aiutiamo gli utenti Red Hat a innovarsi e raggiungere i propri obiettivi con i nostri prodotti e servizi grazie a contenuti di cui possono fidarsi. Esplora i nostri ultimi aggiornamenti.

Rendiamo l’open source più inclusivo

Red Hat si impegna a sostituire il linguaggio problematico nel codice, nella documentazione e nelle proprietà web. Per maggiori dettagli, visita il Blog di Red Hat.

Informazioni su Red Hat

Forniamo soluzioni consolidate che rendono più semplice per le aziende lavorare su piattaforme e ambienti diversi, dal datacenter centrale all'edge della rete.

Theme

© 2025 Red Hat