CODEWITHSUNDEEP
apache-camelapache-camel-3
user272735
user272735

Reputation: 10648

How to configure REST properties in Java-only Camel Main?

I'm working on a simple "hello-world" Camel3 (Camel version 3.4.3) REST API example with the following setup:

The example below works as expected but I fail to set jetty port. Therefore on every run the web server runs on a random port. How do I set the port (e.g. to 8081) in the Java code ? It also seems to be possible to set the port in application.properties file. Example of that option is also appreciated.

// https://camel.apache.org/components/latest/others/main.html
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.main.Main;
import org.apache.camel.main.RestConfigurationProperties;

import rest.dsl.generated.Api101;

public class App {
    public static void main(String[] args) throws Exception {
        Main main = new Main();

        // How do I set the rest properties ?
        // The code below doesn't seem to have effect.
        RestConfigurationProperties p = main.configure().rest()
        .withComponent("jetty")
        .withHost("localhost")
        .withPort(8081)
        ;
        main.configure().addConfiguration(p);

        // The route generated by camel-restdsl-swagger-plugin
        main.configure().addRoutesBuilder(
            new Api101()
        );

        // The actual route.
        main.configure().addRoutesBuilder(
            new RouteBuilder() {
                public void configure() {
                    from("direct:rest1")
                    .routeId("Rest1Route")
                    .log("START:")
                    .setBody(constant("{hello: \"Hello, World!\"}"))
                    .log("END:")
                    ;
                }
            }
        );

        main.run(args);
    }
}

Generated Api101 code:

package rest.dsl.generated;

import javax.annotation.Generated;
import org.apache.camel.builder.RouteBuilder;

/**
 * Generated from Swagger specification by Camel REST DSL generator.
 */
@Generated("org.apache.camel.generator.swagger.PathGenerator")
public final class Api101 extends RouteBuilder {
    /**
     * Defines Apache Camel routes using REST DSL fluent API.
     */
    public void configure() {
        rest("/api101")
            .get("/hello")
                .description("Basic Hello World")
                .to("direct:rest1");
    }
}

Compilation & run example:

/tmp/openapi$ mvn clean compile exec:java
[INFO] Scanning for projects...
[INFO] 
[INFO] ----------------------< com.stackoverflow:openapi >----------------------
[INFO] Building openapi 1.0
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ openapi ---
[INFO] Deleting /tmp/openapi/target
[INFO] 
[INFO] --- camel-restdsl-swagger-plugin:3.4.3:generate-with-dto (default) @ openapi ---
[INFO] reading from /tmp/openapi/swagger.yaml
[INFO] Generating Camel DSL source in directory: /tmp/openapi/target/generated-sources/restdsl-swagger
[INFO] Generating DTO classes using io.swagger:swagger-codegen-maven-plugin:2.4.12
[INFO] reading from /tmp/openapi/swagger.yaml
[WARNING] Output directory does not exist, or is inaccessible. No file (.swagger-codegen-ignore) will be evaluated.
[WARNING] 'host' not defined in the spec. Default to 'localhost'.
[INFO] writing file /tmp/openapi/target/generated-sources/swagger/src/main/java/io/swagger/client/model/InlineResponse200.java
[WARNING] 'host' not defined in the spec. Default to 'localhost'.
[INFO] 
[INFO] --- build-helper-maven-plugin:3.2.0:add-source (default) @ openapi ---
[INFO] Source directory: /tmp/openapi/target/generated-sources/restdsl-swagger added.
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ openapi ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ openapi ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to /tmp/openapi/target/classes
[INFO] 
[INFO] --- exec-maven-plugin:3.0.0:java (default-cli) @ openapi ---
[                    App.main()] BaseMainSupport                INFO  Using properties from: classpath:application.properties;optional=true
[                    App.main()] DefaultRoutesCollector         INFO  No additional Camel XML routes discovered from: classpath:camel/*.xml
[                    App.main()] DefaultRoutesCollector         INFO  No additional Camel XML rests discovered from: classpath:camel-rest/*.xml
[                    App.main()] AbstractCamelContext           INFO  Apache Camel 3.4.3 (camel-1) is starting
[                    App.main()] AbstractCamelContext           INFO  StreamCaching is not in use. If using streams then its recommended to enable stream caching. See more details at http://camel.apache.org/stream-caching.html
[                    App.main()] JettyHttpComponent             WARN  JMX disabled in CamelContext. Jetty JMX extensions will remain disabled.
[                    App.main()] log                            INFO  Logging initialized @8774ms to org.eclipse.jetty.util.log.Slf4jLog
[                    App.main()] Server                         INFO  jetty-9.4.29.v20200521; built: 2020-05-21T17:20:40.598Z; git: 77c232aed8a45c818fd27232278d9f95a021095e; jvm 11.0.8+10-post-Ubuntu-0ubuntu120.04
[                    App.main()] ContextHandler                 INFO  Started o.e.j.s.ServletContextHandler@4d9f9a55{/,null,AVAILABLE}
[                    App.main()] AbstractConnector              INFO  Started ServerConnector@157aa401{HTTP/1.1, (http/1.1)}{0.0.0.0:44267}
[                    App.main()] Server                         INFO  Started @8938ms
[                    App.main()] InternalRouteStartupManager    INFO  Route: route1 started and consuming from: jetty:http://0.0.0.0:0/api101/hello
[                    App.main()] InternalRouteStartupManager    INFO  Route: Rest1Route started and consuming from: direct://rest1
[                    App.main()] AbstractCamelContext           INFO  Total 2 routes, of which 2 are started
[                    App.main()] AbstractCamelContext           INFO  Apache Camel 3.4.3 (camel-1) started in 0.225 seconds
[              qtp1580225589-17] Rest1Route                     INFO  START:
[              qtp1580225589-17] Rest1Route                     INFO  END:
^C[ad #0 - CamelHangupInterceptor] DefaultMainShutdownStrategy    INFO  Received hang up - stopping the main instance.
[                    App.main()] AbstractCamelContext           INFO  Apache Camel 3.4.3 (camel-1) is shutting down
[ad #0 - CamelHangupInterceptor] DefaultMainShutdownStrategy    INFO  Waiting for CamelContext to graceful shutdown, elapsed: 0.000 seconds
[                    App.main()] DefaultShutdownStrategy        INFO  Starting to graceful shutdown 2 routes (timeout 45 seconds)
[el-1) thread #1 - ShutdownTask] DefaultShutdownStrategy        INFO  Route: Rest1Route shutdown complete, was consuming from: direct://rest1
[el-1) thread #1 - ShutdownTask] AbstractConnector              INFO  Stopped ServerConnector@157aa401{HTTP/1.1, (http/1.1)}{0.0.0.0:0}
[el-1) thread #1 - ShutdownTask] ContextHandler                 INFO  Stopped o.e.j.s.ServletContextHandler@4d9f9a55{/,null,UNAVAILABLE}
[el-1) thread #1 - ShutdownTask] DefaultShutdownStrategy        INFO  Route: route1 shutdown complete, was consuming from: rest://get:/api101:/hello
[                    App.main()] DefaultShutdownStrategy        INFO  Graceful shutdown of 2 routes completed in 0 seconds
[                    App.main()] MainLifecycleStrategy          INFO  CamelContext: camel-1 has been shutdown, triggering shutdown of the JVM.
[                    App.main()] AbstractCamelContext           INFO  Apache Camel 3.4.3 (camel-1) uptime 44.386 seconds
[                    App.main()] AbstractCamelContext           INFO  Apache Camel 3.4.3 (camel-1) is shutdown in 0.037 seconds
/tmp/openapi$

As you can see from the above the web server is available in port 44267:

Started ServerConnector@157aa401{HTTP/1.1, (http/1.1)}{0.0.0.0:44267}

And can be successfully accessed:

$ sudo netstat -tulpn | grep /java
tcp6       0      0 :::44267                :::*                    LISTEN      16926/java          
$ curl http://0.0.0.0:44267/api101/hello
{hello: "Hello, World!"}
$

Upvotes: 1

Views: 1336

Answers (1)

user272735
user272735

Reputation: 10648

I found an answer to my secondary question: this is the way to define the port with the properties:

$ cat src/main/resources/application.properties 
camel.rest.port=8081
$

This is also the method how to set all the other configuration options mention in the documentation. Might be obvious for Java veterans, but it was not obvious for me.

Upvotes: 1

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