Einfacher Servlet 3.0 basierter Bootstrapper für JAX-RS mit Jersey

[Thomas Darimont]

Hallo,

hier mal ein Beispiel für ein einfaches JAX-RS Setup ohne web.xml mittels dynamischer Servlet Konfiguration (Servlet 3.0):

Unser WebBootstrap Interface:

package de.tutorials.web.boot;

import javax.servlet.ServletContext;

public interface WebBoostrap {
	void boot(ServletContext servletContext);
}

Unser Boostraper -> Diese Klasse werden wir über den Java ServiceLoader Mechanismus laden lassen.

package de.tutorials.web.boot;

import java.util.Set;


import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import de.tutorials.web.boot.rest.RestBootstrap;

public class Bootstraper implements ServletContainerInitializer {

	public void onStartup(Set<Class<?>> classes, ServletContext servletContext) throws ServletException {
		configureJaxRsProvider(servletContext);
	}

	private void configureJaxRsProvider(ServletContext sc) {
		new RestBootstrap().boot(sc);
	}

}

Dazu legen wir in dem Verzeichnis:
src/main/resources/META-INF/services die Datei "javax.servlet.ServletContainerInitializer" an.
Inhalt:

de.tutorials.web.boot.Bootstraper

Hier unser RestBootstrap:

package de.tutorials.web.boot.rest;

import javax.servlet.ServletContext;
import javax.servlet.ServletRegistration.Dynamic;

import com.sun.jersey.api.json.JSONConfiguration;
import com.sun.jersey.spi.container.ResourceFilters;

import de.tutorials.web.boot.WebBoostrap;

public class RestBootstrap implements WebBoostrap {

	@Override
	public void boot(ServletContext sc) {
		configureJaxRsProvider(sc);
	}

	private void configureJaxRsProvider(ServletContext sc) {
		Dynamic servletConfig = sc.addServlet("ServletAdaptor",com.sun.jersey.spi.container.servlet.ServletContainer.class);
		servletConfig.setInitParameter(JSONConfiguration.FEATURE_POJO_MAPPING,"true");

		//Register some Debugging / Tracing Filters
		addResourceFilterTo(servletConfig,com.sun.jersey.api.container.filter.ResourceDebuggingFilterFactory.class.getName());
		addRequestResponseFilterTo(servletConfig,com.sun.jersey.api.container.filter.LoggingFilter.class.getName(), true, true);
		
		//Compression Filter to shrink requests / responses 
		addRequestResponseFilterTo(servletConfig,com.sun.jersey.api.container.filter.GZIPContentEncodingFilter.class.getName(), true, true);
		

		servletConfig.setLoadOnStartup(1);
		
		//All REST Resource Requests will be beneath /resources/...
		servletConfig.addMapping("/resources/*");
	}

	private void addResourceFilterTo(Dynamic servletConfig,String resourceFilterClass) {
		servletConfig.setInitParameter(ResourceFilters.class.getName(),resourceFilterClass);
	}

	private void addRequestResponseFilterTo(Dynamic servletConfig,String filterClassName, boolean filterRequest,boolean filterResponse) {
		if (filterRequest) {
			servletConfig.setInitParameter("com.sun.jersey.spi.container.ContainerRequestFilters",filterClassName);
		}
		if (filterResponse) {
			servletConfig.setInitParameter("com.sun.jersey.spi.container.ContainerResponseFilters",filterClassName);
		}
	}

}

Hier noch eine Beispiel resource:

package de.tutorials.web.services;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;

@Path("status")
public class StatusResource {
	
	@GET
	@Path("/")
	public Response getStatus(){
		return Response.ok("System: OK").build();
	}
}

Mit dieser Konfiguration kann man dann die Beispiel Resource unter dieser URL (Web App Path anpassen!) aufrufen:

http://localhost:8080/de.tutorials.web/resources/status/

Unsere Maven pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>de.tutorials</groupId>
    <artifactId>de.tutorials.web</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>de.tutorials.web</name>

    <properties>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<jersey.version>1.12</jersey.version>
		<servlet-api.version>3.0</servlet-api.version>
	</properties>

	<dependencies>

		<dependency>
			<groupId>com.sun.jersey</groupId>
			<artifactId>jersey-json</artifactId>
			<version>${jersey.version}</version>
		</dependency>

		<dependency>
			<groupId>com.sun.jersey.contribs</groupId>
			<artifactId>jersey-multipart</artifactId>
			<version>${jersey.version}</version>
		</dependency>

		<dependency>
			<groupId>com.sun.jersey</groupId>
			<artifactId>jersey-servlet</artifactId>
			<version>${jersey.version}</version>
		</dependency>

		<dependency>
			<groupId>com.sun.jersey</groupId>
			<artifactId>jersey-server</artifactId>
			<version>${jersey.version}</version>
		</dependency>

        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>6.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.1.1</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.1</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>6.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
        <pluginManagement>
        	<plugins>
        		<!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
        		<plugin>
        			<groupId>org.eclipse.m2e</groupId>
        			<artifactId>lifecycle-mapping</artifactId>
        			<version>1.0.0</version>
        			<configuration>
        				<lifecycleMappingMetadata>
        					<pluginExecutions>
        						<pluginExecution>
        							<pluginExecutionFilter>
        								<groupId>
        									org.apache.maven.plugins
        								</groupId>
        								<artifactId>
        									maven-dependency-plugin
        								</artifactId>
        								<versionRange>
        									[2.1,)
        								</versionRange>
        								<goals>
        									<goal>copy</goal>
        								</goals>
        							</pluginExecutionFilter>
        							<action>
        								<ignore></ignore>
        							</action>
        						</pluginExecution>
        					</pluginExecutions>
        				</lifecycleMappingMetadata>
        			</configuration>
        		</plugin>
        	</plugins>
        </pluginManagement>
    </build>

</project>

Gruß Tom