泽西岛:如何将杰克逊添加到Servlet Holder

Question

我正在使用Jersey创建一个嵌入式Jetty webapp.我不知道如何在这里添加杰克逊自动JSON serde:

    ServletHolder jerseyServlet = context.addServlet(
       org.glassfish.jersey.servlet.ServletContainer.class, "/*");
    jerseyServlet.setInitOrder(0);

    jerseyServlet.setInitParameter(
        ServerProperties.PROVIDER_CLASSNAMES,
        StringUtils.join(
            Arrays.asList(
                HealthCheck.class.getCanonicalName(),
                Rest.class.getCanonicalName()),
            ";"));

    // Create JAX-RS application.
    final Application application = new ResourceConfig()
        .packages("com.example.application")
        .register(JacksonFeature.class);

    // what do I do now to tie this to the ServletHolder?

如何ResourceConfig在ServletHolder中注册这个,以便在使用注释的地方使用Jackson @Produces(MediaType.APPLICATION_JSON)？这是嵌入式Jetty应用程序的完整主类

package com.example.application.web;

import com.example.application.api.HealthCheck;
import com.example.application.api.Rest;
import com.example.application.api.Frontend;
import org.apache.commons.lang.StringUtils;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.glassfish.jersey.jackson.JacksonFeature;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.ServerProperties;

import javax.ws.rs.core.Application;
import java.util.Arrays;

public class JettyStarter {

public static void main(String[] args) throws Exception {

    ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
    context.setContextPath("/");
    Server jettyServer = new Server(9090);
    jettyServer.setHandler(context);
    ServletHolder jerseyServlet = context.addServlet(
     org.glassfish.jersey.servlet.ServletContainer.class, "/*");
    jerseyServlet.setInitOrder(0);

    jerseyServlet.setInitParameter(
        ServerProperties.PROVIDER_CLASSNAMES,
        StringUtils.join(
            Arrays.asList(
                HealthCheck.class.getCanonicalName(),
                Rest.class.getCanonicalName()),
            ";"));

    // Create JAX-RS application.
    final Application application = new ResourceConfig()
        .packages("com.example.application")
        .register(JacksonFeature.class);


    try {
        jettyServer.start();
        jettyServer.join();
    } catch (Exception e) {
        System.out.println("Could not start server");
        e.printStackTrace();
    } finally {
        jettyServer.destroy();
    }
}
}

Answer 1

一种方法是只是包裹ResourceConfig在明确建设的ServletContainer,因为看到这里.

测试你的例子

public class RestServer {

    public static void main(String[] args) throws Exception {

        // Create JAX-RS application.
        final ResourceConfig application = new ResourceConfig()
                .packages("jersey.jetty.embedded")
                .register(JacksonFeature.class);

        ServletContextHandler context 
                 = new ServletContextHandler(ServletContextHandler.SESSIONS);
        context.setContextPath("/");
        Server jettyServer = new Server(9090);
        jettyServer.setHandler(context);
        ServletHolder jerseyServlet = new ServletHolder(new
                org.glassfish.jersey.servlet.ServletContainer(application));
        jerseyServlet.setInitOrder(0);

        context.addServlet(jerseyServlet, "/*");

        // ... removed property (init-param) to compile. 

        try {
            jettyServer.start();
            jettyServer.join();
        } catch (Exception e) {
            System.out.println("Could not start server");
            e.printStackTrace();
        } finally {
            jettyServer.destroy();
        }
    }
}

你也可以......

如果不更改原始帖子中的任何其他内容,只需设置init参数即可扫描Jackson提供程序包

jerseyServlet.setInitParameter(ServerProperties.PROVIDER_PACKAGES,
        "com.fasterxml.jackson.jaxrs.json;"
      + "jersey.jetty.embedded"  // my package(s)
);

请注意,您尝试使用ResourceConfig似乎有点多余,因为您已经在init参数中配置了类.您也可以明确地删除每个类,并像我一样扫描整个包.

你也可以......

只需使用您需要的Jackson提供程序类.您可以查看jar,您将看到的不仅仅是编组/解组提供程序(Jackson [JAXB] JsonProvider),就像ExceptionMappers一样.您可能不喜欢这些映射器和魔杖来配置您自己的.在这种情况下,就像我说的那样,只需要包含您需要的提供程序.例如

jerseyServlet.setInitParameter(ServerProperties.PROVIDER_CLASSNAMES,
      "com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider");

jerseyServlet.setInitParameter(ServerProperties.PROVIDER_PACKAGES, 
      "jersey.jetty.embedded"  // my package(s)
);

经过进一步测试......

不知道是什么版本的球衣,但我用的泽西2.15(含jersey-media-json-jackson:2.15),并且在不背离只是扫描任何进一步的配置我的包,我的资源类,杰克逊功能已经启用.这是自动发现功能的一部分.我相信这是杰克逊功能的2.8或2.9.因此,如果您使用的是后者,我认为您不需要明确配置任何内容,至少从我测试的内容开始:-)

UPDATE

所有上述示例都已使用以下Maven pom.xml进行了测试

<?xml version="1.0" encoding="UTF-8"?>
<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>com.underdog.jersey</groupId>
    <artifactId>jersey-jetty-embedded</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
        <jersey.version>2.15</jersey.version>
        <jetty.version>9.2.6.v20141205</jetty.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
        </dependency>
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-server</artifactId>
            <version>${jetty.version}</version>
        </dependency>
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-servlet</artifactId>
            <version>${jetty.version}</version>
        </dependency>
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-servlets</artifactId>
            <version>${jetty.version}</version>
        </dependency>
    </dependencies>

        <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

和资源类

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

@Path("/json")
public class JsonResource {

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public Response getJson() {
        Resource resource = new Resource();
        resource.hello = "world";
        return Response.ok(resource).build();
    }

    public static class Resource {
        public String hello;
    }
}

使用路径

http://localhost:9090/json