java - jersey 适用于媒体类型文本，但不适用于 json 或 xml

Question

我的 Web 应用程序中有以下 Jersey 依赖项

    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-server</artifactId>
        <version>1.8</version>
    </dependency>

    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-client</artifactId>
        <version>1.8</version>
    </dependency>

当我使用 @Consumes(MediaType.APPLICATION_JSON) 或 @Produces(MediaType.APPLICATION_JSON) 时，我收到服务器错误。同样，如果我尝试使用 XML 。是因为我正在使用的库吗？

我的java类

import org.apache.log4j.Logger;

import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;


@Path("/test")
public class test {

    private static Logger logger = Logger.getLogger(test.class);



    @GET
    @Produces(MediaType.TEXT_PLAIN)  // works perfectly
    public Response getMsg()
    {
    logger.info("Inside getMsg()");

    String output = "hello world";

    return Response.status(200).entity(output).build();

    }

  /*   @GET                                      // I get a HTTP 500 , server error 
     @Path("/get")
     @Produces(MediaType.APPLICATION_JSON)
     public Track getTrackInJSON() {

         Track track = new Track();
         track.setTitle("Enter Sandman");
         track.setSinger("Metallica");

         return track;
     }
    */


    @GET
    @Path("/get")
    @Produces(MediaType.APPLICATION_JSON)
    public Response getTrackInJSON() {

        Track track = new Track();
        track.setTitle("Enter Sandman");
        track.setSinger("Metallica");

        //String test = " hello world";
        return Response.status(201).entity(track).build();

    }


    @POST
    @Path("/post")
    @Consumes(MediaType.APPLICATION_JSON)
 //   @Produces(Me)

    public Response createTrackInJSON(Track track) {
        String result = "Track saved : " + track;
        return Response.status(201).entity(result).build();

    }

    @POST
    @Path("/getValue")
    @Produces(MediaType.APPLICATION_XML)
    public void createXML()
    {
        String result = " get the track";
        //        return result.createXML();
        // check this line

    }



        }

当我使用 REST 客户端访问 @GET 资源时，出现此错误:

<u>Internal Server Error</u></p><p><b>description</b> <u>The server encountered an internal error that prevented it from fulfilling this request.</u>

当我使用其余客户端访问 @POST 资源时，出现此错误:

<u>Internal Server Error</u></p><p><b>description</b> <u>The server encountered an internal error that prevented it from fulfilling this request.</u>

这是我从 Tomcat 错误日志中得到的内容

Jan 29, 2014 11:00:21 AM com.sun.jersey.spi.container.ContainerResponse logException
SEVERE: Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException: com.sun.jersey.api.MessageException: A message body writer for Java class com.myProj.jsp.rest.Track, and Java type class com.gsipartners.apimgmtut
        at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:285)
        at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1437)
        at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
        at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
        at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
        at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
        at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
        at java.lang.Thread.run(Thread.java:662)
Caused by: com.sun.jersey.api.MessageException: A message body writer for Java class com.myProj.jsp.rest.Track, and Java type class com.myProj.jsp.rest.Track, and MIM
        ... 24 more

Track 类

public class Track {

    String title;
    String singer;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getSinger() {
        return singer;
    }

    public void setSinger(String singer) {
        this.singer = singer;
    }

    @Override
    public String toString() {
        return "Track [title=" + title + ", singer=" + singer + "]";
    }

}

Answer 1

您应该使用 JAXB 注释来注释您的 Track 类，Jersey 将使用其 MessageBodyWriter 将返回的实体(轨道)序列化/编码到响应输出流中。或者，您需要为 Track 类型提供您自己的 MessageBodyWriter 实现，以便在响应输出流中写入序列化表单。不然泽西不知道该怎么办。