java - 如何在 JAVA 中创建 JSON 输出

Question

我尝试用 Java 创建 JSON 输出。
==================这是带有元素的对象的代码:====================== =

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class LoginMobileProperties {

    private String username;
    private boolean status;
    private String message;

    public LoginMobileProperties(){

    }

    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public boolean getStatus() {
        return status;
    }
    public void setStatus(boolean status) {
        this.status = status;
    }
    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }


}

==================这是具有用于url调用的get函数的类:================== ======

    @GET
    @Path("login")
    @Produces("application/json")
    public LoginMobileProperties setLogin(
            @QueryParam("name") String name,
            @QueryParam("password") String password) {



        servlerResponse.addHeader("Allow-Control-Allow-Methods", "POST,GET,OPTIONS"); 
        servlerResponse.addHeader("Access-Control-Allow-Credentials", "true"); 
        servlerResponse.addHeader("Access-Control-Allow-Origin", "*"); 
        servlerResponse.addHeader("Access-Control-Allow-Headers", "Content-Type,X-Requested-With"); 
        servlerResponse.addHeader("Access-Control-Max-Age", "60"); 


        LoginMobileProperties loginMobileProperties = new LoginMobileProperties();

        loginMobileProperties.setUsername(name);
        loginMobileProperties.setStatus("true");
        loginMobileProperties.setMessage("test3");





             return loginMobileProperties;


    }

==================这是我打开网址时的完整错误代码:================== =========

Okt 29, 2012 11:32:02 AM com.sun.jersey.spi.container.ContainerResponse write
SEVERE: A message body writer for Java class LoginMobileProperties, and Java type class LoginMobileProperties, and MIME media type application/json was not found
Okt 29, 2012 11:32:02 AM com.sun.jersey.spi.container.ContainerResponse write
SEVERE: The registered message body writers compatible with the MIME media type are:
application/json ->
  com.sun.jersey.json.impl.provider.entity.JSONJAXBElementProvider$App
  com.sun.jersey.json.impl.provider.entity.JSONArrayProvider$App
  com.sun.jersey.json.impl.provider.entity.JSONObjectProvider$App
  com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider$App
  com.sun.jersey.json.impl.provider.entity.JSONListElementProvider$App
*/* ->
  com.sun.jersey.core.impl.provider.entity.FormProvider
  com.sun.jersey.json.impl.provider.entity.JSONJAXBElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONArrayProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONObjectProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONWithPaddingProvider
  com.sun.jersey.core.impl.provider.entity.StringProvider
  com.sun.jersey.core.impl.provider.entity.ByteArrayProvider
  com.sun.jersey.core.impl.provider.entity.FileProvider
  com.sun.jersey.core.impl.provider.entity.InputStreamProvider
  com.sun.jersey.core.impl.provider.entity.DataSourceProvider
  com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$General
  com.sun.jersey.core.impl.provider.entity.ReaderProvider
  com.sun.jersey.core.impl.provider.entity.DocumentProvider
  com.sun.jersey.core.impl.provider.entity.StreamingOutputProvider
  com.sun.jersey.core.impl.provider.entity.SourceProvider$SourceWriter
  com.sun.jersey.server.impl.template.ViewableMessageBodyWriter
  com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONListElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JacksonProviderProxy
  com.sun.jersey.core.impl.provider.entity.XMLRootElementProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLListElementProvider$General

Okt 29, 2012 11:32:02 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 LoginMobileProperties, and Java type class LoginMobileProperties, and MIME media type application/json was not found
    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:708)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:126)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:76)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at org.eclipse.equinox.http.jetty.internal.HttpServerManager$InternalHttpServiceServlet.service(HttpServerManager.java:317)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:924)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: com.sun.jersey.api.MessageException: A message body writer for Java class LoginMobileProperties, and Java type class LoginMobileProperties, and MIME media type application/json was not found
    ... 26 more

我的错误是什么？

Answer 1

您能否尝试将jersey-bundle-1.8.jar添加到您的类路径

无论如何我都不能相信这个答案Jersey + Json media type application/json was not found