我正在测试RESTful服务,当我执行时,我得到异常,尽管我的类路径(WEB-INF / lib)中有以下jar,但是我没有使用Maven,我的JDK版本是1.5.关于这个问题的其他问题没有帮助解决问题.
代码片段
@GET
@Produces("application/json")
//@Produces({MediaType.APPLICATION_JSON}) tried this,didn't work either
public List<Emp> getEmployees() {
List<Emp> empList = myDAO.getAllEmployees();
log.info("size " + empList.size());
return empList;
}
@XmlRootElement
public class Emp {
......
web.xml中
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>com.sun.jersey.config.property.packages</param-name>
<param-value>test.employees</param-value>
</init-param>
<init-param>
<param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
<param-value>true</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
罐子列表
jersey-server-1.2.jar jersey-core-1.2.jar jsr311-api-1.1.jar asm-3.1.jar jaxb-api-2.0.jar jaxb-impl-2.0.jar jackson-xc-1.2.0.jar jackson-jaxrs-1.2.0.jar jackson-mapper-asl-1.2.0.jar jackson-core-asl-1.2.0.jar jettison-1.2.jar jersey-client-1.2.jar jersey-servlet-1.10.jar jersey-json-1.8.jar
异常堆栈
SEVERE: A message body writer for Java class java.util.ArrayList,and Java type java.util.List<test.Emp>,and MIME media type application/json was not found
Nov 21,2013 11:47:26 AM com.sun.jersey.spi.container.ContainerResponse traceException
SEVERE: Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException
at javax.ws.rs.WebApplicationException.<init>(WebApplicationException.java:97)
at javax.ws.rs.WebApplicationException.<init>(WebApplicationException.java:55)
at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:267)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1035)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:947)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:939)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:399)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:478)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:663)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:719)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:376)
at com.evermind.server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:870)
at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:451)
at com.evermind.server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:218)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:119)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260)
at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:230)
at oracle.oc4j.network.ServerSocketAcceptHandler.access$800(ServerSocketAcceptHandler.java:33)
at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:831)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
at java.lang.Thread.run(Thread.java:595)
如何解决这个问题？
解决方法
确保您的项目中没有多个泽西版本.从您提供的列表中,有3个不同版本的模块(1.2,1.10,1.8).对于某些模块,Jersey会检查模块的版本是否与核心版本相同.如果不是,那么模块的提供者(如MessageBodyReaders,MessageBodyWriters)在运行时没有被注册.这可能是您的设置中的问题 – json vs core(1.8 vs 1.2).
