问题描述
我正在测试 RESTful 服务,执行时出现异常,尽管我的类路径 (WEB-INF/lib) 中有以下 jar,但我没有使用 Maven,而且我的 JDK 版本是 1.5.有关此问题的其他问题无助于解决问题.
I am testing RESTful services and when I execute I am getting exceptions although I have the following jars in my class path(WEB-INF/lib), I am not using Maven and my JDK version is 1.5. Other questions regarding this issue didn't help to resolve the problem.
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
<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)
我该如何解决这个问题?
How can I resolve this issue?
推荐答案
确保您的项目中没有多个 Jersey 版本.从您提供的列表中,有来自 3 个不同版本(1.2、1.10、1.8)的模块.对于某些模块,Jersey 会检查模块的版本是否与核心的版本相同.如果不是,则模块的提供者(例如 MessageBodyReaders、MessageBodyWriters)未在运行时中注册.这可能是您的设置中的问题 - json vs core(1.8 vs 1.2).
Make sure you don't have multiple Jersey versions in your project. From the list you provided there are modules from 3 different versions (1.2, 1.10, 1.8). For some modules Jersey does a check that the version of a module is the same as the version of the core. If it's not then providers of the module (such as MessageBodyReaders, MessageBodyWriters) are not registered in the runtime. This can be problem in your setup - json vs core (1.8 vs 1.2).
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