我一直在尝试制作某个 API,我需要它以 JSON 格式在服务器上显示方法的结果。如果我尝试简单的
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
@Path("/messages")
public class MessageResource {
@GET
@Produces(MediaType.TEXT_PLAIN)
public String getMessages() {
return "Hello World!";
}
}
它可以工作,但是当我尝试使用我的类(以 JSON 格式返回值)时,它会在服务器上显示一些错误(它在普通控制台中工作)。
我是新手,希望我解释得足够好。
type Exception report
message org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:489)
org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
org.glassfish.jersey.servlet.internal.ResponseWriter.rethrow(ResponseWriter.java:278)
org.glassfish.jersey.servlet.internal.ResponseWriter.failure(ResponseWriter.java:260)
org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:509)
org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:334)
org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
org.glassfish.jersey.internal.Errors.process(Errors.java:315)
org.glassfish.jersey.internal.Errors.process(Errors.java:297)
org.glassfish.jersey.internal.Errors.process(Errors.java:267)
org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
valendor.messenger.ReturnJson.main(ReturnJson.java:27)
sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144)
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161)
org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$VoidOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:143)
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99)
org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389)
org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347)
org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326)
org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
org.glassfish.jersey.internal.Errors.process(Errors.java:315)
org.glassfish.jersey.internal.Errors.process(Errors.java:297)
org.glassfish.jersey.internal.Errors.process(Errors.java:267)
org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.36 logs.
这就是错误
最佳答案
显然,正如错误消息所述,您缺少 org.codehaus.jackson.map.ObjectMapper
类。您必须将 jackson-mapper
库添加到您的类路径,即您的 WEB-INF/lib
文件夹。
如果您使用 Maven 构建项目,请将以下依赖项添加到您的 pom.xml
中:
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-lgpl</artifactId>
<version>1.9.13</version>
</dependency>
(将版本替换为您要使用的版本,1.9.13是最新的ATM)
关于java - 无法在 apache tomcat 服务器上显示 json 格式的值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38976434/