找不到 Java 类 java.util.ArrayList 和 MIME 媒体类型 application/json 的消息正文编写器
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【中文标题】找不到 Java 类 java.util.ArrayList 和 MIME 媒体类型 application/json 的消息正文编写器【英文标题】：A message body writer for Java class java.util.ArrayList and MIME media type application/json was not found 【发布时间】：2018-04-20 01:35:14 【问题描述】：我正在尝试让 Web 服务正常工作，该服务返回 JSON（在 Tomcat 上带有球衣实现的 JAX-RS）。但是，我收到以下异常。我在这里查看了类似的问题，但没有一个解决方案对我有用，而且已经超过半天了:(
07-Nov-2017 20:47:17.109 SEVERE [http-nio-8080-exec-2] com.sun.jersey.spi.container.ContainerResponse.write A message body writer for Java class java.util.ArrayList, and Java type java.util.List<org.saurabh.Message>, and MIME media type application/json was not found.
The registered message body writers compatible with the MIME media type are:
application/json ->
com.sun.jersey.json.impl.provider.entity.JSONJAXBElementProvider$App
com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider$App
com.sun.jersey.json.impl.provider.entity.JSONListElementProvider$App
*/* ->
com.sun.jersey.core.impl.provider.entity.FormProvider
com.sun.jersey.core.impl.provider.entity.StringProvider
com.sun.jersey.core.impl.provider.entity.ByteArrayProvider
com.sun.jersey.core.impl.provider.entity.FileProvider
com.sun.jersey.core.impl.provider.entity.InputStreamProvider
com.sun.jersey.core.impl.provider.entity.DataSourceProvider
com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$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$SourceWriter
com.sun.jersey.server.impl.template.ViewableMessageBodyWriter
com.sun.jersey.json.impl.provider.entity.JSONJAXBElementProvider$General
com.sun.jersey.core.impl.provider.entity.XMLRootElementProvider$General
com.sun.jersey.core.impl.provider.entity.XMLListElementProvider$General
com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider$General
com.sun.jersey.json.impl.provider.entity.JSONListElementProvider$General
07-Nov-2017 20:47:17.110 SEVERE [http-nio-8080-exec-2] com.sun.jersey.spi.container.ContainerResponse.logException Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException: com.sun.jersey.api.MessageException: A message body writer for Java class java.util.ArrayList, and Java type java.util.List<org.saurabh.Message>, and MIME media type application/json was not found.
at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:284)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1510)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1419)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1409)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:409)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:558)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:733)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:475)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:500)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:754)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1376)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.sun.jersey.api.MessageException: A message body writer for Java class java.util.ArrayList, and Java type java.util.List<org.saurabh.Message>, and MIME media type application/json was not found.
... 30 more
资源类如下：
package org.saurabh;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import java.util.ArrayList;
import java.util.List;
@Path("/messages")
public class MessageResource
@GET
@Produces(MediaType.APPLICATION_JSON)
public List<Message> getMessages()
List<Message> messages = new ArrayList<Message>();
messages.add(new Message(1L, "Hello India", "Saurabh"));
messages.add(new Message(2L, "Hello World", "Saurabh"));
return messages;
模型类如下。我已经用 @XmlRootElement 注释对其进行了注释（如其他一些答案中所建议的那样），并且有一个无参数构造函数。
package org.saurabh;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class Message
private long id;
private String message;
private String user;
public Message()
public Message(long id, String message, String user)
this.id = id;
this.message = message;
this.user = user;
public long getId()
return id;
public void setId(long id)
this.id = id;
public String getMessage()
return message;
public void setMessage(String message)
this.message = message;
public String getUser()
return user;
public void setUser(String user)
this.user = user;
pom.xml 文件：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.saurabh</groupId>
<artifactId>JAX-RS-Rest-Tutorial</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-bundle</artifactId>
<version>1.18.3</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-moxy</artifactId>
<version>2.6</version>
</dependency>
</dependencies>
</project>
web.xml 文件：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<servlet>
<servlet-name>Example API</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>com.sun.jersey.spi.container.servlet.ServletContainer</param-name>
<param-value>com.example.jersey</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>Example API</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>
请注意，如果我将返回类型更改为 application/xml，那么它可以正常工作。只是对于JSON，它一直在给出这个错误。
@GET
@Produces(MediaType.APPLICATION_XML)
public List<Message> getMessages()
// works fine
【问题讨论】：
这可能会有所帮助***.com/questions/27935273/… @Jerry06：答案是使用Jackson，然后扩展配置类。我认为必须有开箱即用的方法来处理这个问题。 XmlRootElement 应该不是必需的。上次我使用它时，它与 JAX-WS 一起用于 SOAP Web 服务。 @LppEdd 删除 XmlRootElement 也无济于事:( @OneMoreError 看看这里mkyong.com/webservices/jax-rs/json-example-with-jersey-jackson 无论如何，我强烈建议升级到像 Spring 这样更易于理解的东西（参见 @RestController）。 【参考方案1】：您尝试使用的 MOXy 依赖项适用于 Jersey 2.x。您需要 1.x 版本的，因为这就是您正在使用的
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-json</artifactId>
<version>1.18.3</version>
</dependency>
【讨论】：
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