严重: Servlet.service() for servlet [xxx] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class com.xxx.pojo.EasyUIDataGrid] with root causejava.lang.IllegalArgumentException: No converter found for return value of type: class com.xxx.pojo.EasyUIDataGridat org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:187)at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:174)at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81)at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:132)at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)at org.apache..JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)at java.lang.Thread.run(Thread.java:745)
缺少json的依赖包，导入依赖就可以了。
<!-- Jackson Json处理工具包 --><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><jackson.version>2.8.7</jackson.version></dependency>
