Not able to send JSON object from Spring controller using Java

Question

I am returning a simple list object using spring controller. I have annotated correct with @ResponseBody to my method, but still its not able to convert from arraylist. I have added jackson-mapper-asl jar too.

My code of controller is

@Controller
@RequestMapping("/service/greeting")
public class SpringServiceController {


    @RequestMapping(value = "/customers", method = RequestMethod.GET)
    public @ResponseBody List<Employee> getCustomers() {
        EmployeeServiceImpl c = new EmployeeServiceImpl();
        return c.getCustomers();
    }
}

rest-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="
    http://www.springframework.org/schema/beans     
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
<context:component-scan base-package="com.biq.controller" />
<mvc:annotation-driven />

Log

java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList
at 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:113)
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:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
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)

What exactly im missing?

Maybee, ObjectMapper is not present as Spring Bean? I wonder about logs you have now. Could you provide it? — Oleg Cherednik, Sep 06 '17 at 14:36
@oleg.cherednik, sorry for not putting logs. I have updated now with log. Please check — shaik sha, Sep 06 '17 at 14:38
Yes. It seems so. Please check that you have e.g. Jackson in dependencies and ObjectMapper is available as Spring bean. List object could be mapped with default serializer, so you do not have to write custom one. — Oleg Cherednik, Sep 06 '17 at 14:39
have you tried: https://stackoverflow.com/questions/32905917/how-to-return-json-data-from-spring-controller-using-responsebody — Mário Fernandes, Sep 06 '17 at 14:39

score 0 · Answer 1 · answered Sep 06 '17 at 14:40

0

Try using @RestController instead @Controller.

Rest Controller annotation implicitly converts http response object into json/xml.

answered Sep 06 '17 at 14:40

Punit

324
1
4
17

Register an object mapper class . Annotate this with @component and scan that package as well. Spring will automatically create the bean out of this and will use it . – Punit Sep 06 '17 at 14:44

score 0 · Accepted Answer · answered Sep 06 '17 at 14:41

Try using the latest json 2 jar. Refer this for difference between the old Json and new json 2 lib here Have below jars in your classpath:

jackson-annotations-2.7.5.jar
jackson-core-2.7.5.jar
jackson-databind-2.7.5.jar

version can be different one. it should solve your issue. If you are using maven, then

<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
  <version>2.7.5</version>
</dependency>

This dependency will transitively add the abovelibraries to the classpath.

Excellent Sangam. Thanks a ton! – shaik sha Sep 06 '17 at 14:48 — shaik sha, Sep 06 '17 at 14:48

score 0 · Answer 3 · answered Sep 06 '17 at 14:46

Register an object mapper class . Annotate this with @component and scan that package as well. Spring will automatically create the bean out of this and will use it .

@Component
public class CustomObjectMapper extends ObjectMapper {


private static final long serialVersionUID = 1L;
private static final Logger LOG = LoggerFactory.getLogger(CustomObjectMapper.class);

public CustomObjectMapper() {
    super();
    @SuppressWarnings("deprecation")
    final AnnotationIntrospector introspector = new JaxbAnnotationIntrospector();
    this.setAnnotationIntrospector(introspector);
}
}

Not able to send JSON object from Spring controller using Java

3 Answers3