Json multiparameters by using spring mvc and jackson - json

Question

i created a small json example... all worked quite fine, i'am just not able to send complex multiparameter to a service-method. With just one parameter it works... at the moment i'm not sure that my json call is wrong or something in my source/config is wrong.
First of all my lib-Dependencies:
org.springframework.spring-webmvc 4.0.6.RELEASE
org.springframework.spring-context 4.0.0.RELEASE
com.fasterxml.jackson.core.jackson-databind 2.2.3
Here is my spring-config:
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Configure to plugin JSON as request and response in method handler -->
<annotation-driven>
<message-converters>
<beans:bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<beans:property name="objectMapper">
<beans:bean class="com.test.webservice.EnvironmentObjectMapper" />
</beans:property>
</beans:bean>
</message-converters>
</annotation-driven>
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<!-- only components from this package can be wired by spring -->
<context:component-scan base-package="com.test.*" />
</beans:beans>
Here is the used ObjectMapper:
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
public class EnvironmentObjectMapper extends ObjectMapper{
/**
*
*/
private static final long serialVersionUID = -4831947927759735004L;
public EnvironmentObjectMapper() {
this.setVisibilityChecker(
getSerializationConfig().
getDefaultVisibilityChecker().
withFieldVisibility(JsonAutoDetect.Visibility.ANY).
withGetterVisibility(JsonAutoDetect.Visibility.NONE).
withSetterVisibility(JsonAutoDetect.Visibility.NONE).
withCreatorVisibility(JsonAutoDetect.Visibility.NONE).
withIsGetterVisibility(JsonAutoDetect.Visibility.NONE));
this.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
}
}
Here is a Simple-Test Code:
#RequestMapping(value = "/rest/test1", method = RequestMethod.POST)
public void test(#RequestBody String name, #RequestBody String name2){
System.out.println("Test - name: "+ name + " name2: " + name2);
}
To call this method i use the Firefox RESTClient. Header is set to Content-Type:application/json
Body is set to: {"name":"karl", "name2:"fritz"}
I get this response:
Status Code: 400 Bad Request
Cache-Control: must-revalidate,no-cache,no-store
Content-Length: 1379
Content-Type: text/html;charset=ISO-8859-1
Server: Jetty(7.2.0.v20101020)
and at the server this:
15:32:30.588 [qtp1879112077-17] DEBUG o.s.web.servlet.DispatcherServlet - DispatcherServlet with name 'appServlet' processing POST request for [/rest/test1]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.m.a.RequestMappingHandlerMapping - Looking up handler method for path /rest/test1
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.m.a.RequestMappingHandlerMapping - Returning handler method [public void com.test.webservice.JustAServiceController.test(java.lang.String,java.lang.String)]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Returning cached instance of singleton bean 'justAServiceController'
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.m.a.RequestResponseBodyMethodProcessor - Reading [class java.lang.String] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#3d467064]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Resolving exception from handler [public void com.test.webservice.JustAServiceController.test(java.lang.String,java.lang.String)]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.a.ResponseStatusExceptionResolver - Resolving exception from handler [public void com.test.webservice.JustAServiceController.test(java.lang.String,java.lang.String)]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.w.s.m.s.DefaultHandlerExceptionResolver - Resolving exception from handler [public void com.test.webservice.JustAServiceController.test(java.lang.String,java.lang.String)]: org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token
at [Source: org.eclipse.jetty.server.HttpInput#309efc1f; line: 1, column: 1]
15:32:30.588 [qtp1879112077-17] DEBUG o.s.web.servlet.DispatcherServlet - Null ModelAndView returned to DispatcherServlet with name 'appServlet': assuming HandlerAdapter completed request handling
15:32:30.588 [qtp1879112077-17] DEBUG o.s.web.servlet.DispatcherServlet - Successfully completed request
I have tried many different variants to set the parameters into the request body. But nothing worked. Anybody an idea what i did wrong? Thank you very much in advance.

Answer 1

You cannot have multiple #RequestBody annotations. #RequestBody annotated parameter is expected to hold the entire body of the request and bind to one object.
You should use different approach such as
Introduce a wrapper object that encapsulates your strings, and change your signature. e.g
Wrapper Object
class MyWrapper{
String name, name2;
//ToDo: Create constructors
String getname(){
return name;
}
String getName2(){
return name2;
}
//ToDo: create Setters
}
Your test code
#RequestMapping(value = "/rest/test1", method = RequestMethod.POST)
public void test(#RequestBody MyWrapper wrapper){
System.out.println("Test - name: "+ wrapper.getName() + " name2: " + wrapper.getName2());
}
Other options would be to pass the data with the URI path, or define custom annotations (which is more complex) see Passing multiple variables in #RequestBody to a Spring MVC controller using Ajax