I am testing a Spring MVC application , I am calling a database service which returns an ArrayList. I want to return this ArrayList as a Json response to my Jsp, where I am going to iterate through it and render search results through jquery.
@RequestMapping(value = "/web/getprofiles", method = RequestMethod.GET)
public @ResponseBody
List getProfiles(HttpServletRequest request) {
ArrayList<SearchDO> searchResults = profileService.getProfileSearch();
return searchResults;
}
Getting following exception while returning the ArrayList from Controller method :
Oct 20, 2015 10:45:20 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [appServlet] in context with path [/web] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList] with root cause
java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList
at org.springframework.util.Assert.isTrue(Assert.java:68)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:124)
I am running this application on tomcat 7.0 with jdk 1.8 and Spring version 4.2.1.RELEASE.
Fix:
The exception here indicates that spring can not find a suitable converter to return ArrayList as a Json object as expected. To resolve this configure the resource resolver in your spring configuration xml.
Make you have specified <annotation-driven /> in spring configuration.
Spring configuration xml
<?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 -->
<!-- Enables the Spring MVC @Controller programming model -->
<annotation-driven />
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<context:component-scan base-package="com.testweb.controllers" />
<beans:bean
class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<beans:property name="useNotAcceptableStatusCode"
value="false" />
<beans:property name="contentNegotiationManager">
<beans:bean
class="org.springframework.web.accept.ContentNegotiationManager">
<beans:constructor-arg>
<beans:bean
class="org.springframework.web.accept.PathExtensionContentNegotiationStrategy">
<beans:constructor-arg>
<beans:map>
<beans:entry key="html" value="text/html" />
<beans:entry key="json" value="application/json" />
</beans:map>
</beans:constructor-arg>
</beans:bean>
</beans:constructor-arg>
</beans:bean>
</beans:property>
<beans:property name="viewResolvers">
<beans:list>
<beans:bean
class="org.springframework.web.servlet.view.BeanNameViewResolver"/>
<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean id="jspView"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
</beans:list>
</beans:property>
<beans:property name="defaultViews">
<beans:list>
<beans:bean
class="org.springframework.web.servlet.view.json.MappingJackson2JsonView" />
</beans:list>
</beans:property>
</beans:bean>
</beans:beans>
Make sure you have added required jackson dependencies in your pom.xml
<!-- Jackson JSON Mapper -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.5.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.5.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.5.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.jaxrs</groupId>
<artifactId>jackson-jaxrs-json-provider</artifactId>
<version>2.5.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.module</groupId>
<artifactId>jackson-module-jaxb-annotations</artifactId>
<version>2.5.2</version>
</dependency>
