Spring REST Service with IOC?

Question

In the past I did some simple SOAP Services using Spring and IOC (application-context.xml where I state that my controller has 2 different DAOs etc. and Spring sets them for me)

Now I am trying to do a REST Service using Spring.

My Controller looks like this

@RestController
@RequestMapping("/")
public class MyController {

private MyDAO1 myDAO1;
private MyDAO2 myDAO2;

@RequestMapping("/name")
public MyTest getGreeting() {
    MyTest tst = new MyTest(1, "Hallo ");
    return tst;
}


public void setMyDAO1(MyDAO1 myDAO1) {
    this.myDAO1 = myDAO1;
}

public void setMyDAO2(MyDAO2 myDAO2) {
    this.myDAO2 = myDAO2;
}

My rest-servlet.xml contains this:

<?xml version="1.0" encoding="UTF-8"?>
<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">

<!-- Configure to plugin JSON as request and response in method handler -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="jsonMessageConverter" />
        </list>
    </property>
</bean>

<!-- Configure bean to convert JSON to POJO and vice versa -->
<bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
</bean>

<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName" value="java:comp/env/jdbc/InformixDB" />
    <property name="resourceRef" value="true" />
</bean>

<bean id="myDAO1" class="com.test.dao.MyDAO1">
    <property name="dataSource" ref="dataSource" />
</bean>
<bean id="myDAO2" class="com.test.dao.MyDAO2">
    <property name="dataSource" ref="dataSource" />
</bean>


<bean id="myController" class="com.test.controller.MyController">
    <property name="myDAO1" ref="myDAO1" />
    <property name="myDAO2" ref="myDAO2" />
</bean>


<context:component-scan base-package="com.test.controller.myController" />
<mvc:annotation-driven />

Now I get the error

java.lang.IllegalStateException: Ambiguous mapping found. Cannot map 'myController' bean method 
public com.test.entity.MyTest com.test.controller.MyController.getGreeting()
to {[//name],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}: There is already 'myController' bean method
public com.test.entity.MyTest com.test.controller.MyController.getGreeting() mapped.

When I remove the RequestMapping annotations I can deploy it on the tomcat but I don't know how to call the service

org.springframework.web.servlet.DispatcherServlet noHandlerFound
WARNING: No mapping found for HTTP request with URI [/MyTestService/getGreeting] in DispatcherServlet with name 'rest'

'rest' is the servlet map in the web.xml

What am I missing?

Answer 1

You are loading you controller twice, and Spring tries to map it twice :

• it is declared in rest-servlet.xml
• it is found as an annotated controller, due to @RestController annotation and the tag <context:component-scan base-package="de.cat.auftrag.controller" /> in rest-servlet.xml

You should either :

• remove the declaration <bean id="myController" ... from rest-servlet.xml , but you will have to autowire the DAOs
• remove the <context:component-scan ... tag, if you do not have any other bean to scan.

Answer 2

Why go through the trouble of doing things that Spring has already done for you?

@Controller // << See Here
@RequestMapping("/")
public class MyController {

@Autowired // << See Here
private MyDAO1 myDAO1;
@Autowired // << See Here
private MyDAO2 myDAO2;

@RequestMapping("/name")
public MyTest getGreeting() {
    MyTest tst = new MyTest(1, "Hallo ");
    return tst;
}

Your url is most likely the last package in your base package. In this case http://url:8080/rest/controller

And remove.

<bean id="myController" class="com.test.controller.MyController">
<property name="myDAO1" ref="myDAO1" />
<property name="myDAO2" ref="myDAO2" />
</bean>

If you're going to want to learn Spring... you'll have to pick your poison. Go XML or Annotations. Mixing the two is a recipe for a very very long and grueling learning process.