Example of REST service in spring framework 3.1

application-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mongo="http://www.springframework.org/schema/data/mongo"
	xsi:schemaLocation="http://www.springframework.org/schema/data/mongo http://www.springframework.org/schema/data/mongo/spring-mongo-1.0.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<!-- The configuration of the application. -->
	
	<context:annotation-config/>
	
	<mongo:mongo host="172.21.0.151" port="27017" />
	
	<bean id="mongoTemplate" class="org.springframework.data.document.mongodb.MongoTemplate">
		<constructor-arg ref="mongo" />
		<constructor-arg name="databaseName" value="db" />
		<constructor-arg name="defaultCollectionName" value="transaction_history" />
	</bean>

	<!-- Weaves in transactional advice around @Transactional methods -->
	<!-- <tx:annotation-driven transaction-manager="transactionManager" /> -->

	<!-- Service Layer -->
	<bean id="transactionManager" class="dgw.services.TransactionManager">
		<property name="transactionHistoryDao" ref="transactionHistoryDao" />
	</bean>
	
	<!-- Daos -->	
	<bean id="transactionHistoryDao" class="dgw.dao.TransactionHistoryDAOImpl" />
	
</beans>

build.properties

# Ant properties for building the springapp

appserver.home=C:\\opt\\apache-tomcat-7.0.23
# for Tomcat 5 use $appserver.home}/server/lib
# for Tomcat 6 use $appserver.home}/lib
appserver.lib=C:\\opt\\apache-tomcat-7.0.23\\lib

deploy.path=C:\\opt\\apache-tomcat-7.0.23\\webapps

tomcat.manager.url=http://localhost:8080/manager/text
tomcat.manager.username=tomcat
tomcat.manager.password=s3cret

build.xml

<?xml version="1.0"?>

<project name="dgw" basedir="." default="usage">
    <property file="build.properties"/>

    <property name="src.dir" value="src"/>
    <property name="web.dir" value="war"/>
    <property name="build.dir" value="${web.dir}/WEB-INF/classes"/>
    <property name="name" value="dgw"/>

    <path id="master-classpath">
        <fileset dir="${web.dir}/WEB-INF/lib">
            <include name="*.jar"/>
        </fileset>
        <!-- We need the servlet API classes: -->
        <!--  * for Tomcat 5/6 use servlet-api.jar -->
        <!--  * for other app servers - check the docs -->
        <fileset dir="${appserver.lib}">
            <include name="servlet*.jar"/>
        </fileset>
        <pathelement path="${build.dir}"/>
    </path>

    <target name="usage">
        <echo message=""/>
        <echo message="${name} build file"/>
        <echo message="-----------------------------------"/>
        <echo message=""/>
        <echo message="Available targets are:"/>
        <echo message=""/>
        <echo message="build     --> Build the application"/>
        <echo message="deploy    --> Deploy application as directory"/>
        <echo message="deploywar --> Deploy application as a WAR file"/>
        <echo message="install   --> Install application in Tomcat"/>
        <echo message="reload    --> Reload application in Tomcat"/>
        <echo message="start     --> Start Tomcat application"/>
        <echo message="stop      --> Stop Tomcat application"/>
        <echo message="list      --> List Tomcat applications"/>
        <echo message=""/>
    </target>

    <target name="build" description="Compile main source tree java files">
        <mkdir dir="${build.dir}"/>
        <javac destdir="${build.dir}" source="1.5" target="1.5" debug="true"
               deprecation="false" optimize="false" failonerror="true">
            <src path="${src.dir}"/>
            <classpath refid="master-classpath"/>
        </javac>
    </target>

    <target name="deploy" depends="build" description="Deploy application">
        <copy todir="${deploy.path}/${name}" preservelastmodified="true">
            <fileset dir="${web.dir}">
                <include name="**/*.*"/>
            </fileset>
        </copy>
    </target>

    <target name="deploywar" depends="build" description="Deploy application as a WAR file">
        <war destfile="${name}.war"
             webxml="${web.dir}/WEB-INF/web.xml">
            <fileset dir="${web.dir}">
                <include name="**/*.*"/>
            </fileset>
        </war>
        <copy todir="${deploy.path}" preservelastmodified="true">
            <fileset dir=".">
                <include name="*.war"/>
            </fileset>
        </copy>
    </target>
    
<!-- ============================================================== -->
<!-- Tomcat tasks - remove these if you don't have Tomcat installed -->
<!-- ============================================================== -->

    <path id="catalina-ant-classpath">
        <!-- We need the Catalina jars for Tomcat -->
        <!--  * for other app servers - check the docs -->
        <fileset dir="${appserver.lib}">
            <include name="catalina-ant.jar"/>
        	<include name="tomcat-coyote.jar"/>
        	<include name="tomcat-util.jar" />
        </fileset>
    	<fileset dir="${appserver.home}/bin">
    	    <include name="tomcat-juli.jar"/>
    	</fileset>
    </path>

    <taskdef name="install" classname="org.apache.catalina.ant.DeployTask">
        <classpath refid="catalina-ant-classpath"/>
    </taskdef>
    <taskdef name="reload" classname="org.apache.catalina.ant.ReloadTask">
        <classpath refid="catalina-ant-classpath"/>
    </taskdef>
    <taskdef name="list" classname="org.apache.catalina.ant.ListTask">
        <classpath refid="catalina-ant-classpath"/>
    </taskdef>
    <taskdef name="start" classname="org.apache.catalina.ant.StartTask">
        <classpath refid="catalina-ant-classpath"/>
    </taskdef>
    <taskdef name="stop" classname="org.apache.catalina.ant.StopTask">
        <classpath refid="catalina-ant-classpath"/>
    </taskdef>

    <target name="install" description="Install application in Tomcat">
        <install url="${tomcat.manager.url}"
                 username="${tomcat.manager.username}"
                 password="${tomcat.manager.password}"
                 path="/${name}"
                 war="${name}"/>
    </target>

    <target name="reload" description="Reload application in Tomcat">
        <reload url="${tomcat.manager.url}"
                 username="${tomcat.manager.username}"
                 password="${tomcat.manager.password}"
                 path="/${name}"/>
    </target>

    <target name="start" description="Start Tomcat application">
        <start url="${tomcat.manager.url}"
                 username="${tomcat.manager.username}"
                 password="${tomcat.manager.password}"
                 path="/${name}"/>
    </target>

    <target name="stop" description="Stop Tomcat application">
        <stop url="${tomcat.manager.url}"
                 username="${tomcat.manager.username}"
                 password="${tomcat.manager.password}"
                 path="/${name}"/>
    </target>

    <target name="list" description="List Tomcat applications">
        <list url="${tomcat.manager.url}"
                 username="${tomcat.manager.username}"
                 password="${tomcat.manager.password}"/>
    </target>

<!-- End Tomcat tasks -->

</project>

project-structure.txt

./src/Controller.java
./test/
./war/WEB-INF/
              |-> application-context.xml
              |-> transaction-servlet.xml
              |-> web.xml

Test.java

package springapp.test;



import java.io.IOException;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.GetMethod;
import org.codehaus.jackson.map.ObjectMapper;
import org.junit.Assert;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;

import dgw.model.TransactionHistoryModelList;

public class Test {

	/**
	 * server URL ending with the servlet mapping on which the application can be reached.
	 */
	private static final String BASE_URL = "http://localhost:8080/dgw/rest/transactions";

	
	private static HttpEntity<String> prepareGet(MediaType type) {
		HttpHeaders headers = new HttpHeaders();
		headers.setContentType(type);
		HttpEntity<String> entity = new HttpEntity<String>(headers);
		return entity;
	}
	
	
	@org.junit.Test
	public void gimmeAllTransactionsXMLformat() throws HttpException, IOException {
		
		String url = BASE_URL + "/all";
		HttpClient httpClient = new HttpClient();
		GetMethod getRequest = new GetMethod(url);
		try{
			getRequest.setRequestHeader(new Header("Accept","application/xml")); 
			int responseCode = httpClient.executeMethod(getRequest);
			Assert.assertTrue(responseCode == 200);
			//TODO convert the xml into string and validate result with some assertions, in the meantime, printing result in the console...
			System.out.println(getRequest.getResponseBodyAsString());
		}finally{
			getRequest.releaseConnection();
		}
	}
	@org.junit.Test
	public void gimmeAllTransactionsJSONformat() throws HttpException, IOException {
		
		String url = BASE_URL + "/all";
		HttpClient httpClient = new HttpClient();
		GetMethod getRequest = new GetMethod(url);
		try{
			getRequest.setRequestHeader(new Header("Accept","application/json")); 
			int responseCode = httpClient.executeMethod(getRequest);
			Assert.assertTrue(responseCode == 200);
			ObjectMapper mapper = new ObjectMapper();
			TransactionHistoryModelList result = mapper.readValue(getRequest.getResponseBodyAsString(), TransactionHistoryModelList.class);
			Assert.assertTrue(result.getCount() == 10);
			Assert.assertTrue(result.getTransactions().size() == 10);
			
		}finally{
			getRequest.releaseConnection();
		}
	}
	@org.junit.Test
	public void gimmeAllTransactionsFilterByTerms() throws HttpException, IOException {
		
		String url = BASE_URL + "/accounts/21000/terms/INTERNAL+TRANSFER";
		HttpClient httpClient = new HttpClient();
		GetMethod getRequest = new GetMethod(url);
		try{
			getRequest.setRequestHeader(new Header("Accept","application/json")); 
			int responseCode = httpClient.executeMethod(getRequest);
			Assert.assertTrue(responseCode == 200);
			ObjectMapper mapper = new ObjectMapper();
			TransactionHistoryModelList result = mapper.readValue(getRequest.getResponseBodyAsString(), TransactionHistoryModelList.class);
			Assert.assertTrue(result.getCount() == 10);
			Assert.assertTrue(result.getTransactions().size() == 10);
		}finally{
			getRequest.releaseConnection();
		}
	}
	
	@org.junit.Test
	public void gimmeAllInterestTransctionsForAGivenAccount() throws HttpException, IOException {
		
		String url = BASE_URL + "/accounts/21001/terms/INTEREST";
		HttpClient httpClient = new HttpClient();
		GetMethod getRequest = new GetMethod(url);
		try{
			getRequest.setRequestHeader(new Header("Accept","application/json")); 
			int responseCode = httpClient.executeMethod(getRequest);
			Assert.assertTrue(responseCode == 200);
			//System.out.println("Code:" + responseCode);
			System.out.println("Body:" + getRequest.getResponseBodyAsString());
		}finally{
			getRequest.releaseConnection();
		}
	}
	/*
	@Test
	public void createAccount() {
		String url = BASE_URL + "/accounts";
		// use a unique number to avoid conflicts
		String number = String.format("12345%4d", random.nextInt(10000));
		Account account = new Account(number, "John Doe");
		account.addBeneficiary("Jane Doe");
		URI newAccountLocation = restTemplate.postForLocation(url, account);
		
		Account retrievedAccount = restTemplate.getForObject(newAccountLocation, Account.class);
		assertEquals(account, retrievedAccount);
		assertNotNull(retrievedAccount.getEntityId());
	}
	
	@Test
	public void addAndDeleteBeneficiary() {
		// perform both add and delete to avoid issues with side effects
		String addUrl = BASE_URL + "/accounts/{accountId}/beneficiaries";
		URI newBeneficiaryLocation = restTemplate.postForLocation(addUrl, "David", 0);
		Beneficiary newBeneficiary = restTemplate.getForObject(newBeneficiaryLocation, Beneficiary.class);
		assertEquals("David", newBeneficiary.getName());
		
		restTemplate.delete(newBeneficiaryLocation);
		try {
			restTemplate.getForObject(newBeneficiaryLocation, Beneficiary.class);
			fail("Should have received 404 Not Found after deleting beneficiary at " + newBeneficiaryLocation);
		} catch (HttpClientErrorException e) {
			assertEquals(HttpStatus.NOT_FOUND, e.getStatusCode());
		}
	}*/
}

TransactionController.java

package dgw.controller;

import java.util.ArrayList;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import dgw.model.TransactionHistoryModelList;
import dgw.services.TransactionManager;


@Controller
@RequestMapping("/transactions")
public class TransactionController  {
    protected final Logger logger = LoggerFactory.getLogger(TransactionController.class);
    private TransactionManager transactionManager;
	
	public void setTransactionManager(TransactionManager transactionManager) {
		this.transactionManager = transactionManager;
	}
	
    
    @RequestMapping(value="/all", method=RequestMethod.GET, headers = "Accept=application/xml, application/json")
    public @ResponseBody  TransactionHistoryModelList retrieveTransactions() {
    	TransactionHistoryModelList list = new TransactionHistoryModelList();
    	list.setTransactions(transactionManager.queryAllInternalTransferCIF());
    	list.setCount(list.getTransactions().size());
    	
    	return list;
    }
    
    @RequestMapping(value="/accounts/{account}/terms/{terms}", method=RequestMethod.GET, headers = "Accept=application/xml, application/json")
    public @ResponseBody TransactionHistoryModelList retrieveTransactionsByTerms(@PathVariable String account, @PathVariable String terms) {
    	ArrayList<String> lTerms = new ArrayList<String>();
    	
    	// Determine the account number
    	if ("all".equalsIgnoreCase(account)== false){
    		lTerms.add(account);
    	}
    	
    	// Determine the searching criteria terms
    	if (terms != null && terms.length() != 0){
    		if (terms.contains("+")){
    			//case of multi term being entered (+) separator
	    		String[] split = StringUtils.split(terms, "+");
	    		for (String term : split)
	    			lTerms.add(term);
    		}else{
    			//case of single term being entered
    			lTerms.add(terms);
    		}
    	}
    	
    	
    	// Determine the searching terms
    	
    	TransactionHistoryModelList list = new TransactionHistoryModelList();
    	list.setTransactions(transactionManager.queryByCIFandTerms("01999999", lTerms.toArray(new String[lTerms.size()] ), 10, 0));
    	
    	return list;
    }
    
}

transactions-servlet.xml

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

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

  	<context:component-scan base-package="springapp.controller"/>	

		 
	<!-- To enable @RequestMapping process on type level and method level -->
	<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
	<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
		<property name="messageConverters">
			<list>
				
				<ref bean="marshallingConverter" />
				<!-- 
				<ref bean="atomConverter"  />
				 -->
				<ref bean="jsonConverter" />
			</list>
		</property>
	</bean>

   <bean id="marshallingConverter" class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter">
    	<constructor-arg ref="jaxbMarshaller" />
    	<property name="supportedMediaTypes" value="application/xml"/>
	</bean>
<!-- 
	<bean id="atomConverter" class="org.springframework.http.converter.feed.AtomFeedHttpMessageConverter">
		<property name="supportedMediaTypes" value="application/atom+xml" />
	</bean>
 -->
	<bean id="jsonConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
		<property name="supportedMediaTypes" value="application/json" />
	</bean>

	
	<bean id="jaxbMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
		<property name="classesToBeBound">
			<list>
				<value>dgw.model.TransactionHistoryModel</value>
				<value>dgw.model.TransactionHistoryModelList</value>
			</list>
		</property>
	</bean>

 
	<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
		<property name="mediaTypes">
		    <map>
		        <entry key="xml" value="application/xml"/>
		        <entry key="html" value="text/html"/>
		        <entry key="json" value="application/json" />
		    </map>
		</property>
		<property name="defaultContentType" value="application/xml" />
		<!--  
		<property name="viewResolvers">
		    <list>
		        <bean class="org.springframework.web.servlet.view.BeanNameViewResolver"/>
		        <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
					<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
					<property name="prefix" value="/WEB-INF/jsp/"/>
					<property name="suffix" value=".jsp"/>
				</bean>
		    </list>
		</property>
		-->
	</bean>
	
	<!--bean id="viewResolver" class="org.springframework.web.servlet.view.BeanNameViewResolver" /-->

	<bean id="transactionController" class="dgw.controller.TransactionController">
		<property name="transactionManager" ref="transactionManager" />
		<!-- <property name="jaxb2Mashaller" ref="jaxbMarshaller" /> -->
	</bean>

</beans>

web.xml

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

<web-app version="2.4"
         xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
         http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" >
 
 	<display-name>(REST API)</display-name>
 	<!--
		Beans in these files will makeup the configuration of the root web
		application context
	-->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/application-context.xml</param-value>
	</context-param>
 
 	<!--
		Bootstraps the root web application context before servlet
		initialization
	-->
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
 
 	<!--
		Deploys the 'transactions' dispatcher servlet whose configuration resides
		in /WEB-INF/accounts-servlet-config.xml
	-->
	<servlet>
		<servlet-name>rest</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>/WEB-INF/transactions-servlet-config.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
 
 
  <!-- Maps all URLs starting with /app to the 'accounts' servlet. -->
	<servlet-mapping>
		<servlet-name>rest</servlet-name>
		<url-pattern>/rest/*</url-pattern>
	</servlet-mapping>
  
  <!-- TODO to be removed after REST api is implemented -->
   <jsp-config>
    <taglib>
      <taglib-uri>/spring</taglib-uri>
      <taglib-location>/WEB-INF/tld/spring-form.tld</taglib-location>
    </taglib>
  </jsp-config>


</web-app>