一个简单的Spring Web Service示例

刚接触web service，好不容易找到一篇spring-ws的例子，还琢磨了好长一段时间，很多概念性的问题都没弄清楚。只能依葫芦画瓢，照搬过来，稍微修改了一下，使结构更加清晰，原文出自http://fuxueliang.javaeye.com/blog/175184#。

基本环境：

JDK6、Tomcat 6.0、MyEclipse 6.6、spring 2.0、spring-ws-1.5.5

1、spring-ws-servlet.xml

这个地方出现了一段插曲，hello.wsdl放在WEB-INF下老是报错，说hello.wsdl找不到，后来放到classpath下才OK。

创建一个Web项目, 由于Spring Web Service是基于Spring MVC的, 在web.xml中添加如下servlet, 并在WEB-INF下建立SpringMVC的默认配置文件spring-ws-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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">
<bean id="payloadMapping" class="org.springframework.ws.server.endpoint.mapping.PayloadRootQNameEndpointMapping">
<property name="endpointMap">
<map>
<entry key="{http://www.ispring.com/ws/hello}eRequest">
<ref bean="helloEndpoint"/>
</entry>
</map>
</property>
</bean>

<bean id="hello" class="org.springframework.ws.wsdl.wsdl11.SimpleWsdl11Definition">
<!-- --><property name="wsdl" value="classpath://hello.wsdl"></property>
<!-- <property name="wsdl" value="/WEB_INF/hello.wsdl"></property> -->
<!-- <constructor-arg value="/WEB_INF/hello.wsdl"/> -->
</bean>

<bean id="helloEndpoint" class="com.sws.HelloEndPoint">
<property name="helloService" ref="helloService"></property>
</bean>

<bean id="helloService" class="com.sws.HelloServiceImpl"></bean>

</beans>

其中最主要的bean就是payloadMapping, 它定义了接收到的message与endpoint之间的mapping关系:将SOAP Body中包含的xml的根节点的QName为{http://www.fuxueliang.com/ws/hello}HelloRequest交给helloEndpoint处理.
SimpleWsdl11Definition这个bean则是定义了这个服务的wsdl, 访问地址是:

http://localhost:8080/springws/hello.wsdl.

2、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">
<!-- begin Spring配置
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
/WEB-INF/spring-ws-servlet.xml,
</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<listener>
<listener-class>
org.springframework.web.util.IntrospectorCleanupListener
</listener-class>
</listener>-->
<!-- end Spring配置 -->

<servlet>
<servlet-name>spring-ws</servlet-name>
<servlet-class>org.springframework.ws.transport.http.MessageDispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>spring-ws</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

</web-app>

3、hello.wsdl

<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:schema="http://www.ispring.com/ws/hello"
xmlns:tns="http://www.ispring.com/ws/hello/definitions"
targetNamespace="http://www.ispring.com/ws/hello/definitions">

<wsdl:types>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.ispring.com/ws/hello">
<element name="dRequest" type="string" />
<element name="dResponse" type="string" />
</schema>
</wsdl:types>

<wsdl:message name="bRequest">
<wsdl:part element="schema:dRequest" name="cRequest" />
</wsdl:message>
<wsdl:message name="bResponse">
<wsdl:part element="schema:dResponse" name="cResponse" />
</wsdl:message>

<wsdl:portType name="HelloPortType">
<wsdl:operation name="sayHello">
<wsdl:input message="tns:bRequest" name="aRequest" />
<wsdl:output message="tns:bResponse" name="aResponse" />
</wsdl:operation>
</wsdl:portType>

<wsdl:binding name="HelloBinding" type="tns:HelloPortType">
<soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http" />
<wsdl:operation name="sayHello">
<soap:operation soapAction="" />
<wsdl:input name="aRequest">
<soap:body use="literal" />
</wsdl:input>
<wsdl:output name="aResponse">
<soap:body use="literal" />
</wsdl:output>
</wsdl:operation>
</wsdl:binding>

<wsdl:service name="HelloService">
<wsdl:port binding="tns:HelloBinding" name="HelloPort">
<soap:address location="http://localhost:8088/springws/webservice" />
</wsdl:port>
</wsdl:service>
</wsdl:definitions>

4、HelloService.java

package com.sws;

public interface HelloService {

String sayHello(String name);

}

5、HelloServiceImpl.java

package com.sws;

public class HelloServiceImpl implements HelloService {

@Override
public String sayHello(String name) {
return "Hello, " + name + "!";
}

}

6、HelloEndPoint.java

实现一个EndPoint来处理接收到的xml及返回xml.当然, Spring Web Service提供了很多抽象的实现, 包括Dom4j, JDom等等.这里我们使用JDK自带的, 需要继承org.springframework.ws.server.endpoint.AbstractDomPayloadEndpoint.

package com.sws;

import org.springframework.util.Assert;
import org.springframework.ws.server.endpoint.AbstractDomPayloadEndpoint;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

public class HelloEndPoint extends AbstractDomPayloadEndpoint{

/**
* Namespace of both request and response
*/
public static final String NAMESPACE_URI = "http://www.ispring.com/ws/hello";

/**
* The local name of the expected request
*/
public static final String HELLO_REQUEST_LOCAL_NAME = "eRequest";

/**
* The local name of the created response
*/
public static final String HELLO_RESPONSE_LOCAL_NAME = "fResponse";

private HelloService helloService;

@Override
protected Element invokeInternal(Element requestElement, Document document)throws Exception {
Assert.isTrue(NAMESPACE_URI.equals(requestElement.getNamespaceURI()), "Invalid namespace");
Assert.isTrue(HELLO_REQUEST_LOCAL_NAME.equals(requestElement.getLocalName()), "Invalid local name");

NodeList children = requestElement.getChildNodes();
Text requestText = null;
for(int i=0; i<children.getLength(); i++){
if(children.item(i).getNodeType() == Node.TEXT_NODE){
requestText = (Text) children.item(i);
}
}

if(requestText == null){
throw new IllegalArgumentException("Could not find request text node");
}

String response = helloService.sayHello(requestText.getNodeValue());
Element responseElement = document.createElementNS(NAMESPACE_URI, HELLO_RESPONSE_LOCAL_NAME);
Text responseText = document.createTextNode(response);
responseElement.appendChild(responseText);
return responseElement;
}

public HelloService getHelloService() {
return helloService;
}

public void setHelloService(HelloService helloService) {
this.helloService = helloService;
}

}

7、HelloWebServiceClient.java(saaj实现)

package com.sws;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;

import javax.xml.soap.MessageFactory;
import javax.xml.soap.Name;
import javax.xml.soap.SOAPBodyElement;
import javax.xml.soap.SOAPConnection;
import javax.xml.soap.SOAPConnectionFactory;
import javax.xml.soap.SOAPEnvelope;
import javax.xml.soap.SOAPException;
import javax.xml.soap.SOAPFault;
import javax.xml.soap.SOAPMessage;

public class HelloWebServiceClient {

public static final String NAMESPACE_URI = "http://www.ispring.com/ws/hello";

public static final String PREFIX = "tns";

private SOAPConnectionFactory connectionFactory;

private MessageFactory messageFactory;

private URL url;

public HelloWebServiceClient(String url) throws UnsupportedOperationException, SOAPException, MalformedURLException{
connectionFactory = SOAPConnectionFactory.newInstance();
messageFactory = MessageFactory.newInstance();
this.url = new URL(url);
}

private SOAPMessage createHelloRequest() throws SOAPException{
SOAPMessage message = messageFactory.createMessage();
SOAPEnvelope envelope = message.getSOAPPart().getEnvelope();
Name helloRequestName = envelope.createName("eRequest",PREFIX,NAMESPACE_URI);
SOAPBodyElement helloRequestElement = message.getSOAPBody().addBodyElement(helloRequestName);
helloRequestElement.setValue("ispring");
return message;
}

public void callWebService() throws SOAPException{
SOAPMessage request = createHelloRequest();
SOAPConnection connection = connectionFactory.createConnection();
SOAPMessage response = connection.call(request, url);
if(!response.getSOAPBody().hasFault()){
writeHelloResponse(response);
}else{
SOAPFault fault = response.getSOAPBody().getFault();
System.err.println("Received SOAP Fault");
System.err.println("SOAP Fault Code : " + fault.getFaultCode());
System.err.println("SOAP Fault String : " + fault.getFaultString());
}
}

private void writeHelloResponse(SOAPMessage message) throws SOAPException{
SOAPEnvelope envelope = message.getSOAPPart().getEnvelope();
Name helloResponseName = envelope.createName("fResponse",PREFIX,NAMESPACE_URI);
Iterator childElements = message.getSOAPBody().getChildElements(helloResponseName);
SOAPBodyElement helloResponseElement = (SOAPBodyElement)childElements.next();
String value = helloResponseElement.getTextContent();
System.out.println("Hello Response [" + value + "]");
}

public static void main(String[] args) throws UnsupportedOperationException, MalformedURLException, SOAPException {
String url = "http://localhost:8088/SpringWS";
HelloWebServiceClient helloClient = new HelloWebServiceClient(url);
helloClient.callWebService();
}

}