（六）发送、接收SOAP消息（1）

一.为什么要用soap

• 原本我们使用web服务都是根据wsdl生成客户端（生成一堆java文件）然后再调用，本章节讲解如何用soap消息来替代这种方式。

二、SOAP消息格式

• SOAP（简单对象访问协议）是基于XML的消息格式。下面是一个简单的SOAP消息：

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

    <soap:Header>
    </soap:Header>

    <soap:Body>

        ... message data ...

        <soap:Fault>
        </soap:Fault>

    </soap:Body>

</soap:Envelope>

• 正如你可以看到一个SOAP消息包括：

  • Envelope
  • Header
  • Body
    • Message Data
    • Fault (optional)

  相同的SOAP消息结构用于客户端和Web Service服务器之间的请求和响应。

  Body内的Fault元素是可选的。只有Web服务中发生内部错误里才返回。否则，返回正常信息数据。

  SOAP不指定一个消息从客户端如何获取到Web Service，但最常见的情况是通过HTTP。

三、案例

　　3.1　　发布服务

• 服务接口

package service;

import javax.jws.WebParam;
import javax.jws.WebResult;
import javax.jws.WebService;

@WebService
public interface IFirstService {

    @WebResult(name = "addResult")
    public int add(@WebParam(name = "x") int x, @WebParam(name = "y") int y);
}

• 服务接口实现类

package service;

import javax.jws.WebParam;
import javax.jws.WebResult;
import javax.jws.WebService;

@WebService(endpointInterface = "service.IFirstService")
public class IFirstServiceImpl implements IFirstService {

    @Override
    public int add(int x, int y) {

        return x + y;
    }

}

• 发布服务

package publish;

import javax.xml.ws.Endpoint;

import service.IFirstServiceImpl;

public class TestPublish {
    public static void main(String[] args) {
        Endpoint.publish("http://localhost:3030/first", new IFirstServiceImpl());
        
        System.out.println("发布成功.....");
    }
}

•  查看wsdl文件

<definitions targetNamespace="http://service/" name="IFirstServiceImplService">
    <types>
        <xsd:schema>
            <xsd:import namespace="http://service/" schemaLocation="http://localhost:3030/first?xsd=1" />
        </xsd:schema>
    </types>
    <message name="add">
        <part name="parameters" element="tns:add" />
    </message>
    <message name="addResponse">
        <part name="parameters" element="tns:addResponse" />
    </message>
    <portType name="IFirstService">
        <operation name="add">
            <input wsam:Action="http://service/IFirstService/addRequest"
                message="tns:add" />
            <output wsam:Action="http://service/IFirstService/addResponse"
                message="tns:addResponse" />
        </operation>
    </portType>
    <binding name="IFirstServiceImplPortBinding" type="tns:IFirstService">
        <soap:binding transport="http://schemas.xmlsoap.org/soap/http"
            style="document" />
        <operation name="add">
            <soap:operation soapAction="" />
            <input>
                <soap:body use="literal" />
            </input>
            <output>
                <soap:body use="literal" />
            </output>
        </operation>
    </binding>
    <service name="IFirstServiceImplService">
        <port name="IFirstServiceImplPort" binding="tns:IFirstServiceImplPortBinding">
            <soap:address location="http://localhost:3030/first" />
        </port>
    </service>
</definitions>

• http://localhost:3030/first?xsd=1文件

<xs:schema version="1.0" targetNamespace="http://service/">
    <xs:element name="add" type="tns:add" />
    <xs:element name="addResponse" type="tns:addResponse" />
    <xs:complexType name="add">
        <xs:sequence>
            <xs:element name="x" type="xs:int" />
            <xs:element name="y" type="xs:int" />
        </xs:sequence>
    </xs:complexType>
    <xs:complexType name="addResponse">
        <xs:sequence>
            <xs:element name="addResult" type="xs:int" />
        </xs:sequence>
    </xs:complexType>
</xs:schema>

二、客户端发送soap消息、接收soap消息

• 这里不再用工具生成客户端

package test;

import java.net.URL;
import java.rmi.RemoteException;

import javax.xml.namespace.QName;
import javax.xml.soap.MessageFactory;
import javax.xml.soap.SOAPBody;
import javax.xml.soap.SOAPBodyElement;
import javax.xml.soap.SOAPEnvelope;
import javax.xml.soap.SOAPHeader;
import javax.xml.soap.SOAPMessage;
import javax.xml.soap.SOAPPart;
import javax.xml.ws.Dispatch;
import javax.xml.ws.Service;

import org.w3c.dom.Node;

public class TestMain {
    public static void main(String[] args) throws RemoteException {

        /**
         * 发送soap消息
         * 
         */

        try {
            // 创建一个message工厂
            MessageFactory factory = MessageFactory.newInstance();
            //获取soapMessage对象
            SOAPMessage send_message = factory.createMessage();
            SOAPPart soapPart=send_message.getSOAPPart();
            
            /**
             * 获取head和body对象
             */
            SOAPEnvelope soapEnvelope=soapPart.getEnvelope();
            
            SOAPBody soapBody=soapEnvelope.getBody();
            SOAPHeader soapHeader=soapEnvelope.getHeader();
            
            /**
             * 把数据封装到body元素里
             */
            
            //添加add标签
            QName addName=new QName("http://service/", "add","ns");
            SOAPBodyElement soapBodyElement=soapBody.addBodyElement(addName);
            
            //添加add标签中的子标签
            soapBodyElement.addChildElement(new QName("x")).setValue("1");;
            soapBodyElement.addChildElement(new QName("y")).setValue("10");;
            
            //打印发送到服务端的soap消息
            send_message.writeTo(System.out);
            
            /*
             * 将消息发送到服务端
             */
            URL wsdlDocumentLocation=new URL("http://localhost:3030/first?wsdl");
            QName serviceName=new QName("http://service/", "IFirstServiceImplService");
            Service service=Service.create(wsdlDocumentLocation, serviceName);
            
            /**
             * createDispatch方法第一个参数的Qname的构造方法的参数为port标签的name值
             * Mode
             * Service.Mode.MESSAGE：发送是XML的Doucment对象
             * Service.Mode.PAYLOAD：发送的是XML的字符串
             */
            QName portName=new QName("http://service/","IFirstServiceImplPort");
            Dispatch<SOAPMessage> dispatch=service.createDispatch(portName,SOAPMessage.class,Service.Mode.MESSAGE);
            
            
            //发送soap消息，并接收服务端返回的soap消息
            SOAPMessage respon_message=dispatch.invoke(send_message);
            
            System.out.println("服务端返回soap消息");
            respon_message.writeTo(System.out);
            
            /**
             * 解析从服务端返回的soap消息
             */
            SOAPPart part=respon_message.getSOAPPart();
             SOAPEnvelope envelope=part.getEnvelope();
            SOAPBody body=envelope.getBody();
            Node node=body.getElementsByTagName("addResult").item(0);
            
            System.out.println();
            System.out.println("result=="+node.getTextContent());
            
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

结果：