java实现REST方式的webService

此文章是基于　　搭建Jquery+SpringMVC+Spring+Hibernate+MySQL平台

一. 简介　

    WebService有两种方式，一是SOAP方式，二是REST方式。SOAP是基于XML的交互，WSDL也是一个XML文档，可以使用WSDL作为SOAP的描述文件；REST是基于HTTP协议的交互，支持JSON、XML等交互，不需要WSDL。

二. jar包介绍

　　1. 点击此下载 apache-cxf-3.0.3，并在 lib 文件夹下得到：

commons-codec-1.9.jar
cxf-core-3.0.3.jar
cxf-rt-frontend-jaxrs-3.0.3.jar
cxf-rt-transports-http-3.0.3.jar
javax.ws.rs-api-2.0.1.jar

　　2. commons-httpclient-3.1.jar

三. 相关程序代码

　　1. applicationInterface.xml：spring配置文件

<?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:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:jaxrs="http://cxf.apache.org/jaxrs"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
        http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd">
        
    <!-- cxf发布rest服务 -->
    <import resource="classpath:META-INF/cxf/cxf.xml"/>   
    <!-- 这里是cxf2.x版本的配置，3.0没有了要去掉 --> 
    <!-- <import resource="classpath:META-INF/cxf/cxf-extension-soap.xml" /> -->
    <import resource="classpath:META-INF/cxf/cxf-servlet.xml" />
    
    <bean id="receiver" class="com.ims.test.webService.cxf.Receiver" />

    <jaxrs:server id="serviceContainer" address="/">    
        <jaxrs:serviceBeans>        
            <ref bean="receiver" />    
        </jaxrs:serviceBeans>    
    </jaxrs:server>
    <!-- cxf发布rest服务 -->
    
</beans>

　　2. web.xml：web工程配置文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:web="http://xmlns.jcp.org/xml/ns/javaee" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_4.xsd 
        http://xmlns.jcp.org/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
    version="2.4">

  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
            classpath:applicationInterface.xml
    </param-value>
  </context-param>
              
  <servlet>
      <servlet-name>CXFServlet</servlet-name>
      <servlet-class>org.apache.cxf.transport.servlet.CXFServlet</servlet-class>
  </servlet>
    
  <servlet-mapping>
      <servlet-name>CXFServlet</servlet-name>
      <url-pattern>/service/*</url-pattern>
  </servlet-mapping>

</web-app>

　　3. 基础服务

　　　　a. BaseService.java：接口

package com.ims.interfaces.webService.cxf;

import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;

public interface BaseService {
    @POST   
    @Consumes(MediaType.TEXT_HTML)
    @Produces(MediaType.TEXT_HTML)
    public void execute(@QueryParam("type") String type);
}

　　　　b. BaseServiceImpl.java：实现

package com.ims.interfaces.webService.cxf;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;

/**
 * 基础服务接口
 */
public abstract class BaseServiceImpl implements BaseService{
    @Context    
    protected HttpServletRequest request;
    @Context 
    protected HttpServletResponse response;
    
    @Override
    @POST
    @Consumes(MediaType.TEXT_HTML)
    @Produces(MediaType.TEXT_HTML) 
    public void execute(@QueryParam("type") String type) {        
        try {        
            // 获取请求类型
            RequestType reqType = RequestType.getTypeByCode(Integer.valueOf(type));
            
            // 获取HTTP请求体XML字符输入流
            BufferedReader reader = new BufferedReader(
                new InputStreamReader(
                    new BufferedInputStream(request.getInputStream()), "gb2312"));
            
            // 业务处理
            ResponseResult result = process(reqType, reader);
            // 设置响应编码
            response.setStatus(result.getStatus().getCode());
            
            // 输出响应体
            response.setCharacterEncoding("gb2312");
            OutputStream outputStream = response.getOutputStream();
            outputStream.write(result.getResult().getBytes("gb2312"));
        }
        catch (IOException ioe) {
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        }
    }

    public abstract ResponseResult process(RequestType reqType, BufferedReader reader);
}

　　4. Receiver.java：接收端类

package com.ims.test.webService.cxf;

import java.io.BufferedReader;

import javax.ws.rs.Path;

import com.ims.interfaces.webService.cxf.BaseServiceImpl;
import com.ims.interfaces.webService.cxf.RequestType;
import com.ims.interfaces.webService.cxf.ResponseResult;
import com.ims.interfaces.webService.cxf.ResponseStatus;


@Path(value = "/receive.do")
public class Receiver extends BaseServiceImpl {

    @Override
    public ResponseResult process(RequestType reqType, BufferedReader reader) {
        ResponseResult result = null;
        
        switch(reqType){
            case UNKNOWN:
                result = new ResponseResult(ResponseStatus.CODE400, "");
                break;
            default:
                break;
        }
        
        return result;
    }

}

　　5. Sender.java：发送端类

package com.ims.test.webService.cxf;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.StringRequestEntity;

public class Sender {
    
    public static void main(String[] args) {
        String url = "http://localhost:8090/ims/service/receive.do?type=0";
        String xmlString = "<?xml version="1.0" encoding="gbk"?>";
        post(url, xmlString); 
    }
    
    /**
     * 发送xml数据请求到server端
     * @param url xml请求数据地址
     * @param xmlString 发送的xml数据流
     * @return null发送失败，否则返回响应内容  
     */
    public static boolean post(String url,String xmlString){  
        boolean result = false;
        //创建httpclient工具对象   
        HttpClient client = new HttpClient();    
        //创建post请求方法   
        PostMethod myPost = new PostMethod(url);    
        //设置请求超时时间
        client.getHttpConnectionManager().getParams().setConnectionTimeout(300*1000); 

        try{    
            //设置请求头部类型   
            myPost.setRequestHeader("Content-Type","text/html");  
            myPost.setRequestEntity(new StringRequestEntity(xmlString,"text/html","gbk"));     
            int statusCode = client.executeMethod(myPost);    
            if(statusCode == HttpStatus.SC_OK){
                result = true;  
            }              
        }catch (Exception e) {    
            e.printStackTrace();    
        }finally{
            myPost.releaseConnection(); 
        }          
        return result;    
    }
}

四. 测试

　　eclipse上启动ims工程（webService接收端），以java执行Sender类，eclipse上调试查看Receive类是否收到xml文件

五. 备注

　　1. cxf 是支持多线程的，默认的线程池配置可查看 org.apache.cxf.workqueue.AutomaticWorkQueueImpl 源文件：

static final int DEFAULT_MAX_QUEUE_SIZE = 256;
    
。。。。。。。。。

public AutomaticWorkQueueImpl() {
        this(DEFAULT_MAX_QUEUE_SIZE);
    }    
    public AutomaticWorkQueueImpl(String name) {
        this(DEFAULT_MAX_QUEUE_SIZE, name);
    }    
    public AutomaticWorkQueueImpl(int max) {
        this(max, "default");
    }
    public AutomaticWorkQueueImpl(int max, String name) {
        this(max,
             0,
             25,
             5,
             2 * 60 * 1000L,
             name);
    }
    public AutomaticWorkQueueImpl(int mqs, 
                                  int initialThreads, 
                                  int highWaterMark, 
                                  int lowWaterMark,
                                  long dequeueTimeout) {
        this(mqs, initialThreads, highWaterMark, lowWaterMark, dequeueTimeout, "default");
    }    
    public AutomaticWorkQueueImpl(int mqs, 
                                  int initialThreads, 
                                  int highWaterMark, 
                                  int lowWaterMark,
                                  long dequeueTimeout,
                                  String name) {
        this.maxQueueSize = mqs == -1 ? DEFAULT_MAX_QUEUE_SIZE : mqs;
        this.initialThreads = initialThreads;
        this.highWaterMark = -1 == highWaterMark ? Integer.MAX_VALUE : highWaterMark;
        this.lowWaterMark = -1 == lowWaterMark ? Integer.MAX_VALUE : lowWaterMark;
        this.dequeueTimeout = dequeueTimeout;
        this.name = name;
        this.changeListenerList = new ArrayList<PropertyChangeListener>();
    }

。。。。。。。。。

protected synchronized ThreadPoolExecutor getExecutor() {
        if (executor == null) {
            threadFactory = createThreadFactory(name);
            executor = new ThreadPoolExecutor(lowWaterMark, 
                                              highWaterMark,
                                              TimeUnit.MILLISECONDS.toMillis(dequeueTimeout), 
                                              TimeUnit.MILLISECONDS, 
                                              new LinkedBlockingQueue<Runnable>(maxQueueSize),
                                              threadFactory) {
                @Override
                protected void terminated() {
                    ThreadFactory f = executor.getThreadFactory();
                    if (f instanceof AWQThreadFactory) {
                        ((AWQThreadFactory)f).shutdown();
                    }
                    if (watchDog != null) {
                        watchDog.shutdown();
                    }
                }
            };

　　2. 若要配置线程池参数，可配置 cxf-core-3.0.3.jarMETA-INFcxfcxf.xml 文件：

<bean id="default-wq" class="org.apache.cxf.workqueue.AutomaticWorkQueueImpl">
    <constructor-arg index="0">
        <!-- Max number of elements in the queue -->
        <value>20000</value>
    </constructor-arg>
    <constructor-arg index="1">
        <!-- name -->
        <value>default</value>
    </constructor-arg>
    <property name="name" value="default" />
    <property name="highWaterMark" value="30" />
</bean>