如何更方便快捷的调用restful服务

这里我提供我一个restful服务，地址http://restful.wozsz.com/service/application.wadl

我们如何调用这个服务呢，常规方式当然是用httpclient了，它的弊端是对于符合要求的请求json需要自己封装，对于响应的json需要自己解析拿数据，而且不能太过于复杂，不然解析起来相当费劲，一层层的。

package com.somnus.http;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

import net.sf.json.JSONObject;

import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @Description: TODO
 * @author Somnus
 * @date 2015年12月16日 下午2:37:26
 * @version V1.0
 */
public class HttpClient {

    private transient Logger log = LoggerFactory.getLogger(this.getClass());

    @Test
    public void doPost2() throws IOException {
        String uriAPI = "http://120.26.68.243:8080/restful/service/com.somnus.resource.RestfulResource/getAccount";
        String result = "";
        // 创建HttpPost对象
        HttpPost httpRequst = new HttpPost(uriAPI);
        //生成json字符串
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username", "admin");
        jsonObject.put("password", "123456");
        String paramStr = jsonObject.toString();
        
        CloseableHttpResponse httpResponse = null;
        try {
        	httpRequst.addHeader("Content-type","application/json; charset=utf-8");  
        	httpRequst.setHeader("Accept", "application/json");  
            httpRequst.setEntity(new StringEntity(paramStr,Charset.forName("UTF-8")));
            // 生成连接
            CloseableHttpClient httpclient = HttpClients.createDefault();
            // 开始发送请求
            long startTime = System.currentTimeMillis();  
            httpResponse = httpclient.execute(httpRequst);
            long endTime = System.currentTimeMillis();
            // 获得响应状态码
            int statusCode = httpResponse.getStatusLine().getStatusCode();  
            log.info("statusCode:" + statusCode);  
            log.info("调用API 花费时间(单位：毫秒)：" + (endTime - startTime));
            // 取出应答字符串
            HttpEntity httpEntity = httpResponse.getEntity();
            result = EntityUtils.toString(httpEntity);
            if (statusCode == HttpStatus.SC_OK) {
            	System.out.println(result);
            } else{
            	throw new RuntimeException(String.format("\n\tStatus:%s\n\tError Message:%s", statusCode,result));
            }
        } catch (UnsupportedEncodingException e) {
            log.error(e.getMessage(), e);
        } catch (ClientProtocolException e) {
            log.error(e.getMessage(), e);
        } catch (IOException e) {
            log.error(e.getMessage(), e);
        } finally{
            httpResponse.close();
        }
    }
}

但是也有人肯定也知道基于jersey的api也是可以调用的

package com.somnus.support;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response.Status;

import org.junit.Test;

import com.somnus.domain.Request;
import com.somnus.domain.Response;
import com.somnus.resource.RestfulResource;
import com.somnus.rest.core.client.RESTfulJsonClientFactory;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

public class ClientCase {

	/**
	 * <p></p>  
	 * @author：Somnus
	 * @param args
	 */
	public static void main(String[] args) {
		Client client = Client.create();
		WebResource webResource = client.resource("http://120.26.68.243:8080/restful/service/com.somnus.resource.RestfulResource/getAccount");
		ClientResponse response = webResource.entity(new Request("admin","123456"),
				MediaType.APPLICATION_JSON).post(ClientResponse.class);
		System.out.println(response.getStatus());
		if(response.getStatus() == Status.OK.getStatusCode()){
			Response r =  response.getEntity(Response.class);
			System.out.println(r);
        }

}

基于jersey的api调用，它需要你提供服务的接口java文件，请求和响应java文件，当然这需要服务提供方，额外进行打包抽取出自己服务相关的的接口到jar包中提供给调用者，这对于以httpclient调用的方式来说确实麻烦了点，不过在技术可行上来说，抽取工作相当方便，根本无需人工复制粘贴，只需用maven插件进行抽取。

这是我作为服务方给调用者提供的jar包

我已经打包好，并上传到nexus，http://maven.wozsz.com

<!-- 指定Maven仓库 -->
	<repositories>
		<!-- oschina的maven仓库 -->
		<repository>
			<id>repository</id>
			<name>local private nexus</name>
			<url>http://maven.wozsz.com:88/content/groups/public/</url>
			<releases>
				<enabled>true</enabled>
			</releases>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
	</repositories>

<dependency>
  <groupId>com.somnus</groupId>
  <artifactId>ruo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
</dependency>

写到这里，读者肯定会说，这有什么嘛，我要基于jersey的api调，也要对其封装啊，而且服务方多了抽取工作，调用者还得额外添加api-jar包

可是如果我已经提供了一个组件给你呢，专门用来调用jersey服务的

<dependency>
  <groupId>com.somnus.rest.core</groupId>
  <artifactId>rest-core</artifactId>
  <version>3.2.0</version>
</dependency>

并且在spring项目中你可以以bean的形式把服务添加到项目中呢，比如这样

<?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.xsd">

    <bean id="restfulResource" class="com.somnus.rest.core.spring.RestfulJsonFactoryBean">
        <property name="serviceInterface" value="com.somnus.resource.RestfulResource" /> 
        <property name="serviceUrl" value="http://120.26.68.243:8080/restful/service/"/>
    </bean>
	
</beans> 

现在我们再次调用我提供的服务，你只需注入bean就可以了 

比如

package com.somnus.support;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.somnus.domain.Request;
import com.somnus.domain.Response;
import com.somnus.resource.RestfulResource;

@Service
public class TestServiceImpl {
	
	@Autowired
	private RestfulResource restfulResource;
	
	public void rest(){
		Response response = restfulResource.getAccount(new Request("admin","123456"));
		System.out.println(response);
	}
}

如果不是spring项目呢，可以用这个组件吗，回答是当然可以了，且看

package com.somnus.support;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response.Status;

import org.junit.Test;

import com.somnus.domain.Request;
import com.somnus.domain.Response;
import com.somnus.resource.RestfulResource;
import com.somnus.rest.core.client.RESTfulJsonClientFactory;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

public class ClientCase {

	private static final String BASE_URL = "http://120.26.68.243:8080/restful/service/";
	
	RestfulResource resource = RESTfulJsonClientFactory.createClient(RestfulResource.class, BASE_URL);
	
	@Test
	public void rest(){
		
		Response response = resource.getAccount(new Request("admin","123456"));
		
		System.out.println(response);
	}

}