标签：code unit 调用 read sof 背景 throws update tcl
近期，由于项目的要求需要在自己的webservice中调用远程的WebAPI（Restful format）。自己的webservice程序是用Java编码写的，所以需要在其中实现一个Client来调用远程的Restful接口。
其实在自己的项目里面也有类似的调用，当时使用的是“JAXRSClientFactory”获得静态代理client。 由于这种方式需要依赖于远程调用的webservice接口（需要引入别人的jar包）。这就造成了高耦合。因此不适用。
所以需要以一种低耦合的方式来实现。便有了选型的想法。
在网上搜索一番后，基本定型为两种方式：
1.HttpClient
2.RestTemplate
接下来就分别列出两种方式的实现代码
import java.io.IOException; import java.text.MessageFormat; import java.util.ArrayList; import java.util.List; import java.util.concurrent.TimeUnit; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.ResponseHandler; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.BasicResponseHandler; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.message.BasicNameValuePair; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class HttpClientUtil { private static final Logger log = LoggerFactory.getLogger(HttpClientUtil.class); private CloseableHttpClient httpClient = HttpClients.createDefault(); public static String executePost(String url, String tdfBase64) throws Exception { String result = null; HttpPost httpPost = new HttpPost(url); httpPost.setEntity(new HttpEntity<String>(tdfBase64)); HttpResponse response = httpClient.execute(httpPost); if (response != null) { HttpEntity resEntity = response.getEntity(); if (resEntity != null) { result = EntityUtils.toString(resEntity, "utf-8"); } } return result; } } public static void main(String[] args) { // TODO Auto-generated method stub String url = "http://169.8.160.201:8080/xx/Webservice/Submit"; String base64Tdf = "MS4wMToxMzIdMS4wMjowMjAxHTEuMDM6MR8wMR4yHzAwHTEuMDQ6SVJRHTEuMDU6MjAxNjA1MDQdMS4wNjoxHTEuMDc6Q09HRU5UHTEuMDg6VEhBSUxBTkQdMS4wOTpTRVFVRU5DRU5PMTIzNB0xLjExOjE5LjY5HTEuMTI6MTkuNjkcMi4wMDE6MzEdMi4wMDI6MDAdMi4xNzY6MDA3MDA5HA=="; HttpClientUtil client = new HttpClientUtil(); String result=client.executePost(url, base64Tdf, ""); System.out.println(result); }
package com.biolive.client; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.HttpEntity; import org.springframework.http.client.SimpleClientHttpRequestFactory; import org.springframework.web.client.RestClientException; import org.springframework.web.client.RestTemplate; public class RestTemplateClient { private static final Logger log = LoggerFactory.getLogger(RestTemplateClient.class); private static final int connectTimeout= 5000; private static final int readTimeOut=5000; private RestTemplate restTemplate; public RestTemplateClient(){ SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory(); requestFactory.setConnectTimeout(connectTimeout); requestFactory.setReadTimeout(readTimeOut); restTemplate = new RestTemplate(requestFactory); } public String executePost(String url, String base64Tdf){ String result = null; restTemplate = new RestTemplate(); HttpEntity<String>request = new HttpEntity<String>(base64Tdf); try{ result=restTemplate.postForObject(url, request, String.class); }catch(RestClientException ex){ ex.printStackTrace(); log.info("call post interface error: " + ex.getMessage()); } return result; } public static void main(String[] args) { // TODO Auto-generated method stub String url = "http://169.8.160.201:8080/xx/Webservice/Submit"; String base64Tdf = "MS4wMToxMzIdMS4wMjowMjAxHTEuMDM6MR8wMR4yHzAwHTEuMDQ6SVJRHTEuMDU6MjAxNjA1MDQdMS4wNjoxHTEuMDc6Q09HRU5UHTEuMDg6VEhBSUxBTkQdMS4wOTpTRVFVRU5DRU5PMTIzNB0xLjExOjE5LjY5HTEuMTI6MTkuNjkcMi4wMDE6MzEdMi4wMDI6MDAdMi4xNzY6MDA3MDA5HA=="; RestTemplateClient client = new RestTemplateClient(); String result=client.executePost(url, base64Tdf); System.out.println(result); } }
首先，用两种方法都可以在只知道url和方法类型（GET/POST/PUT/UPDATE）的情况下完成任务，调用的方式也非常类似。 RestTemplate是Spring官方封装和推荐的client, 也可以根据自己的需要和Spring进行结合以及配置。
RestTemplate有两个构造方法，分别是：
public RestTemplate() {
/**
...初始化过程
*/
}
public RestTemplate(ClientHttpRequestFactory requestFactory) {
this();
setRequestFactory(requestFactory);
}
其中，第二个构造方法中可以传入ClientHttpRequestFactory参数，第一个进行默认初始化，因为我们经常需要对请求超时进行设置并能够对超时进行后续处理，而第一个构造方法，我们无法控制超时时间，第二个构造中的ClientHttpRequestFactory接口的实现类中存在timeout属性，因此选用第二个构造方法。
在spring配置文件中进行如下配置：
<!-- 配置RestTemplate -->
<!--Http client Factory-->
<bean id="httpClientFactory" class="org.springframework.http.client.SimpleClientHttpRequestFactory">
<property name="connectTimeout" value="${connectTimeout}"/>
<property name="readTimeout" value="${readTimeout}"/>
</bean>
<!--RestTemplate-->
<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
<constructor-arg ref="httpClientFactory"/>
</bean>
当然也可以直接使用：
SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
requestFactory.setConnectTimeout(1000);
requestFactory.setReadTimeout(1000);
RestTemplate restTemplate = new RestTemplate(requestFactory);注意：ClientHttpRequestFactory 接口有4个实现类，分别是：
http://www.cnblogs.com/softidea/p/5977375.html
http://blog.csdn.net/zpf336/article/details/73480810
Java - 在WebService中使用Client调用三方的RestAPI
标签：code unit 调用 read sof 背景 throws update tcl
原文地址：http://www.cnblogs.com/atuotuo/p/7125098.html
