HttpClient的使用-白红宇

HttpClient的使用

阅读量：6184 次

发布时间：2019-06-21

本文共 9103 字，大约阅读时间需要 30 分钟。

HttpClient的使用：

1）httpClient的简单使用：

import java.net.URI;import java.util.ArrayList;import java.util.List;import org.apache.http.NameValuePair;import org.apache.http.client.config.RequestConfig;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.client.utils.URIBuilder;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;public class HttpClientDemo {	public static void main(String[] args) throws Exception {		// 1.创建Httpclient对象		CloseableHttpClient httpclient = HttpClients.createDefault();		// 2.1创建http GET请求，并设置参数		String url = "http://www.jxn.com/";		URI uri = new URIBuilder(url).setParameter("name", "jack").setParameter("age", "1").build();		HttpGet httpGet = new HttpGet(uri);		// 2.2创建http POST请求，并设置参数		HttpPost httpPost = new HttpPost(url);		List
    
      parameters = new ArrayList
     
      ();		parameters.add(new BasicNameValuePair("name", "jack"));		parameters.add(new BasicNameValuePair("age", "1"));		UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);		httpPost.setEntity(formEntity);						// 3.构建请求配置信息		RequestConfig config = RequestConfig.custom().setConnectTimeout(1000) // 创建连接的最长时间				.setConnectionRequestTimeout(500) // 从连接池中获取到连接的最长时间				.setSocketTimeout(10 * 1000) // 数据传输的最长时间				.setStaleConnectionCheckEnabled(true) // 提交请求前测试连接是否可用				.build();		httpGet.setConfig(config);		httpPost.setConfig(config);		CloseableHttpResponse response = null;		try {			// 4.执行请求			response = httpclient.execute(httpGet);//            response = httpclient.execute(httpPost);									if (response.getStatusLine().getStatusCode() == 200) { // 判断返回状态是否为200				String content = EntityUtils.toString(response.getEntity(), "UTF-8");				System.out.println(content);			}			} finally {			if (response != null) {				response.close();			}			httpclient.close();		}	}}

2）使用httpClient连接池：

import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpGet;import org.apache.http.conn.HttpClientConnectionManager;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;import org.apache.http.util.EntityUtils;public class HttpClientConnectionManagerDemo {	public static void main(String[] args) throws Exception {		PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();		connectionManager.setMaxTotal(200); 			// 设置最大连接数		connectionManager.setDefaultMaxPerRoute(20); 	// 设置每个主机地址的并发数		// 执行一次get请求		doGet(connectionManager);	}	public static void doGet(HttpClientConnectionManager connectionManager) throws Exception {		CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(connectionManager).build();		String url = "http://www.jxn.com/";		HttpGet httpGet = new HttpGet(url);		CloseableHttpResponse response = null;		try {			response = httpClient.execute(httpGet);			if (response.getStatusLine().getStatusCode() == 200) {				String content = EntityUtils.toString(response.getEntity(), "UTF-8");				System.out.println(content);			}		} finally {			if (response != null) {				response.close();			}			// 此处不能关闭httpClient！如果把httpClient关闭掉，则连接池也会被销毁			// httpClient.close();		}	}}

3）HttpClient与Spring整合：

【1】pom.xml文件：


    	
     
      org.apache.httpcomponents
     	
     
      httpclient
     	
     
      4.3.5

【2】spirng配置文件applicationContext-httpclient.xml：


    
    	
     	
     
    
    
    	
     
    
    
    
    
    	
     	
     	
     	
     	
     	
     	
     	
     
    
    
    
    
    	
     
    属性配置文件httpclient.properties：	http.maxTotal=200	http.defaultMaxPerRoute=50	http.connectTimeout=1000	http.connectionRequestTimeout=500	http.socketTimeout=10000	http.staleConnectionCheckEnabled=true

【3】封装成Service：

import java.io.IOException;import java.net.URISyntaxException;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.config.RequestConfig;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.client.utils.URIBuilder;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;import org.springframework.beans.BeansException;import org.springframework.beans.factory.BeanFactory;import org.springframework.beans.factory.BeanFactoryAware;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.jxn.common.httpclient.HttpResult;[@Service](https://my.oschina.net/service)public class ApiService implements BeanFactoryAware {	private BeanFactory beanFactory;	@Autowired(required = false)	private RequestConfig requestConfig;			[@Override](https://my.oschina.net/u/1162528)	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {		this.beanFactory = beanFactory;	}	private CloseableHttpClient getHttpClient() {		return this.beanFactory.getBean(CloseableHttpClient.class);	}		// 执行GET请求	public String doGet(String url) throws ClientProtocolException, IOException {		HttpGet httpGet = new HttpGet(url);		httpGet.setConfig(requestConfig);		CloseableHttpResponse response = null;		try {			// 执行请求			response = getHttpClient().execute(httpGet);			// 判断返回状态是否为200			if (response.getStatusLine().getStatusCode() == 200) {				return EntityUtils.toString(response.getEntity(), "UTF-8");			}		} finally {			if (response != null) {				response.close();			}		}		return null;	}	// 带有参数的GET请求	public String doGet(String url, Map
    
      params) throws ClientProtocolException, IOException,			URISyntaxException {		URIBuilder builder = new URIBuilder(url);		for (Map.Entry
     
       entry : params.entrySet()) {			builder.setParameter(entry.getKey(), entry.getValue());		}		return doGet(builder.build().toString());	}	// 执行post请求	public HttpResult doPost(String url, Map
      
        params) throws IOException {		// 创建http POST请求		HttpPost httpPost = new HttpPost(url);		httpPost.setConfig(requestConfig);		if (null != params) {			List
       
         parameters = new ArrayList
        
         (0);			for (Map.Entry
         
           entry : params.entrySet()) { parameters.add(new BasicNameValuePair(entry.getKey(), entry.getValue())); } // 构造一个form表单式的实体 UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters, "UTF-8"); httpPost.setEntity(formEntity); } CloseableHttpResponse response = null; try { response = getHttpClient().execute(httpPost); return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString( response.getEntity(), "UTF-8")); } finally { if (response != null) { response.close(); } } } // 执行post请求，发送json数据 public HttpResult doPostJson(String url, String json) throws IOException { // 创建http POST请求 HttpPost httpPost = new HttpPost(url); httpPost.setConfig(requestConfig); if (null != json) { // 构造一个字符串的实体 StringEntity stringEntity = new StringEntity(json, ContentType.APPLICATION_JSON); httpPost.setEntity(stringEntity); } CloseableHttpResponse response = null; try { response = getHttpClient().execute(httpPost); return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString( response.getEntity(), "UTF-8")); } finally { if (response != null) { response.close(); } } }}// 返回的结果public class HttpResult { private Integer code; private String data; public HttpResult() { } public HttpResult(Integer code, String data) { this.code = code; this.data = data; } public Integer getCode() { return code; } public void setCode(Integer code) { this.code = code; } public String getData() { return data; } public void setData(String data) { this.data = data; }}

【4】实现定期关闭无效的连接：

import org.apache.http.conn.HttpClientConnectionManager;public class IdleConnectionEvictor extends Thread {	private final HttpClientConnectionManager connectionManager;	private volatile boolean shutdown;	// 创建IdleConnectionEvictor对象的时候，启动线程	public IdleConnectionEvictor(HttpClientConnectionManager connectionManager) {		this.connectionManager = connectionManager;		this.start();	}	[@Override](https://my.oschina.net/u/1162528)	public void run() {		try {			while (!shutdown) {				synchronized (this) {					wait(5000);					// 关闭失效的连接(每隔5秒检查一次)					connectionManager.closeExpiredConnections();				}			}		} catch (InterruptedException ex) {			// 结束		}	}	public void shutdown() {		shutdown = true;		synchronized (this) {			notifyAll();		}	}}

转载于:https://my.oschina.net/u/1399755/blog/1518325

你可能感兴趣的文章

The openssl extension is missing--composer install

查看>>

win10 系统环境变量备份

查看>>

android中string.xml串'%d'占位符的使用