HttpClient发送HTTP请求详解

1.发送HTTP POST请求的例子

使用说明:需要使用httpclient-4.5.2.jar(4.3版本及以下的不适用于本例)和httpcore-4.4.4.jar。详解见注释内容。

package httpclient;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.ProtocolVersion;
import org.apache.http.StatusLine;
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.HttpPost;
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 {
	
	/**
	 * @Title:  sendPost
	 * @Description: TODO 发送一个Post请求
	 * @Attention: HttpClients.createDefault()获取的httpclient对象缺乏自定义
	 * 			一些方法不能用，比如设置CookieStore，比如设置代理的用户名密码等,这些都需要自定义而default情况下没有
	 * @param 
	 * @return void
	 * @throws 
	 * @author lzh
	 * @date 2017年7月6日 上午6:39:09
	 */
	public static void sendPost(){
		//1.建立HttpClient默认对象
		CloseableHttpClient httpclient = HttpClients.createDefault();
			//1.1另外一种方法,HttpClientBuider可以统一设置请求属性,而不再针对某个htppclient设置属性
			//HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
			//CloseableHttpClient httpclient1 = httpClientBuilder.build();
			//1.2另外一种方法，HttpClients-->HttpClientBuilder-->自定义-->生成HttpClient
			/*有用户名密码的代理设置*/
			//创建认证，并设置认证范围
			//CredentialsProvider credsProvider = new BasicCredentialsProvider();
			//credsProvider.setCredentials(new AuthScope("172.16.0.5", 80),//可以访问的范围
            //       new UsernamePasswordCredentials("MyUserName", "MyPassWord"));//用户名和密码
			//CloseableHttpClient httpclient2 = HttpClients.custom().setDefaultCredentialsProvider(credsProvider).build();
		//2.创建post请求
		HttpPost postRequest = new HttpPost("http://localhost:8080/ZT/aaa.demo");
			//2.1设置请求属性(代理，连接时间，响应时间等等)
			//HttpHost proxy = new HttpHost("172.16.0.5",80,"http");
			
				/*这种设置方法是httpclient4.5版本的，4.3的设置方法不同*/
			RequestConfig requestConfig = RequestConfig.custom()    
		        .setConnectTimeout(5000)//连接超时
		        .setConnectionRequestTimeout(1000) //响应超时   
		        .setSocketTimeout(5000)
		        //.setProxy(proxy)//设置代理
		        .build();
			postRequest.setConfig(requestConfig);
			//2.2设置请求头
				//2.2.1设置协议版本"HTTP/1.1",非常严格,HTTP必须大写
				ProtocolVersion pv = new ProtocolVersion("HTTP",1,1);
				postRequest.setProtocolVersion(pv);
				//2.2.2添加消息头
				postRequest.addHeader(HttpHeaders.ACCEPT, "text/html");
				postRequest.addHeader(HttpHeaders.CONTENT_TYPE, "application/x-www-form-urlencoded");
				postRequest.addHeader(HttpHeaders.USER_AGENT, "httpclient/4.5.2(java(1.7.0_71))");
				//2.2.3添加cookie(由于是默认直接获得的httpclient只能手动添加)
				postRequest.addHeader("Cookie","aaa=111;bbb=222");
				//2.2.4处理session(session是放在cookie里的)!!!如何设置cookie的过期时间！！！？？？
				postRequest.addHeader("Cookie", "aaa=111;JSESSIONID=E3E2I0Y7R3R3R334EANM6394");
				
		//3.创建参数列表
		List  params = new ArrayList();
		params.add(new BasicNameValuePair("parma","111"));
		//4.创建UrlEntity,方便设置编码
		UrlEncodedFormEntity uefEntity = null;
		try {
			uefEntity = new UrlEncodedFormEntity(params, "UTF-8");
			postRequest.setEntity(uefEntity);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		
		//------------------打桩打桩-----------------------------
		System.out.println("请求行:"+postRequest.getRequestLine());
		Header [] header = postRequest.getAllHeaders();
		StringBuilder sb = new StringBuilder();
		for(int i=0;i

2.发送HTTP上传文件请求

使用说明:需要使用httpclient-4.5.2.jar(4.3版本及以下的不适用于本例)和httpcore-4.4.4.jar以及httpmime-4.5.2。详解见注释内容。

package httpclient;

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

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.ProtocolVersion;
import org.apache.http.StatusLine;
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.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
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;

/**
 * @Title: PostFileUpload 
 * @Description: 文件上传的例子
 * @author lzh
 * @date 2017年7月6日 下午6:34:48
 */
public class PostFileUpload {

	public static String postUrl = "http://localhost:8080/springMVCfileUpload/filesUpload.j";
	public static String postUrl2 = "http://localhost:8080/ZT/aaa.demo";
	
	
	
	/**
	 * @Title:  sendPost
	 * @Description: TODO 发送一个Post请求进行文件上传
	 * @Attention: HttpClients.createDefault()获取的httpclient对象缺乏自定义
	 * 			一些方法不能用，比如设置CookieStore，比如设置代理的用户名密码等,这些都需要自定义而default情况下没有
	 * @param 
	 * @return void
	 * @throws 
	 * @author lzh
	 * @date 2017年7月6日 上午6:39:09
	 */
	public static void sendPost(){
		//1.建立HttpClient默认对象
		CloseableHttpClient httpclient = HttpClients.createDefault();
			//1.1另外一种方法,HttpClientBuider可以统一设置请求属性,而不再针对某个htppclient设置属性
			//HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
			//CloseableHttpClient httpclient1 = httpClientBuilder.build();
			//1.2另外一种方法，HttpClients-->HttpClientBuilder-->自定义-->生成HttpClient
			/*有用户名密码的代理设置*/
			//创建认证，并设置认证范围
			//CredentialsProvider credsProvider = new BasicCredentialsProvider();
			//credsProvider.setCredentials(new AuthScope("172.16.0.5", 80),//可以访问的范围
            //       new UsernamePasswordCredentials("MyUserName", "MyPassWord"));//用户名和密码
			//CloseableHttpClient httpclient2 = HttpClients.custom().setDefaultCredentialsProvider(credsProvider).build();
		//2.创建post请求
		HttpPost postRequest = new HttpPost(postUrl2);
			//2.1设置请求属性(代理，连接时间，响应时间等等)
			//HttpHost proxy = new HttpHost("172.16.0.5",80,"http");
			
				/*这种设置方法是httpclient4.5版本的，4.3的设置方法不同*/
			RequestConfig requestConfig = RequestConfig.custom()    
		        .setConnectTimeout(5000)//连接超时
		        .setConnectionRequestTimeout(1000) //响应超时   
		        .setSocketTimeout(5000)
		        //.setProxy(proxy)//设置代理
		        .build();
			postRequest.setConfig(requestConfig);
			//2.2设置请求头
				//2.2.1设置协议版本"HTTP/1.1",非常严格,HTTP必须大写
				ProtocolVersion pv = new ProtocolVersion("HTTP",1,0);
				postRequest.setProtocolVersion(pv);
				//2.2.2添加消息头
				postRequest.addHeader(HttpHeaders.ACCEPT, "text/html");
				//postRequest.addHeader(HttpHeaders.CONTENT_TYPE, "application/x-www-form-urlencoded");
				postRequest.addHeader(HttpHeaders.USER_AGENT, "httpclient/4.5.2(java(1.7.0_71))");
				//2.2.3添加cookie(由于是默认方式获得的httpclient只能手动添加,不能用CookieStore自动添加)
				postRequest.addHeader("Cookie","aaa=111;bbb=222");
				//2.2.4处理session(session是放在cookie里的)!!!如何设置cookie的过期时间！！！？？？
				postRequest.addHeader("Cookie", "aaa=111;JSESSIONID=E3E2I0Y7R3R3R334EANM6394");
				
		//3.创建参数列表
		List  params = new ArrayList();
		params.add(new BasicNameValuePair("parma","111"));
		//4.创建文件上传Entity,方便设置编码
		//UrlEncodedFormEntity uefEntity = null;
		//4.1创建builder对象
		MultipartEntityBuilder meb = MultipartEntityBuilder.create().setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
		//决定content-type消息头中charset的值
		meb.setCharset(Charset.forName("utf-8"));
		//决定content-type消息头中boundary的值(这个值用来分隔不同文件与字段,一般浏览器是随机生成的)
		meb.setBoundary(UUID.randomUUID().toString().replaceAll("-", "")+"haha");
		//表单普通字段
		meb.addPart("param1",new StringBody("外流1",ContentType.create("text/plain", "UTF-8")));
		meb.addPart("param2",new StringBody("第二个",ContentType.create("text/plain", "UTF-8")));
		//表单文件字段
		File file1 = new File("E://要哭.gif");
		File file2 = new File("F://LOLCfg.ini");
		//服务端用utf-8解析报文，不会中文乱码(一般服务端都要加Spring的那个编码过滤器)
		meb.addPart("files", new FileBody(file1,ContentType.MULTIPART_FORM_DATA,"要哭.gif"));
		//new FileBody(file, contentType, filename)
		meb.addPart("files", new FileBody(file2));
		HttpEntity he = meb.build();
		//uefEntity = new UrlEncodedFormEntity(params, "UTF-8");
		postRequest.setEntity(he);
		
		//------------------打桩打桩-----------------------------
		System.out.println("请求行:"+postRequest.getRequestLine());
		Header [] header = postRequest.getAllHeaders();
		StringBuilder sb = new StringBuilder();
		for(int i=0;i

代码的异常处理是不规范的，但是这毕竟只是demo，方便学习，知道哪里会抛哪些异常就可以了。