HttpClient 4使用方法的几个例子

HttpClient 4使用方法的几个例子（代理,StringEntity字符串数据,文件上传）

(1) HttpClient读取页面的使用例子：

package com.laozizhu.apache.httpclient;

import java.net.Socket;

import org.apache.http.ConnectionReuseStrategy;

import org.apache.http.Header;

import org.apache.http.HttpHost;

import org.apache.http.HttpResponse;

import org.apache.http.HttpVersion;

import org.apache.http.impl.DefaultConnectionReuseStrategy;

import org.apache.http.impl.DefaultHttpClientConnection;

import org.apache.http.message.BasicHttpRequest;

import org.apache.http.params.BasicHttpParams;

import org.apache.http.params.HttpParams;

import org.apache.http.params.HttpProtocolParams;

import org.apache.http.protocol.BasicHttpContext;

import org.apache.http.protocol.BasicHttpProcessor;

import org.apache.http.protocol.ExecutionContext;

import org.apache.http.protocol.HttpContext;

import org.apache.http.protocol.HttpRequestExecutor;

import org.apache.http.protocol.RequestConnControl;

import org.apache.http.protocol.RequestContent;

import org.apache.http.protocol.RequestExpectContinue;

import org.apache.http.protocol.RequestTargetHost;

import org.apache.http.protocol.RequestUserAgent;

import org.apache.http.util.EntityUtils;

public class HttpGet {

public static void main(String[] args) throws Exception {

HttpParams params = new BasicHttpParams();

// HTTP 协议的版本,1.1/1.0/0.9

HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);

// 字符集

HttpProtocolParams.setContentCharset(params, "UTF-8");

// 伪装的浏览器类型

// IE7 是

// Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 6.0)

//

// Firefox3.03

// Mozilla/5.0 (Windows; U; Windows NT 5.2; zh-CN; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3

//

HttpProtocolParams.setUserAgent(params, "HttpComponents/1.1");

HttpProtocolParams.setUseExpectContinue(params, true);

BasicHttpProcessor httpproc = new BasicHttpProcessor();

httpproc.addInterceptor(new RequestContent());

httpproc.addInterceptor(new RequestTargetHost());

httpproc.addInterceptor(new RequestConnControl());

httpproc.addInterceptor(new RequestUserAgent());

httpproc.addInterceptor(new RequestExpectContinue());

HttpRequestExecutor httpexecutor = new HttpRequestExecutor();

HttpContext context = new BasicHttpContext(null);

HttpHost host = new HttpHost("www.java2000.net", 80);

DefaultHttpClientConnection conn = new DefaultHttpClientConnection();

ConnectionReuseStrategy connStrategy = new DefaultConnectionReuseStrategy();

context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);

context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, host);

try {

String[] targets = { "/", "/help.jsp" };

for (int i = 0; i < targets.length; i++) {

if (!conn.isOpen()) {

Socket socket = new Socket(host.getHostName(), host.getPort());

conn.bind(socket, params);

}

BasicHttpRequest request = new BasicHttpRequest("GET", targets[i]);

System.out.println(">> Request URI: " + request.getRequestLine().getUri());

context.setAttribute(ExecutionContext.HTTP_REQUEST, request);

request.setParams(params);

httpexecutor.preProcess(request, httpproc, context);

HttpResponse response = httpexecutor.execute(request, conn, context);

response.setParams(params);

httpexecutor.postProcess(response, httpproc, context);

// 返回码

System.out.println("<< Response: " + response.getStatusLine());

// 返回的文件头信息

Header[] hs = response.getAllHeaders();

for (Header h : hs) {

System.out.println(h.getName() + ":" + h.getValue());

}

// 输出主体信息

System.out.println(EntityUtils.toString(response.getEntity()));

System.out.println("==============");

if (!connStrategy.keepAlive(response, context)) {

conn.close();

} else {

System.out.println("Connection kept alive...");

}

}

} finally {

conn.close();

}

}

}

(2) HttpClient 4.0通过代理访问Https的代码例子：

import java.io.BufferedReader;

import java.io.InputStreamReader;

import org.apache.http.HttpEntity;

import org.apache.http.HttpHost;

import org.apache.http.HttpResponse;

import org.apache.http.auth.AuthScope;

import org.apache.http.auth.UsernamePasswordCredentials;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.conn.params.ConnRoutePNames;

import org.apache.http.impl.client.DefaultHttpClient;

public class HttpsProxyGet {

public static void main(String[] args) throws Exception {

DefaultHttpClient httpclient = new DefaultHttpClient();

// 认证的数据

// 我这里是瞎写的，请根据实际情况填写

httpclient.getCredentialsProvider().setCredentials(new AuthScope("10.60.8.20", 8080),

new UsernamePasswordCredentials("username", "password"));

// 访问的目标站点，端口和协议

HttpHost targetHost = new HttpHost("www.google.com", 443, "https");

// 代理的设置

HttpHost proxy = new HttpHost("10.60.8.20", 8080);

httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

// 目标地址

HttpGet httpget = new HttpGet("/adsense/login/zh_CN/?");

System.out.println("目标: " + targetHost);

System.out.println("请求: " + httpget.getRequestLine());

System.out.println("代理: " + proxy);

// 执行

HttpResponse response = httpclient.execute(targetHost, httpget);

HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (entity != null) {

System.out.println("Response content length: " + entity.getContentLength());

}

// 显示结果

BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));

String line = null;

while ((line = reader.readLine()) != null) {

System.out.println(line);

}

if (entity != null) {

entity.consumeContent();

}

}

}

(3) HttpClient使用GET方式通过代理服务器读取页面的例子:

import java.io.BufferedReader;

import java.io.InputStreamReader;

import org.apache.http.HttpEntity;

import org.apache.http.HttpHost;

import org.apache.http.HttpResponse;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.conn.params.ConnRoutePNames;

import org.apache.http.impl.client.DefaultHttpClient;

public class HttpClientGet {

public static void main(String[] args) throws Exception {

DefaultHttpClient httpclient = new DefaultHttpClient();

// 访问的目标站点，端口和协议

HttpHost targetHost = new HttpHost("www.java2000.net");

// 代理的设置

HttpHost proxy = new HttpHost("10.60.8.20", 8080);

httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

// 目标地址

HttpGet httpget = new HttpGet("/");

System.out.println("目标: " + targetHost);

System.out.println("请求: " + httpget.getRequestLine());

// 执行

HttpResponse response = httpclient.execute(targetHost, httpget);

HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (entity != null) {

System.out.println("Response content length: " + entity.getContentLength());

}

// 显示结果

BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));

String line = null;

while ((line = reader.readLine()) != null) {

System.out.println(line);

}

if (entity != null) {

entity.consumeContent();

}

}

}

(4)HttpClient 4 使用POST方式提交普通表单数据的例子:

import java.io.BufferedReader;

import java.io.InputStreamReader;

import org.apache.http.HttpEntity;

import org.apache.http.HttpHost;

import org.apache.http.HttpResponse;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.conn.params.ConnRoutePNames;

import org.apache.http.entity.StringEntity;

import org.apache.http.impl.client.DefaultHttpClient;

public class HttpClientPost {

public static void main(String[] args) throws Exception {

DefaultHttpClient httpclient = new DefaultHttpClient();

// 代理的设置

HttpHost proxy = new HttpHost("10.60.8.20", 8080);

httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

// 目标地址

HttpPost httppost = new HttpPost("http://www.java2000.net/login.jsp");

System.out.println("请求: " + httppost.getRequestLine());

// 构造最简单的字符串数据

StringEntity reqEntity = new StringEntity("username=test&password=test");

// 设置类型

reqEntity.setContentType("application/x-www-form-urlencoded");

// 设置请求的数据

httppost.setEntity(reqEntity);

// 执行

HttpResponse response = httpclient.execute(httppost);

HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (entity != null) {

System.out.println("Response content length: " + entity.getContentLength());

}

// 显示结果

BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));

String line = null;

while ((line = reader.readLine()) != null) {

System.out.println(line);

}

if (entity != null) {

entity.consumeContent();

}

}

}

(5)HttpClient 4处理文件上传的例子(MultipartEntity):

import java.io.File;

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.client.HttpClient;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.entity.mime.MultipartEntity;

import org.apache.http.entity.mime.content.FileBody;

import org.apache.http.entity.mime.content.StringBody;

import org.apache.http.impl.client.DefaultHttpClient;

public class HttpClientMultipartFormPost {

public static void main(String[] args) throws Exception {

HttpClient httpclient = new DefaultHttpClient();

HttpPost httppost = new HttpPost("http://localhost");

// 一个本地的文件

FileBody bin = new FileBody(new File("d:/BIMG1181.JPG"));

// 一个字符串

StringBody comment = new StringBody("A binary file of some kind");

// 多部分的实体

MultipartEntity reqEntity = new MultipartEntity();

// 增加

reqEntity.addPart("bin", bin);

reqEntity.addPart("comment", comment);

// 设置

httppost.setEntity(reqEntity);

System.out.println("执行: " + httppost.getRequestLine());

HttpResponse response = httpclient.execute(httppost);

HttpEntity resEntity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (resEntity != null) {

System.out.println("返回长度: " + resEntity.getContentLength());

}

if (resEntity != null) {

resEntity.consumeContent();

}

}

}

(6) httpclient中文乱码解决:

httpclient默认使用ISO-8859-1读取http响应的内容，如果内容中包含汉字的话就得动用丑陋的new String(str.getBytes("ISO-8859-1"),"GBK");语句了。

解决办法就是使用以下配置。

private static final String CONTENT_CHARSET = "GBK";// httpclient读取内容时使用的字符集

HttpClient client = new HttpClient();

client.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, CONTENT_CHARSET)