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;

/**
* HttpClient使用GET方式通過代理服務器讀取頁面的例子。
*
* @author JAVA世紀網(java2000.net, laozizhu.com)
*/
public class HttpClientGet {
public static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
// 訪問的目標站點，端口和協議
HttpHost targetHost = new HttpHost("www.java2000.net");
// 代理的設置
HttpHost proxy = new HttpHost("10.60.8.20", 8080);
httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
// 目標地址
HttpGet httpget = new HttpGet("/");
System.out.println("目標: " + targetHost);
System.out.println("請求: " + httpget.getRequestLine());
// 執行
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());
}
// 顯示結果
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();
}
}
}

2、HttpClient 4 使用POST方式提交普通表單數據的例子

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;

/**
* HttpClient 4 使用POST方式提交普通表單數據的例子.
*
* @author JAVA世紀網(java2000.net, laozizhu.com)
*/
public class HttpClientPost {
public static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
// 代理的設置
HttpHost proxy = new HttpHost("10.60.8.20", 8080);
httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
// 目標地址
HttpPost httppost = new HttpPost("http://www.java2000.net/login.jsp");
System.out.println("請求: " + httppost.getRequestLine());
// 構造最簡單的字符串數據
StringEntity reqEntity = new StringEntity("username=test&password=test");
// 設置類型
reqEntity.setContentType("application/x-www-form-urlencoded");
// 設置請求的數據
httppost.setEntity(reqEntity);
// 執行
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());
}
// 顯示結果
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 4.0通過代理訪問Https的代碼例子

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;

/**
* HttpClient 4.0通過代理訪問Https的代碼例子。
*
* @author JAVA世紀網(java2000.net, laozizhu.com)
*/
public class HttpsProxyGet {
public static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
// 認證的數據
// 我這裏是瞎寫的，請根據實際情況填寫
httpclient.getCredentialsProvider().setCredentials(new AuthScope("10.60.8.20", 8080),
new UsernamePasswordCredentials("username", "password"));
// 訪問的目標站點，端口和協議
HttpHost targetHost = new HttpHost("www.google.com", 443, "https");
// 代理的設置
HttpHost proxy = new HttpHost("10.60.8.20", 8080);
httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
// 目標地址
HttpGet httpget = new HttpGet("/adsense/login/zh_CN/?");
System.out.println("目標: " + targetHost);
System.out.println("請求: " + httpget.getRequestLine());
System.out.println("代理: " + proxy);
// 執行
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());
}
// 顯示結果
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讀取頁面的使用例子

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;

/**
* HttpClient讀取頁面的使用例子
* @author 老紫竹(java2000.net)
*
*/
public class HttpGet {
public static void main(String[] args) throws Exception {

HttpParams params = new BasicHttpParams();
// HTTP 協議的版本,1.1/1.0/0.9
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
// 字符集
HttpProtocolParams.setContentCharset(params, "UTF-8");
// 偽裝的瀏覽器類型
// 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);

// 返回碼
System.out.println("<< Response: " + response.getStatusLine());
// 返回的文件頭信息
Header[] hs = response.getAllHeaders();
for (Header h : hs) {
System.out.println(h.getName() + ":" + h.getValue());
}
// 輸出主體信息
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();
}
}
}

5、httpclient中文亂碼解決

httpclient默認使用ISO-8859-1讀取http響應的內容，如果內容中包含漢字的話就得動用醜陋的new String(str.getBytes("ISO-8859-1"),"GBK");語句了。

解決辦法就是使用以下配置。

private static final String CONTENT_CHARSET = "GBK";// httpclient讀取內容時使用的字符集

HttpClient client = new HttpClient();
client.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, CONTENT_CHARSET);

6、HttpClient 4處理文件上傳的例子(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;

/**
* HttpClient 4處理文件上傳的例子(MultipartEntity).<br>
* 需要 James Mime4j 0.5的版本，0.6的不行。
*
* @author JAVA世紀網(java2000.net, laozizhu.com)
*/
public class HttpClientMultipartFormPost {
public static void main(String[] args) throws Exception {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://localhost");
// 一個本地的文件
FileBody bin = new FileBody(new File("d:/BIMG1181.JPG"));
// 一個字符串
StringBody comment = new StringBody("A binary file of some kind");
// 多部分的實體
MultipartEntity reqEntity = new MultipartEntity();
// 增加
reqEntity.addPart("bin", bin);
reqEntity.addPart("comment", comment);
// 設置
httppost.setEntity(reqEntity);
System.out.println("執行: " + 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("返回長度: " + resEntity.getContentLength());
}
if (resEntity != null) {
resEntity.consumeContent();
}
}
}

HttpClient使用GET方式通過代理服務器讀取頁面的例子