javaHTTP请求工具类-使用HttpURLConnection实现

package zmx.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

/**
* Http请求工具类
*
*/
public class HttpRequestUtil {
static boolean proxySet = false;
static String proxyHost = "127.0.0.1";
static int proxyPort = 8087;
/**
* 编码
* @param source
* @return
*/
public static String urlEncode(String source,String encode) {
String result = source;
try {
result = java.net.URLEncoder.encode(source,encode);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return "0";
}
return result;
}

public static String urlEncodeGBK(String source) {
String result = source;
try {
result = java.net.URLEncoder.encode(source,"GBK");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return "0";
}
return result;
}
/**
* 发起http请求获取返回结果
* @param req_url 请求地址
* @return
*/
public static String httpRequest(String req_url) {
StringBuffer buffer = new StringBuffer();
try {
URL url = new URL(req_url);
HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();

httpUrlConn.setDoOutput(true);
httpUrlConn.setDoInput(true);
httpUrlConn.setUseCaches(false);
httpUrlConn.setConnectTimeout(50000);
httpUrlConn.setReadTimeout(50000);
httpUrlConn.setRequestMethod("GET");
// httpUrlConn.setRequestProperty("Accept", "image/png,image/*;q=0.8,*/*;q=0.5");
// httpUrlConn.setRequestProperty("Accept-Encoding", "gzip");
//httpUrlConn.setRequestProperty("Referer", "http://www.hao123.com/");
httpUrlConn.connect();  //发送请求
if (httpUrlConn.getResponseCode() == 200) {

// 将返回的输入流转换成字符串
InputStream inputStream = httpUrlConn.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

String str = null;
while ((str = bufferedReader.readLine()) != null) {
buffer.append(str);
}
bufferedReader.close();
inputStreamReader.close();
// 释放资源
inputStream.close();
inputStream = null;
httpUrlConn.disconnect();

}

} catch (Exception e) {
System.out.println(e.getStackTrace());
}
return buffer.toString();
}

/**
* 发送http请求取得返回的输入流
* @param requestUrl 请求地址
* @return InputStream
*/
public static InputStream httpRequestIO(String requestUrl) {
InputStream inputStream = null;
try {
URL url = new URL(requestUrl);
HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();
httpUrlConn.setDoInput(true);
httpUrlConn.setRequestMethod("GET");
httpUrlConn.connect();
// 获得返回的输入流
inputStream = httpUrlConn.getInputStream();
} catch (Exception e) {
e.printStackTrace();
}
return inputStream;
}

/**
* 向指定URL发送GET方法的请求
*
* @param url
*            发送请求的URL
* @param param
*            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @return URL 所代表远程资源的响应结果
*/
public static String sendGet(String url, String param) {
String result = "";
BufferedReader in = null;
try {
String urlNameString = url + "?" + param;
URL realUrl = new URL(urlNameString);
// 打开和URL之间的连接
URLConnection connection = realUrl.openConnection();
// 设置通用的请求属性
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 建立实际的连接
connection.connect();
// 获取所有响应头字段
Map<String, List<String>> map = connection.getHeaderFields();
// 遍历所有的响应头字段
for (String key : map.keySet()) {
System.out.println(key + "--->" + map.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送GET请求出现异常！" + e);
e.printStackTrace();
}
// 使用finally块来关闭输入流
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return result;
}

/**
* 向指定 URL 发送POST方法的请求
*
* @param url
*            发送请求的 URL
* @param param
*            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @param isproxy
*               是否使用代理模式
* @return 所代表远程资源的响应结果
*/
public static String sendPost(String url, String param,boolean isproxy) {
OutputStreamWriter out = null;
BufferedReader in = null;
String result = "";
try {
URL realUrl = new URL(url);
HttpURLConnection conn = null;
if(isproxy){//使用代理模式
@SuppressWarnings("static-access")
Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));
conn = (HttpURLConnection) realUrl.openConnection(proxy);
}else{
conn = (HttpURLConnection) realUrl.openConnection();
}
// 打开和URL之间的连接

// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestMethod("POST");    // POST方法

// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

conn.connect();

// 获取URLConnection对象对应的输出流
out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
// 发送请求参数
out.write(param);
// flush输出流的缓冲
out.flush();
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送 POST 请求出现异常！"+e);
e.printStackTrace();
}
//使用finally块来关闭输出流、输入流
finally{
try{
if(out!=null){
out.close();
}
if(in!=null){
in.close();
}
}
catch(IOException ex){
ex.printStackTrace();
}
}
return result;
}

public static void main(String[] args) {

String url = "http://www.baidu.com/s";
String para ="word=刘德华";
String sr=HttpRequestUtil.httpRequest(url);
//String sr=HttpRequestUtil.sendGet(url,para);
System.out.println(sr);

//demo:代理访问
//String sr=HttpRequestUtil.sendPost(url,para,true);
//System.out.println(sr);
}

}