一定要注意编码，请求时，content-type里的编码，仅仅是流的编码，而结果的编码类型，则是流转化为字符串是需要设定的。
以下是3种使用get/post的方式：
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.Socket; import java.net.URL; import java.net.URLConnection; import java.net.URLEncoder; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; /** * @Description:发送http请求帮助类 */ public class HttpHelper { /** * POST请求 * * @param urlStr 请求地址 * @param params 参数字典 * @param charset 编码，最好传“UTF-8” * @return * @exception RuntimeException */ public static String sendPostByHttpUrlConnection(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; // 构建请求参数 String sbParams= JoiningTogetherParams(params); HttpURLConnection con = null; OutputStreamWriter osw = null; BufferedReader br = null; // 发送请求 try { URL url = new URL(urlStr); con = (HttpURLConnection) url.openConnection(); con.setRequestMethod("POST"); con.setDoOutput(true); con.setDoInput(true); con.setUseCaches(false); con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); if (sbParams != null && sbParams.length() > 0) { osw = new OutputStreamWriter(con.getOutputStream(), charset); osw.write(sbParams); osw.flush(); } // 读取返回内容 resultBuffer = new StringBuffer(); int contentLength = Integer.parseInt(con.getHeaderField("Content-Length")); if (contentLength > 0) { br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset)); String temp; while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } } catch (Exception e) { throw new RuntimeException(e); } finally { if (osw != null) { try { osw.close(); } catch (IOException e) { osw = null; throw new RuntimeException(e); } finally { if (con != null) { con.disconnect(); con = null; } } } if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } finally { if (con != null) { con.disconnect(); con = null; } } } } return resultBuffer.toString(); } public static String sendPostByUrlConnection(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; // 构建请求参数 String sbParams= JoiningTogetherParams(params); URLConnection con = null; OutputStreamWriter osw = null; BufferedReader br = null; try { URL realUrl = new URL(urlStr); // 打开和URL之间的连接 con = realUrl.openConnection(); // 设置通用的请求属性 con.setRequestProperty("accept", "*/*"); con.setRequestProperty("connection", "Keep-Alive"); con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); con.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); // 发送POST请求必须设置如下两行 con.setDoOutput(true); con.setDoInput(true); // 获取URLConnection对象对应的输出流 osw = new OutputStreamWriter(con.getOutputStream(), charset); if (sbParams != null && sbParams.length() > 0) { // 发送请求参数 osw.write(sbParams); // flush输出流的缓冲 osw.flush(); } // 定义BufferedReader输入流来读取URL的响应 resultBuffer = new StringBuffer(); int contentLength = Integer.parseInt(con.getHeaderField("Content-Length")); if (contentLength > 0) { br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset)); String temp; while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } } catch (Exception e) { throw new RuntimeException(e); } finally { if (osw != null) { try { osw.close(); } catch (IOException e) { osw = null; throw new RuntimeException(e); } } if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } } } return resultBuffer.toString(); } public static String sendGetByHttpUrlConnection(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; // 构建请求参数 String sbParams= JoiningTogetherParams(params); HttpURLConnection con = null; BufferedReader br = null; try { URL url = null; if (sbParams != null && sbParams.length() > 0) { url = new URL(urlStr + "?" + sbParams); } else { url = new URL(urlStr); } con = (HttpURLConnection) url.openConnection(); con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); con.connect(); resultBuffer = new StringBuffer(); br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset)); String temp; while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } catch (Exception e) { throw new RuntimeException(e); } finally { if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } finally { if (con != null) { con.disconnect(); con = null; } } } } return resultBuffer.toString(); } public static String sendGetByUrlConnection(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; // 构建请求参数 String sbParams= JoiningTogetherParams(params); BufferedReader br = null; try { URL url = null; if (sbParams != null && sbParams.length() > 0) { url = new URL(urlStr + "?" + sbParams); } else { url = new URL(urlStr); } URLConnection con = url.openConnection(); // 设置请求属性 con.setRequestProperty("accept", "*/*"); con.setRequestProperty("connection", "Keep-Alive"); con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); con.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); // 建立连接 con.connect(); resultBuffer = new StringBuffer(); br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset)); String temp; while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } catch (Exception e) { throw new RuntimeException(e); } finally { if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } } } return resultBuffer.toString(); } public static String httpClientPost(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; HttpClient client = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(urlStr); // 构建请求参数 List<NameValuePair> list = new ArrayList<NameValuePair>(); Iterator<Entry<String, Object>> iterator = params.entrySet().iterator(); while (iterator.hasNext()) { Entry<String, Object> elem = iterator.next(); list.add(new BasicNameValuePair(elem.getKey(), String.valueOf(elem.getValue()))); } BufferedReader br = null; try { if (list.size() > 0) { UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset); httpPost.setEntity(entity); } HttpResponse response = client.execute(httpPost); // 读取服务器响应数据 resultBuffer = new StringBuffer(); br = new BufferedReader(new InputStreamReader(response.getEntity().getContent())); String temp; while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } catch (Exception e) { throw new RuntimeException(e); } finally { if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } } } return resultBuffer.toString(); } public static String httpClientGet(String urlStr, Map<String, Object> params, String charset) { StringBuffer resultBuffer = null; HttpClient client = new DefaultHttpClient(); BufferedReader br = null; // 构建请求参数 StringBuffer sbParams = new StringBuffer(); if (params != null && params.size() > 0) { for (Entry<String, Object> entry : params.entrySet()) { sbParams.append(entry.getKey()); sbParams.append("="); try { sbParams.append(URLEncoder.encode(String.valueOf(entry.getValue()), charset)); } catch (UnsupportedEncodingException e) { throw new RuntimeException(e); } sbParams.append("&"); } } if (sbParams != null && sbParams.length() > 0) { urlStr = urlStr + "?" + sbParams.substring(0, sbParams.length() - 1); } HttpGet httpGet = new HttpGet(urlStr); try { HttpResponse response = client.execute(httpGet); // 读取服务器响应数据 br = new BufferedReader(new InputStreamReader(response.getEntity().getContent())); String temp; resultBuffer = new StringBuffer(); while ((temp = br.readLine()) != null) { resultBuffer.append(temp); } } catch (Exception e) { throw new RuntimeException(e); } finally { if (br != null) { try { br.close(); } catch (IOException e) { br = null; throw new RuntimeException(e); } } } return resultBuffer.toString(); } public static String sendSocketPost(String urlStr, Map<String, Object> params, String charset) { String result = ""; // 构建请求参数 StringBuffer sbParams = new StringBuffer(); if (params != null && params.size() > 0) { for (Entry<String, Object> entry : params.entrySet()) { sbParams.append(entry.getKey()); sbParams.append("="); sbParams.append(entry.getValue()); sbParams.append("&"); } } Socket socket = null; OutputStreamWriter osw = null; InputStream is = null; try { URL url = new URL(urlStr); String host = url.getHost(); int port = url.getPort(); if (-1 == port) { port = 80; } String path = url.getPath(); socket = new Socket(host, port); StringBuffer sb = new StringBuffer(); sb.append("POST " + path + " HTTP/1.1 "); sb.append("Host: " + host + " "); sb.append("Connection: Keep-Alive "); sb.append("Content-Type: application/x-www-form-urlencoded; charset=utf-8 "); sb.append("Content-Length: ").append(sb.toString().getBytes().length).append(" "); // 这里一个回车换行，表示消息头写完，不然服务器会继续等待 sb.append(" "); if (sbParams != null && sbParams.length() > 0) { sb.append(sbParams.substring(0, sbParams.length() - 1)); } osw = new OutputStreamWriter(socket.getOutputStream()); osw.write(sb.toString()); osw.flush(); is = socket.getInputStream(); String line = null; // 服务器响应体数据长度 int contentLength = 0; // 读取http响应头部信息 do { line = readLine(is, 0, charset); if (line.startsWith("Content-Length")) { // 拿到响应体内容长度 contentLength = Integer.parseInt(line.split(":")[1].trim()); } // 如果遇到了一个单独的回车换行，则表示请求头结束 } while (!line.equals(" ")); // 读取出响应体数据（就是你要的数据） result = readLine(is, contentLength, charset); } catch (Exception e) { throw new RuntimeException(e); } finally { if (osw != null) { try { osw.close(); } catch (IOException e) { osw = null; throw new RuntimeException(e); } finally { if (socket != null) { try { socket.close(); } catch (IOException e) { socket = null; throw new RuntimeException(e); } } } } if (is != null) { try { is.close(); } catch (IOException e) { is = null; throw new RuntimeException(e); } finally { if (socket != null) { try { socket.close(); } catch (IOException e) { socket = null; throw new RuntimeException(e); } } } } } return result; } public static String sendSocketGet(String urlStr, Map<String, Object> params, String charset) { String result = ""; // 构建请求参数 StringBuffer sbParams = new StringBuffer(); if (params != null && params.size() > 0) { for (Entry<String, Object> entry : params.entrySet()) { sbParams.append(entry.getKey()); sbParams.append("="); sbParams.append(entry.getValue()); sbParams.append("&"); } } Socket socket = null; OutputStreamWriter osw = null; InputStream is = null; try { URL url = new URL(urlStr); String host = url.getHost(); int port = url.getPort(); if (-1 == port) { port = 80; } String path = url.getPath(); socket = new Socket(host, port); StringBuffer sb = new StringBuffer(); sb.append("GET " + path + " HTTP/1.1 "); sb.append("Host: " + host + " "); sb.append("Connection: Keep-Alive "); sb.append("Content-Type: application/x-www-form-urlencoded; charset=utf-8 "); sb.append("Content-Length: ").append(sb.toString().getBytes().length).append(" "); // 这里一个回车换行，表示消息头写完，不然服务器会继续等待 sb.append(" "); if (sbParams != null && sbParams.length() > 0) { sb.append(sbParams.substring(0, sbParams.length() - 1)); } osw = new OutputStreamWriter(socket.getOutputStream()); osw.write(sb.toString()); osw.flush(); is = socket.getInputStream(); String line = null; // 服务器响应体数据长度 int contentLength = 0; // 读取http响应头部信息 do { line = readLine(is, 0, charset); if (line.startsWith("Content-Length")) { // 拿到响应体内容长度 contentLength = Integer.parseInt(line.split(":")[1].trim()); } // 如果遇到了一个单独的回车换行，则表示请求头结束 } while (!line.equals(" ")); // 读取出响应体数据（就是你要的数据） result = readLine(is, contentLength, charset); } catch (Exception e) { throw new RuntimeException(e); } finally { if (osw != null) { try { osw.close(); } catch (IOException e) { osw = null; throw new RuntimeException(e); } finally { if (socket != null) { try { socket.close(); } catch (IOException e) { socket = null; throw new RuntimeException(e); } } } } if (is != null) { try { is.close(); } catch (IOException e) { is = null; throw new RuntimeException(e); } finally { if (socket != null) { try { socket.close(); } catch (IOException e) { socket = null; throw new RuntimeException(e); } } } } } return result; } private static String readLine(InputStream is, int contentLength, String charset) throws IOException { List<Byte> lineByte = new ArrayList<Byte>(); byte tempByte; int cumsum = 0; if (contentLength != 0) { do { tempByte = (byte) is.read(); lineByte.add(Byte.valueOf(tempByte)); cumsum++; } while (cumsum < contentLength);// cumsum等于contentLength表示已读完 } else { do { tempByte = (byte) is.read(); lineByte.add(Byte.valueOf(tempByte)); } while (tempByte != 10);// 换行符的ascii码值为10 } byte[] resutlBytes = new byte[lineByte.size()]; for (int i = 0; i < lineByte.size(); i++) { resutlBytes[i] = (lineByte.get(i)).byteValue(); } return new String(resutlBytes, charset); } private static String JoiningTogetherParams(Map<String, Object> params){ StringBuffer sbParams = new StringBuffer(); if (params != null && params.size() > 0) { for (Entry<String, Object> e : params.entrySet()) { sbParams.append(e.getKey()); sbParams.append("="); sbParams.append(e.getValue()); sbParams.append("&"); } return sbParams.substring(0, sbParams.length() - 1); } return ""; } }