HTTP访问的两种方式（HttpClient和HttpURLConnection)

使用HttpClient：

NameValuePair nameValuePair1 = new BasicNameValuePair("name", "yang");
NameValuePair nameValuePair2 = new BasicNameValuePair("pwd","123123");
List nameValuePairs = new ArrayList();
nameValuePairs.add(nameValuePair1);
nameValuePairs.add(nameValuePair2);
String validateURL = "http://10.0.2.2:8080/testhttp1/TestServlet";

try {

HttpParams httpParams = new BasicHttpParams();

HttpConnectionParams.setConnectionTimeout(httpParams,5000);//设置连接超时为5秒

HttpClient client = new DefaultHttpClient(httpParams);// 生成一个http客户端发送请求对象

HttpPost httpPost = new HttpPost(urlString);//设定请求方式

  if (nameValuePairs!=null && nameValuePairs.size()!=0) {
  //把键值对进行编码操作并放入HttpEntity对象中
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8));
  }

HttpResponse httpResponse = client.execute(httpPost);// 发送请求并等待响应

// 判断网络连接是否成功
  if (httpResponse.getStatusLine().getStatusCode() != 200) {
System.out.println("网络错误异常！!!!");

return false;
}

HttpEntity entity = httpResponse.getEntity(); // 获取响应里面的内容
inputStream = entity.getContent();  // 得到服务气端发回的响应的内容（都在一个流里面）
// 得到服务气端发回的响应的内容（都在一个字符串里面）
// String strResult = EntityUtils.toString(entity);

} catch (Exception e) {
System.out.println("这是异常！");
}

使用HttpURLConnection：

String validateURL="http://10.0.2.2:8080/testhttp1/TestServlet?name=yang&pwd=123123";

try {

URL url = new URL(validateUrl); //创建URL对象

//返回一个URLConnection对象，它表示到URL所引用的远程对象的连接

HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setConnectTimeout(5000); //设置连接超时为5秒

conn.setRequestMethod("GET"); //设定请求方式

conn.connect(); //建立到远程对象的实际连接

//返回打开连接读取的输入流

DataInputStream dis = new DataInputStream(conn.getInputStream());

  //判断是否正常响应数据

if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
System.out.println("网络错误异常！!!!");

return false;
}

} catch (Exception e) {
e.printStackTrace();
  System.out.println("这是异常！");
} finally {
  if (conn != null) {
  conn.disconnect(); //中断连接
}
}