你可以使用Socket来实现

String host = "www.yourhost.com";
Socket socket = new Socket(host, 80);
String request = "GET / HTTP/1.0\r\n\r\n";
OutputStream os = socket.getOutputStream();
os.write(request.getBytes());
os.flush();

InputStream is = socket.getInputStream();
int ch;
while( (ch=is.read())!= -1)
    System.out.print((char)ch);
socket.close();    

我知道其他人会推荐Apache的http-客户端，但是它增加了复杂性(例如，更多可能出错的东西)，这是很少被保证的。对于简单的任务，可以使用java.net.URL。

URL url = new URL("http://www.y.com/url");
InputStream is = url.openStream();
try {
  /* Now read the retrieved document from the stream. */
  ...
} finally {
  is.close();
}

来自Oracle的java教程

import java.net.*;
import java.io.*;

public class URLConnectionReader {
    public static void main(String[] args) throws Exception {
        URL yahoo = new URL("http://www.yahoo.com/");
        URLConnection yc = yahoo.openConnection();
        BufferedReader in = new BufferedReader(
                                new InputStreamReader(
                                yc.getInputStream()));
        String inputLine;

        while ((inputLine = in.readLine()) != null) 
            System.out.println(inputLine);
        in.close();
    }
}

你可以使用Socket来实现

String host = "www.yourhost.com";
Socket socket = new Socket(host, 80);
String request = "GET / HTTP/1.0\r\n\r\n";
OutputStream os = socket.getOutputStream();
os.write(request.getBytes());
os.flush();

InputStream is = socket.getInputStream();
int ch;
while( (ch=is.read())!= -1)
    System.out.print((char)ch);
socket.close();    

这里有一个通过Example Depot发送POST请求的链接::

try {
    // Construct data
    String data = URLEncoder.encode("key1", "UTF-8") + "=" + URLEncoder.encode("value1", "UTF-8");
    data += "&" + URLEncoder.encode("key2", "UTF-8") + "=" + URLEncoder.encode("value2", "UTF-8");

    // Send data
    URL url = new URL("http://hostname:80/cgi");
    URLConnection conn = url.openConnection();
    conn.setDoOutput(true);
    OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
    wr.write(data);
    wr.flush();

    // Get the response
    BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;
    while ((line = rd.readLine()) != null) {
        // Process line...
    }
    wr.close();
    rd.close();
} catch (Exception e) {
}

如果您想发送一个GET请求，您可以稍微修改代码以满足您的需要。具体来说，您必须在URL的构造函数中添加参数。然后，还注释掉这个wr.write(data);

有一件事没有写下来，你应该注意，就是超时。特别是如果你想在WebServices中使用它，你必须设置超时，否则上面的代码将无限期地等待，或者至少等待很长时间，这可能是你不想要的。

超时设置如下conn.setReadTimeout(2000);输入参数以毫秒为单位

下面是一个完整的Java 7程序:

class GETHTTPResource {
  public static void main(String[] args) throws Exception {
    try (java.util.Scanner s = new java.util.Scanner(new java.net.URL("http://example.com/").openStream())) {
      System.out.println(s.useDelimiter("\\A").next());
    }
  }
}

新的try-with-resources将自动关闭Scanner，而Scanner将自动关闭InputStream。