向Web站点发送GET请求、POST请求

public class TestGetPost
{
/**
* 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
*/
public static String sendGet(String url , String param)
{
String result = "";
BufferedReader in = null;
try
{
String urlName = url + "?" + param;
URL realUrl = new URL(urlName);
//打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
//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)");
//建立实际的连接
conn.connect();
//获取所有响应头字段
Map<String, List<String>> map = conn.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(conn.getInputStream()));
String line;
while ((line = in.readLine())!= null)
{
esult += "n" + 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 (IOException ex)
{
ex.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。
* @return URL所代表远程资源的响应
*/
public static String sendPost(String url,String param)
{
PrintWriter out = null;
BufferedReader in = null;
String result = "";
try
{
URL realUrl = new URL(url);
//打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
//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)");
//发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
// 获取URLConnection对象对应的输出流
out = new PrintWriter(conn.getOutputStream());
//发送请求参数
out.print(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 += "n" + 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;
}
//提供主方法，测试发送GET请求和POST请求
public static void main(String args[])
{
//发送GET请求
String s = TestGetPost.sendGet("http://localhost:8888/abc/
login.jsp",null);
System.out.println(s);
// 发送POST请求
String s1 = TestGetPost.sendPost("http://localhost:8888/abc/a.jsp",
"user= 李刚&pass=abc");
System.out.println(s1);
}
}