http相应get和post请求示例

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) {
result += "/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);
}
}