java发送post请求的代码

/**
* 向指定 URL 发送POST方法的请求
* @param url 发送请求的 URL
* @param params 请求的参数集合
* @return 远程资源的响应结果
*/
@SuppressWarnings(“unused”)
private String sendPost(String url, Map<String, String> params) {
OutputStreamWriter out = null;
BufferedReader in = null;
StringBuilder result = new StringBuilder();
try {
URL realUrl = new URL(url);
HttpURLConnection conn =(HttpURLConnection) realUrl.openConnection();
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
// POST方法
conn.setRequestMethod(“POST”);
// 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)”);
conn.setRequestProperty(“Content-Type”, “application/x-www-form-urlencoded”);
conn.connect();
// 获取URLConnection对象对应的输出流
out = new OutputStreamWriter(conn.getOutputStream(), “UTF-8”);
// 发送请求参数
if (params != null) {
StringBuilder param = new StringBuilder();
for (Map.Entry<String, String> entry : params.entrySet()) {
if(param.length()>0){
param.append(“&”);
}
param.append(entry.getKey());
param.append(“=”);
param.append(entry.getValue());
//System.out.println(entry.getKey()+”:”+entry.getValue());
}
//System.out.println(“param:”+param.toString());
out.write(param.toString());
}
// 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(), “UTF-8”));
String line;
while ((line = in.readLine()) != null) {
result.append(line);
}
} catch (Exception 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.toString();
}