在JAVA中使用HttpURLConnection发送POST请求

public static String sendPost(String url, String param) {
OutputStreamWriter out = null;
BufferedReader in = null;
String result = "";
try {
//url为第三方接口
URL realUrl = new URL(url);
HttpURLConnection conn = null;
// 发送POST请求必须设置如下两行
conn = (HttpURLConnection) realUrl.openConnection(); // 打开和URL之间的连接
// 发送POST请求必须设置如下两行
conn.setRequestMethod("POST"); // POST方法
conn.setDoOutput(true);
conn.setDoInput(true);
// 设置通用的请求属性(这里的属性要根据第三方系统来设置)
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/json");
conn.connect();
out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8"); // 获取URLConnection对象对应的输出流
out.write(param); // param为发送请求参数
out.flush(); // flush输出流的缓冲
in=new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));// 定义BufferedReader输入流来读取URL的响应
String line;
while ((line = in.readLine()) != null) {
result += line;
System.out.println("OK");
}
} 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;
}