java调用第三方接口

/**
 * 向指定URL发送POST请求
 * 
 * @param url
 * @param postParam
 * @return
 * @return 响应结果
 */
public String sendPost(String url, String postParam) throws IOException {
	Map paramMap = new HashMap();
	postParam=URLEncoder.encode(postParam, "UTF-8");
	paramMap.put("param", postParam);

	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/5.0 (Windows NT 10.0; Win64; x64)");
		conn.setRequestProperty("Charset", "UTF-8");
		// 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());

		// 设置请求属性
		String param = "";
		if (paramMap != null && paramMap.size() > 0) {
			Iterator ite = paramMap.keySet().iterator();
			while (ite.hasNext()) {
				String key = ite.next();// key
				String value = paramMap.get(key);
				param += key + "=" + value + "&";
			}
			param = param.substring(0, param.length() - 1);
		}

		// 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 += 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;
}