Java使用HttpURLConnection调用WebService（原始方法）

说明：使用Java原生的HttpURLConnection调用WebService可以免去引入SOA的框架，比如一些CXF框架等。可以使代码足够精简，比如对于一些只调用一两个接口的，这种方式是最适合的。

package com.jsfot.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * WebServiceClient
 *
 * @author jim
 * @date 2017/12/11
 */
public class WebServiceClient {

    /**
     * 禁止实例化
     */
    private WebServiceClient() {
        throw new IllegalStateException("工具类禁止实例化");
    }

    private static final String CHARSET_NAME = "UTF-8";

    /**
     * POST请求
     *
     * @param url    请求地址
     * @param params XML字符串
     * @return null为调用失败
     */
    public static String doPost(String url, String params) {
        try {
            HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 超时时间30秒
            int timeout = 30 * 1000;
            conn.setConnectTimeout(timeout);
            conn.setReadTimeout(timeout);
            conn.connect();
            if (params != null) {
                OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream(), CHARSET_NAME);
                out.write(params);
                out.flush();
                out.close();
            }
            InputStreamReader r = new InputStreamReader(conn.getInputStream(), CHARSET_NAME);
            BufferedReader reader = new BufferedReader(r);
            String line;
            StringBuffer sb = new StringBuffer();
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            return sb.toString();
        } catch (IOException e) {
            return null;
        }
    }
}

参考：

http://blog.csdn.net/u010890857/article/details/52944729

http://blog.csdn.net/liangwenmail/article/details/51959714