java模拟post请求

利用java模拟post请求，有参数，参数格式为map形式
“`java

public static void post(Integer i,String urlStr, Map parameterMap)
        throws IOException {
    URL url = new URL(urlStr);
    HttpURLConnection httpURLConnection = (HttpURLConnection) url
            .openConnection();
    httpURLConnection.setDoInput(true);
    httpURLConnection.setDoOutput(true); // 设置该连接是可以输出的
    httpURLConnection.setRequestMethod("POST"); // 设置请求方式
    httpURLConnection.setRequestProperty("charset", "utf-8");
    System.out.println(httpURLConnection.getURL().toString());
    PrintWriter pw = new PrintWriter(new BufferedOutputStream(
            httpURLConnection.getOutputStream()));
    StringBuffer parameter = new StringBuffer();
    parameter.append("1=1");
    for (Entry entry : parameterMap.entrySet()) {
        parameter.append("&" + entry.getKey() + "=" + entry.getValue());
    }
    pw.write(parameter.toString());// 向连接中写数据（相当于发送数据给服务器）
    pw.flush();
    pw.close();
    System.out.println("parameter: " + parameter.toString());
    BufferedReader br = new BufferedReader(new InputStreamReader(
            httpURLConnection.getInputStream(), "utf-8"));
    String line = null;
    StringBuilder sb = new StringBuilder();
    while ((line = br.readLine()) != null) { // 读取数据
        sb.append(line + "\n");
    }
    br.close();
    System.out.println(sb.toString());
}
```

注意：如果用gradle，需要下载个jar包

compile(‘commons-httpclient:commons-httpclient:3.0.1’)