Java发送post方法详解

总结一下java使用http发送post的方法：

1、post请求用于发送json 格式的参数：

  public static String doPost(String url, String params) throws Exception {
 
    CloseableHttpClient httpclient = HttpClients.createDefault();
    HttpPost httpPost = new HttpPost( url );// 创建httpPost
    httpPost.setHeader( "Accept", "application/json" );
    httpPost.setHeader( "Content-Type", "application/json" );
    String charSet = "UTF-8";
    StringEntity entity = new StringEntity( params, charSet );
    httpPost.setEntity( entity );
    CloseableHttpResponse response = null;
 
    try {
 
      response = httpclient.execute( httpPost );
      StatusLine status = response.getStatusLine();
      int state = status.getStatusCode();
      if (state == HttpStatus.SC_OK) {
 HttpEntity responseEntity = response.getEntity();
 String jsonString = EntityUtils.toString( responseEntity );
 return jsonString;
      } else {
 logger.error( "请求返回:" + state + "(" + url + ")" );
      }
    } finally {
      if (response != null) {
 try {
   response.close();
 } catch (IOException e) {
   e.printStackTrace();
 }
      }
      try {
 httpclient.close();
      } catch (IOException e) {
 e.printStackTrace();
      }
    }
    return null;
  }

2、用于发送key-value格式的参数

  public static String doPost(String url, Map params) {
 
    BufferedReader in = null;
    try {
      // 定义HttpClient
      HttpClient client = new DefaultHttpClient();
      // 实例化HTTP方法
      HttpPost request = new HttpPost();
      request.setURI( new URI( url ) );
 
      //设置参数
      List nvps = new ArrayList();
      for (Iterator iter = params.keySet().iterator(); iter.hasNext(); ) {
 String name = (String) iter.next();
 String value = String.valueOf( params.get( name ) );
 nvps.add( new BasicNamevaluePair( name, value ) );
 
 //System.out.println(name +"-"+value);
      }
      request.setEntity( new UrlEncodedFormEntity( nvps, HTTP.UTF_8 ) );
 
      HttpResponse response = client.execute( request );
      int code = response.getStatusLine().getStatusCode();
      if (code == 200) {  //请求成功
 in = new BufferedReader( new InputStreamReader( response.getEntity()
     .getContent(), "utf-8" ) );
 StringBuffer sb = new StringBuffer( "" );
 String line = "";
 String NL = System.getProperty( "line.separator" );
 while ((line = in.readLine()) != null) {
   sb.append( line + NL );
 }
 in.close();
 
 return sb.toString();
      } else {  //
 System.out.println( "状态码：" + code );
 return null;
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }

第三，发送get请求

  public static String doGet(String url) {
    try {
      HttpClient client = new DefaultHttpClient();
      //发送get请求
      HttpGet request = new HttpGet( url );
      HttpResponse response = client.execute( request );
      
      if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
 
 String strResult = EntityUtils.toString( response.getEntity() );
 return strResult;
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
 
    return null;
  }

以上所述是小编给大家介绍的Java发送post方法详解整合，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对考高分网网站的支持！