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：

/**
   * post请求（用于请求json格式的参数）
   *
   * @param url  地址
   * @param params json格式的参数
   * @return
   */
  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

/**
   * post请求(用于key-value格式的参数)
   *
   * @param url
   * @param params
   * @return
   */
  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<namevaluepair> nvps = new arraylist<namevaluepair>();
      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

/**
   * get请求
   *
   * @return
   */
  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 );
      /**请求发送成功，并得到响应**/
      if (response.getstatusline().getstatuscode() == httpstatus.sc_ok) {
        /**读取服务器返回过来的json字符串数据**/
        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