HTTP请求时connectionRequestTimeout 、connectionTimeout、socketTimeout三个超时时间的含义

connetionTimeout：指客户端和服务器建立连接的timeout，
就是http请求的三个阶段，一：建立连接；二：数据传送；三，断开连接。超时后会ConnectionTimeOutException
socketTimeout：指客户端从服务器读取数据的timeout，超出后会抛出SocketTimeOutException
[code="prettyprint"]/**
    * Returns the timeout in milliseconds used when requesting a connection
    * from the connection manager. A timeout value of zero is interpreted
    * as an infinite timeout.
    * A timeout value of zero is interpreted as an infinite timeout.
    * A negative value is interpreted as undefined (system default).
    * Default: {@code -1}
    */
   public int getConnectionRequestTimeout() { 
       return connectionRequestTimeout; 
   } 

     /**
    * Determines the timeout in milliseconds until a connection is established.
    * A timeout value of zero is interpreted as an infinite timeout.
    * A timeout value of zero is interpreted as an infinite timeout.
    * A negative value is interpreted as undefined (system default).
    * Default: {@code -1}
    */ 
   public int getConnectTimeout() { 
       return connectTimeout; 
   } 

   /**
    * Defines the socket timeout ({@code SO_TIMEOUT}) in milliseconds,
    * which is the timeout for waiting for data  or, put differently,
    * a maximum period inactivity between two consecutive data packets).
    * A timeout value of zero is interpreted as an infinite timeout.
    * A negative value is interpreted as undefined (system default).
    * Default: {@code -1}
    */ 
   public int getSocketTimeout() { 
       return socketTimeout; 
   }