ObjectInputStream 與 ObjectOutputStream

      用Socket通訊的時候如果要用到ObjectInputStream 與 ObjectOutputStream的話，要確保Server端與Client端ObjectInputStream 與 ObjectOutputStream產生的順序。

      在Server（Client）端產生一個ObjectInputStream流時必須確保在Client（Server）端產生一個ObjectOutputStream流。

      根據上述原則，合法的可能產生順序有

      1、

            Server                          Client

            ObjectInputStream      ObjectOutputStream

            ObjectOutputStream    ObjectInputStream

 

      2、

            Server                          Client

            ObjectOutputStream    ObjectInputStream

            ObjectInputStream      ObjectOutputStream

 

     其他情況都會引起阻塞。

 

    引用：

           public ObjectInputStream(InputStream in) throws IOException

Creates an ObjectInputStream that reads from the specified InputStream.
A serialization stream header is read from the stream and verified.
This constructor will block until the corresponding ObjectOutputStream
has written and flushed the header.

If a security manager is installed, this constructor will check for
the "enableSubclassImplementation" SerializablePermission when invoked
directly or indirectly by the constructor of a subclass which overrides
the ObjectInputStream.readFields or ObjectInputStream.readUnshared
methods.