java transient

transient is a Java keyword which marks a member variable not to be serialized when it is persisted to streams of bytes. When an object is transferred through the network, the object needs to be 'serialized'. Serialization converts the object state to serial bytes. Those bytes are sent over the network and the object is recreated from those bytes. Member variables marked by the java transient keyword are not transferred, they are lost intentionally.

Syntax:

private transient <member-variable>;
or 
transient private <member-variable>;

For example:

public class Foo { private String saveMe ; private transient String dontSaveMe ; private transient String password ; //... }

 

transient关键字只能修饰变量，而不能修饰方法和类。注意，本地变量是不能被transient关键字修饰的。

被transient关键字修饰的变量不再能被序列化，一个静态变量不管是否被transient修饰，均不能被序列化。

 

对象的序列化可以通过实现两种接口来实现，若操作的是一个Serializable对象，则所有的序列化将会自动进行，若操作的是 一个Externalizable对象，则没有任何东西可以自动序列化，需要在writeExternal方法中进行手工指定所要序列化的变量，这与是否被transient修饰无关。