Understanding the 'transient' Keyword in Java

In Java, the transient keyword has a specific function when it's applied to a class field. It serves to compel the Java Virtual Machine (JVM) to skip or ignore the field when trying to serialize the object containing it. As a result, it makes the field non-serializable. In other words, when an object is being transformed into a byte stream (a process called serialization), fields marked as transient won't be included in that stream. Similarly, during the reverse process known as deserialization, these fields won't be restored with the rest of the object's state.

Practical Examples

Consider the following class:

class Employee implements Serializable {
    String name;
    transient String password;
}

In the above Employee class, if we serialize an object of the class, the name would be serialized, but the password would not because password is marked as transient.

This application is particularly useful in scenarios where storing or transmitting certain information is not required, or for security purposes. In our example, the password field of the Employee class is transient because serialization of such sensitive information may pose a security risk.

Best Practices and Additional Insights

In practice, it's recommended to use the transient keyword wisely. Before you decide to mark a field as transient, ensure that the field is indeed not necessary to be serialized. If a necessary field is marked as transient, it can lead to loss of important data.

Remember, the transient keyword does not make a field temporary or volatile. It solely determines whether a field needs to be skipped from serialization or not. In Java, volatile fields are variables read from and written to main memory instead of the CPU cache and volatile keyword is used to modify the behavior of this field.

In conclusion, the 'transient' keyword is a useful tool in Java that excels at providing more control over the serialization process, effectively increasing the security and efficiency of your Java applications.