How to share Java thread variables?

In Java, sharing thread variables can be achieved in the following ways:

1. Using shared objects: Multiple threads share the same object and achieve sharing by modifying the variables within the object. It is important to be mindful of thread safety issues when using this method, and synchronized keyword or Lock object can be used to protect the access to shared objects.
2. Using static variables: Static variables belong to the class, so multiple threads can directly access and modify the value of static variables. However, it is important to be cautious of thread safety issues. You can use the synchronized keyword or volatile keyword to ensure the visibility and consistency of static variables.
3. Using the ThreadLocal class: The ThreadLocal class allows for localizing thread variables, meaning each thread has its own copy of the variable. This helps avoid thread safety issues, but it’s important to remember to promptly clear the ThreadLocal variable after use to prevent memory leaks.

It is necessary to select the appropriate method to achieve the sharing of thread variables based on the specific scenario and requirements.