JAV Language Overview

The Java language is both a compiled language and an interpreted language (compiled language: programs can leave the development environment and run independently on a particular platform. Interpreted language: Inefficient execution and easy cross-platform

JDK Directory

The Java language is a strictly case-sensitive language

Garbage collection mechanism basic principle: for objects that are no longer needed, they are no longer referenced

Characteristics:

1. Reclaim the memory space in the JVM heap memory, but not to other physical resources, such as database connection, disk I/O and other resources;

2. By setting the reference variable to NULL to imply that the garbage collection mechanism can reclaim the object;

3. The unpredictable nature of garbage collection;

4. Accuracy one: To accurately mark the Living object; two: accurately position the reference relationship between objects

5. Each recovery mechanism varies depending on the algorithm, some of which stop the application when garbage collection starts, and when garbage collection runs to allow the application's thread to run, and to allow garbage collection to run multithreaded at the same time

JAV Language Overview