JVM class loader (2)

JVM（ Two ）

ClassLoader

Here is the main record pair ClassLoader The understanding of the

A simple understanding of class loaders

ClassLoader The job of Dynamically Load the bytecode file of the class into memory , Make the program run normally .

Classification of class loaders

• Bootstrap ClassLoader： Start class loader
• Extension ClassLoader： Extend the classloader
• Application ClassLoader： system class loader
• Custom class loaders

Bootstrap ClassLoader

Concept ：
The boot class loader is created by C++ Code implemented , Is the topmost loaded class , The main role Is load Java Core class library of . %JAVA_HOME%\lib Under the rt.jar、resources.jar、class etc. .
Extension ClassLoader and Application ClassLoader It's all by Bootstrap ClassLoader Loaded .

JVM tuning
adopt -Xbootclasspath Command to modify the loaded class
-Xbootclasspath: Completely replace the basic core of Java class Search path &#