JVM ClassLoader Architecture:

JVM ClassLoader Architecture:

A, Bootstrap classloader/Launcher class loader is primarily responsible for the core API or-xbootclasspath option specified in the Jdk_home/lib directory for the Jar wrapper into the job.

B, Extension classloader/Extension class loader is primarily responsible for the jar package in the Jdk_home/lib/ext directory or the jar wrapper in the specified directory-djava.ext.dirs the work

C, System classloader/class loader is mainly responsible for Java-classpath/-djava.class.path the directory of the class and Jar wrapper into the work.

B, user custom classloader/custom class loader (subclass of Java.lang.ClassLoader) dynamically loads class files through Java.lang.ClassLoader subclasses during program run, embodying J Ava Dynamic Real-time class loading feature.

System ClassLoader-Systems (also known as applications) ClassLoader, which is responsible for loading-classpath or Java.class.path System Properties from command Java or classpath* when the JVM is started The jar class package and classpath as specified by the System properties.

JVM ClassLoader Architecture: