[JAVA 介绍](Java/java_introduction.md) [JAVA 运行原理](Java/operating_principle.md) [JDK 配置](Java/jdk_configuration.md) [类和对象](Java/class_and_object.md) [数据类型](Java/data_type.md) [变量](Java/variable.md) [直接量](Java/literals.md) [运算符](Java/operator.md) [流程控制](Java/process_control.md) [数组结构](Java/data_structure.md) [面向对象](Java/oop.md) [隐藏和封装](Java/hide_and_packaging.md) [深入构造器](Java/constructor.md) [类的继承](Java/inherit.md) [多态](Java/polymorphism.md) [包装类](Java/packaging_class.md) [final 修饰符](Java/final.md) [抽象类](Java/abstract_class.md) [接口](Java/interface.md) [集合框架](Java/collections_framework.md) [常用类学习](Java/common_class.md) [异常处理](Java/exception_handling.md) [设计模式-单例模式](Java/singleton_pattern.md) [JDBC](Java/JDBC.md)