[01_java数据类型](01_java%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B.md) [02_java标识符](02_java%E6%A0%87%E8%AF%86%E7%AC%A6.md) [03_java面向对象思想](03_java%E9%9D%A2%E5%90%91%E5%AF%B9%E8%B1%A1%E6%80%9D%E6%83%B3.md) [04_java集合](04_java%E9%9B%86%E5%90%88.md)