随笔分类 -  Java

摘要：Interface separates what a Class does and how does it work. List interface lets different type of List to implement its own method. interface has more 阅读全文

摘要：static class is used to when you don't need to instantiate the class. Like Math class, instantiating it is unnecessary. Final class prevents extension 阅读全文

摘要：如果两个对象调用equals返回相等，那么这两个对象调用hashCode方法必须返回相同的整数。如果不重写hashCode，会违反该原则。这个原则主要针对的是映射操作（map接口）。 注意： 1. String重写了Object的equals，现在比较的是两个String所包含的char seque 阅读全文

摘要：Prior to Java 5, there are a lot of casting in collections, since in collection you add objects and cast the object you get back from collection. Prov 阅读全文

摘要：Internally, both classes use array. Vector by default double the array size when array is full, while ArrayList increases the array size by 50%.Vector... 阅读全文