The choice of which overloading to invoke is made at compile time. // Broken! - What does this program print? public class CollectionClassifier { public static String classify(Set<?> s) { return "Set"; } public static String classify(List&…
Principles If you override the clone method in a nonfinal class, you should return an object obtained by invoking super.clone In practice, a class that implements Cloneable is expected to provide a properly functioning public clone method. Never make…
Implementation theory The varargs facility works by first creating an array whose size is the number of arguments passed at the call site, then putting the argument values into the array, and finally passing the array to the method. // Simple use of…
Disadvantage of Serializable A major cost of implementing Serializable is that it decreases the flexibility to change a class's implementation once it has been released. If you accept the default serialized form, the class's private and package-priva…
Hi guys, I am happy to tell you that I am moving to the open source world. And Java is the 1st language I have chosen for this migration. It's a nice chance to read some great books like "Effective Java 2nd Edition" and share the note for what I…
Chapter 7 Methods Item 38: Check parameters for validity 直接举例吧: /** * ...其他的被我省略了 * @throws ArithmeticException if m is less than or equal to 0 */ public BigInteger mod(BigInteger m) { if (m.signum() <= 0) throw new ArithmeticException("Modulus &l…
<Effective Java>目录摘抄. 我知道这看起来很糟糕.当下,自己缺少实际操作,只能暂时摘抄下目录.随着,实践的增多,慢慢填充更多的示例. Chapter 2 Creating and Destroying Objects Consider static factory methods instead of constructors Consider a builder when faced with many constructor parameters Enforce the s…
Java写了很多年,很惭愧,直到最近才读了这本经典之作<Effective Java>,按自己的理解总结下,有些可能还不够深刻 一.Creating and Destroying Objects Consider static factory methods instead of constructors (factory方法可以拥有名称,可以避免重复创建,比如单例模式) Consider a builder when faced with many constructor parameter…
