Marker interface is an interface that contains no method declarations, but merely designates (or "marks") a class that implements the interface as having some property. Such as Serializable interface which indicates that the instance implements…

The readResolve feature allows you to substitute another instance for the one created by readObject [Serialization, 3.7]. If the class of an object being deserialized defines a readResolve method with the proper declaration, this method is invoked on…

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 6 Enums and Annotations Item 30: Use enums instead of int constants Enum类型无非也是个普通的class,所以你可以给他加class能有的东西,比如constructor: public enum Planet { MERCURY(3.302e+23, 2.439e6), VENUS (4.869e+24, 6.052e6), EARTH (5.975e+24, 6.378e6): private final…

<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…

Reason The constant interface pattern is a poor use of interfaces. That a class uses some constants internally is an implementation detail. Implementing a constant interface causes this implementation detail to leak into the class's exported API. It…

Tips <Effective Java, Third Edition>一书英文版已经出版,这本书的第二版想必很多人都读过,号称Java四大名著之一,不过第二版2009年出版,到现在已经将近8年的时间,但随着Java 6,7,8,甚至9的发布,Java语言发生了深刻的变化. 在这里第一时间翻译成中文版.供大家学习分享之用. 37. 使用EnumMap替代序数索引 有时可能会看到使用ordinal方法(条目 35)来索引到数组或列表的代码. 例如,考虑一下这个简单的类来代表一种植物: class…

声明:原创作品,转载时请注明文章来自SAP师太技术博客( 博/客/园www.cnblogs.com):www.cnblogs.com/jiangzhengjun,并以超链接形式标明文章原始出处,否则将追究法律责任!原文链接:http://www.cnblogs.com/jiangzhengjun/p/4255680.html 第八章      通用程序设计 45.      将局部变量的作用域最小化 将局部变量的作用域最小化,可以增强代码的可读性和可维护性,并降低出错的可能性. 要使用局部变量的…

Effective Java通俗理解(上) 第31条:用实例域代替序数 枚举类型有一个ordinal方法,它范围该常量的序数从0开始,不建议使用这个方法,因为这不能很好地对枚举进行维护,正确应该是利用实例域,例如: 1 /** 2 * 枚举类型错误码 3 * Created by yulinfeng on 8/20/17. 4 */ 5 public enum ErrorCode { 6 FAILURE(0), 7 SUCCESS(1); 8 9 private final int code;…