Java Native Interface(JNI) allows Java applications to call native methods, which are special methods written in native programming languages such as C or C++. Historical usages of native methods Access to platform-specific facilities such as registr…

Static utility methods are particularly good candidates for generification. The type parameter list, which declares the type parameter, goes between the method's modifiers and its return type. // Generic method public static <E> Set<E> union(S…

Principle readObject method is effectively another public constructor, and it demands all of the same care as any other constructor. Just as a constructor must check its arguments for validity (Item 38) and make defensive copies of parameters where a…

Lazy initialization - It decreases the cost of initializing a class or creating an instance, at the expense of increasing the cost of accessing the lazily initialized field. Depending on what fraction of lazily initialized fields eventually require i…

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 8 General Programming Item 45: Minimize the scope of local variables local variables应该在他们要被用的地方声明,而不应该,比如,全部声明在方法开头.而且在声明的时候,记得要初始化.有个例外,比如你的IQueryable<T> localv需要在接下来的if else中分别初始化成不同的值,那么你可以在if之前先声明(我自己瞎举的例子). 如果某个local variable只是这个循环需要的,那…

<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…

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;…