Core Java卷I

Preface 前言：

1.Its built-in security and safety features are reassuring both to programmers and to the users of Java programs.

2.JDK--->Java Development Kit(Java开发工具);API--->Application Programming Interface(应用编程接口)

3.Our goal is to enable you to fully understand the Java language and library,not to give you an illusion of understanding.

4.Chapter 4 introduces encapsulation ,the first of two fundamental building blocks of object orientation ,and the Java language mechanism to implement it,that is,classes and methods.(Java实现封装的方式：类和方法)

5.Classes and encapsulation are only one part of the OOP story ,and Chapter 5 introduces 
the other,namely,inheritance.(Java面向对象的三种方式：类、封装和继承)

6.Inheritance lets you take an existing class and modify it according to your needs.

7.Exceptions give you an efficient way of separating the normal processing code from the error handling.

8.A thread is a flow of control within a program.

Chapter 1 An Introduction to Java(第一章 Java语言介绍)

1.Java is a whole platform, with a huge library, containing lots of reusable code, and an execution 
environment that provides services such as security, portability across operating systems, and automatic garbage collection.

2.Java "White Paper" Buzzwords: Simple; Object Oriented; Netword-Savvy; Robust; Secure; Architecture Neutral; Portable; Interpreted; High Performance; Multithread; Dynamic.

3.Simply stated, object-oriented design is a technique for programming that focuses on the data (= objects) and on the interfaces to that object.

4.The major difference between Java and C++ lies in multiple inheritance, which Java has replaced with the simpler concept of interfaces, and in the Java metaclass model (which we discuss in Chapter 5).

5.The single biggest difference between Java and C/C++ is that Java has a pointer model that eliminates the possibility of overwriting memory and corrupting data.

6.The compiler generates an architecture-neutral object file format—the compiled code is executable on many processors, given the presence of the Java runtime system. The Java compiler does this by generating bytecode instructions which have nothing to do with a particular computer architecture. Rather, they are designed to be both easy to interpret on any machine and easily translated into native machine code on the fly.

7.However, virtual machines have the option of translating the most frequently executed bytecode 
sequences into machine code, a process called just-in-time compilation.

8.The virtual machine has other advantages. It increases security because the virtual machine can check the behavior of instruction sequences. Some programs even produce bytecodes on the fly, dynamically enhancing the capabilities of a running program.

9.