basic java knowledge example & exercises
main material from oracle (pure english)
reference material On java8 (Chinese Edition)
What Is an Object?
What Is a Class?
What Is Inheritance?
What Is an Interface?
What Is a Package?
Questions and Exercises: Object-Oriented Programming Concepts
Variables
Primitive Data Types
Arrays
Summary of Variables
Questions and Exercises: Variables
Operators
Assignment, Arithmetic, and Unary Operators
Equality, Relational, and Conditional Operators
Bitwise and Bit Shift Operators
Summary of Operators
Questions and Exercises: Operators
Expressions, Statements, and Blocks
Questions and Exercises: Expressions, Statements, and Blocks
Control Flow Statements
The if-then and if-then-else Statements
The switch Statement
The while and do-while Statements
The for Statement
Branching Statements
Summary of Control Flow Statements
Questions and Exercises: Control Flow Statements
Classes
Declaring Classes
Declaring Member Variables
Defining Methods
Providing Constructors for Your Classes
Passing Information to a Method or a Constructor
Objects
Creating Objects
Using Objects
More on Classes
Returning a Value from a Method
Using the this Keyword
Controlling Access to Members of a Class
Understanding Class Members
Initializing Fields
Summary of Creating and Using Classes and Objects
Questions and Exercises: Classes
Questions and Exercises: Objects
Nested Classes
Inner Class Example
Local Classes
Anonymous Classes
Lambda Expressions
Method References
When to Use Nested Classes, Local Classes, Anonymous Classes, and Lambda Expressions
Questions and Exercises: Nested Classes
Enum Types
Questions and Exercises: Enum Types
Annotations Basics
Declaring an Annotation Type
Predefined Annotation Types
Type Annotations and Pluggable Type Systems
Repeating Annotations
Questions and Exercises: Annotations
Interfaces
Defining an Interface
Implementing an Interface
Using an Interface as a Type
Evolving Interfaces
Default Methods
Summary of Interfaces
Questions and Exercises: Interfaces
Inheritance
Multiple Inheritance of State, Implementation, and Type
Overriding and Hiding Methods
Polymorphism
Hiding Fields
Using the Keyword super
Object as a Superclass
Writing Final Classes and Methods
Abstract Methods and Classes
Summary of Inheritance
Questions and Exercises: Inheritance
Numbers
The Numbers Classes
Formatting Numeric Print Output
Beyond Basic Arithmetic
Summary of Numbers
Questions and Exercises: Numbers
Characters
Strings
Converting Between Numbers and Strings
Manipulating Characters in a String
Comparing Strings and Portions of Strings
The StringBuilder Class
Summary of Characters and Strings
Autoboxing and Unboxing
Questions and Exercises: Characters and Strings
Why Use Generics?
Generic Types
Raw Types
Generic Methods
Bounded Type Parameters
Generic Methods and Bounded Type Parameters
Generics, Inheritance, and Subtypes
Type Inference
Wildcards
Upper Bounded Wildcards
Unbounded Wildcards
Lower Bounded Wildcards
Wildcards and Subtyping
Wildcard Capture and Helper Methods
Guidelines for Wildcard Use
Type Erasure
Erasure of Generic Types
Erasure of Generic Methods
Effects of Type Erasure and Bridge Methods
Non-Reifiable Types
Restrictions on Generics
Questions and Exercises: Generics
Creating and Using Packages
Creating a Package
Naming a Package
Using Package Members
Managing Source and Class Files
Summary of Creating and Using Packages
Questions and Exercises: Creating and Using Packages
What Is an Exception?
The Catch or Specify Requirement
Catching and Handling Exceptions
The try Block
The catch Blocks
The finally Block
The try-with-resources Statement
Putting It All Together
Specifying the Exceptions Thrown by a Method
How to Throw Exceptions
Chained Exceptions
Creating Exception Classes
Unchecked Exceptions — The Controversy
Advantages of Exceptions
Summary
Questions and Exercises
I/O Streams
Byte Streams
Character Streams
Buffered Streams
Scanning and Formatting
Scanning
Formatting
I/O from the Command Line
Data Streams
Object Streams
File I/O (Featuring NIO.2)
What Is a Path? (And Other File System Facts)
The Path Class
Path Operations
File Operations
Checking a File or Directory
Deleting a File or Directory
Copying a File or Directory
Moving a File or Directory
Managing Metadata (File and File Store Attributes)
Reading, Writing, and Creating Files
Random Access Files
Creating and Reading Directories
Links, Symbolic or Otherwise
Walking the File Tree
Finding Files
Watching a Directory for Changes
Other Useful Methods
Legacy File I/O Code
Summary
Questions and Exercises: Basic I/O
Processes and Threads
Thread Objects
Defining and Starting a Thread
Pausing Execution with Sleep
Interrupts
Joins
The SimpleThreads Example
Synchronization
Thread Interference
Memory Consistency Errors
Synchronized Methods
Intrinsic Locks and Synchronization
Atomic Access
Liveness
Deadlock
Starvation and Livelock
Guarded Blocks
Immutable Objects
A Synchronized Class Example
A Strategy for Defining Immutable Objects
High Level Concurrency Objects
Lock Objects
Executors
Executor Interfaces
Thread Pools
Fork/Join
Concurrent Collections
Atomic Variables
Concurrent Random Numbers
For Further Reading
Questions and Exercises: Concurrency
Configuration Utilities
Properties
Command-Line Arguments
Environment Variables
Other Configuration Utilities
System Utilities
Command-Line I/O Objects
System Properties
The Security Manager
Miscellaneous Methods in System
PATH and CLASSPATH
Questions and Exercises: The Platform Environment
Introduction
Test Harness
String Literals
Character Classes
Predefined Character Classes
Quantifiers
Capturing Groups
Boundary Matchers
Methods of the Pattern Class
Methods of the Matcher Class
Methods of the PatternSyntaxException Class
Unicode Support
Additional Resources
Questions and Exercises: Regular Expressions
Date: 2021/6/12
current: collection finished, JAR almost finished (example excluded), start essential class/ system configuration
Date:2021/6/5
current: collection.aggregate operations.reduction
Date:2021/5/29
current: collection.interface ~-map interface
Date:2021/5/28
curent: pause concurrency, begin collection. ~ - interface.the list interface
Date: 2021/5/18
current: begin concurrency, pause for a while to do quantization experiment
Date: 2021/5/18
current: finish Basic I/O (basicly ignoring some part of Files), next: Concurrency
Date: 2021/5/16
current: Basic I/O, ~ - I/O from the command line
Date: 2021/5/15
current: Finish Exception
Date: 2021/5/12
current: Finish Learning the [Java Language](#Learning-the-Java-Language), next: Essential Java Classes
Date: 2021/5/12
current: Finish Generics
Date: 2021/5/11
current: Finish Numbers and Strings, begin Generics. ~ - Generrics/Type inference
Date: 2021/5/10
current: Strings
Date: 2021/5/8
current: Numbers and Strings
Date: 2021/5/7
current: Interfaces and Inheritance
-
java基础语法
-
基本数据类型，引用
-
类型转换，强转（低-》高，instanceof 能对比就能强转）
-
运算符: ? :, instance of
-
javaDoc
-
面向对象
-
修饰符, private protected, default(package private), public
-
异常
-
-
常用类
- Object
- Math
- Random
- 自动装箱，拆箱
- File，官方新版用Files
- Date
- String, StringBuffer, StringBuilder
-
collection framework
- 基本集合框架
- 流处理与lambda表达式
-
IO流
- 字节流
- 字符流
-
多线程
-
网络编程
- socket类
-
注解
-
反射