Java Basic Three

1, multithreaded Programming:

The difference between a thread and a process: the process requires a separate memory space, the process shuts down so the thread shuts down, and the thread can share memory and resources, and the thread shutdown process does not shut down.

The thread class and the Runnable class, the creation of threads: 1, inherits the thread class instantiation of a thread, then overrides the thread's Run method, then calls the Start method to start the thread; 2, implements a runnable interface, Create a runnable class and instantiate and pass the instance into the constructor of the thread class, and then call the Start method of the thread class instance;

Thread Priority (SetPriority): The higher the number, the higher the power, the default number is 5;

The difference between setsleep () and Tostop () is that the former is suspended and the latter is directly stopped;

Thread synchronization: synchronization block, keyword synchronized (lock object), sometimes deadlock;

2,java Collection Framework:

The collection framework is divided into collection interfaces and iterator interfaces (ergodic): The 1,collection interface is divided into set sets (objects are not sequential and cannot be duplicated) and list sets (objects are ordered and can be duplicated);

Map interface consists of key-value pairs, key objects are not repeatable, key values can be repeated;

The iterator () method of the iterator walker accesses either an element or a foreach method;

ArrayList: Generic: Canonical data type to avoid type conversion errors;

ArrayList and LinkedList: The former is of high efficiency, the latter is efficient in inserting and deleting;

3, Reflection:

Class loading mechanism: Load, link, initialize;

Use reflection to view class information: Common Method Class.forName ("Fully qualified class name");

Garbage collection mechanism, Finalize () method;

4,java Graphical Interface Programming:

The graphical interface includes AWT (heavyweight components) and swing (lightweight components), containers and components, and containers as well as components;

Heavyweight containers in swing include forms, dialog boxes, windows, and small programs.

The layout of the container, common flow layout, border layout, grid layout and box layout;

Java Basic Three