core java volume 2

comparable2publicint Comparato (Employee Other)3 {4 return Double. Compare (salary, other.salary); 5 }}Note the type conversion of the Object parameterWhy not provide a Comparableto method directly in the employee class? The main reason is that Java is a strongly typed (strongly typed) language. When the method is called, the compiler checks to see if the method exists.1 PackageCc.openhome;2 Importja

Basic data typesJava is the language of a strong data classThere are 8 basic data types, including:Integer 4 types Int (4 bytes) short (2 bytes) long (8 bytes) byte (1 bytes)The range and machine-independent lengths of integers in Java are certain, and do not cause integer overflow across platformsFloat type two double floatThe length of the double is twice times the length of the float, the double value bu

throws interrupterexception{ Sleep (delay);}10.synchronized keywords Public synchronized Voi Method () { method body}Equivalent to Public void method () { this. Intrinsiclock.lock (); Try { method body }finally{ this. Intrinsiclock.unlock ( ); }}11. Use Object Lock public class bank{ public void transfer (int from, int to, int mount) { synchronized -=amount; Accounts[to] +=amount; } System.out.println (...); private double [] Account; p

box containing a message and an OK button, which will be in the center of its parent component.API javax.swing. Timer 1.2Timer (int interval, ActionListener Listener)Constructs a timer that advertises listener once every interval millisecond.void Start ()Start the timer. Once the boot is successful, the timer invokes the listener's actionperformed.API void Stop ()Stop the timer, and once the stop is successful, the timer will not be actionperformed to call the listener.Java. Awt. Toolkit 1.0Sta

Over the last one months. Just swallowed the book over. The book is long enough to say 706 pages. I have never been a person who likes to record, have been reading what books have been read to throw aside, may sometimes have so a little want to record down the impulse, but the calculation time is too tight, a lot of youshiwuzhong, after all, research and research program is only a hobby of their own, but did not expect to sign a programmer's work. Alas, this God is too much fun, let a study of e

Tag: Util indicates date () Date class specifies date standard int ringIn the Java core Technology volume, the first date class appears in a very high frequency, so we have a small integration of the date classThe date class has twoThe date class represents a specific time classThis constructor assigns a Date object and initializes it to represent the specified n

FileOutputStream can provide input and output streams attached to a disk file. The parameter is a file name or full pathname.Use System.getproperty ("User.dir") to get the current pathSystem. out. println (System.getproperty ("user.dir")); -D:\WorkSpace\Eclipse\IOTestThe full path we need to get the operating system operator, such as under Windows:System. out. println (File.separator); -/ You can also use the double backslash notation: c:\\windows\\123.txtA basic read-file program:ImportJav

schematic, the inside of the compiler is certainly not outer An implicit reference to an external class is set in the constructor. The compiler modifies all constructors for the inner class, adding a parameter that references the external class. Even if you do not define a constructor for an inner class, the compiler generates a default constructor for the inner class. such as:Publictimeprinter (talkingclock clock) {outer = clock;}When an inner class object is created in the Start method, th

List 13.1 Linklist/linkedlisttest.javaLinklist of Java ContainersPackage Linklist;import Java.util.linkedlist;import Java.util.list;import Java.util.listiterator;public class Linklisttest{public static void Main (String args[]) {list Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced. Java Core Technology

for another thread to notify the scheduler of a condition, it enters its own wait state. This occurs when you call the Object.wait method or the Thread.Join method, or you wait for lock or condition in the Java.util.concurrent library. Timed Waiting (timed Wait) There are several methods that have a timeout parameter. Calling them causes the thread to enter a timed wait (time waiting) state. This status will be maintained until the timeout expires or the appropriate notification i

1. Static constants:Static variables are used relatively little, but static constants are used more, for example, a static constant is defined in the Math class:public static Final PI = 3.141592653;In the program, this constant can be obtained in the form of Math.PI.If the keyword static is omitted, Pi becomes an instance field of the math class and needs to be accessed through an object of the math class, and each math object has its own copy of Pi."Java