/*---------------------数组模拟链表--数三退一------------- *这里面为我所有学习JAVA时的例程，希望能给大家一点帮助. * public class HelloWorld {public static void main(String args[]) {int length = 234;int[] a = new int[length];for(int i=0;i<length - 1;i++) {a[i] = i + 1;}int count = 0 , index = 0 , oldIndex = 0;while(length >1) {count++;if(count == 3) {int i = index;a[oldIndex] = a[index];index = a[index];a[i] = -1;count = 0;length --;continue;}oldIndex = index;index = a[index];}for(int i=0;i<a.length;i++) {if(a[i] != -1) System.out.println(i);}} }----------------------消费者和生产者------------------ import java.util.*; public class HelloWorld {public static void main(String[] args) {ManTouStack mts = new ManTouStack();Consumer c = new Consumer(mts);Producer p = new Producer(mts);new Thread(c).start();new Thread(p).start();} }class Consumer implements Runnable{ManTouStack mts = null;public void run() {try{for(int i=0;i<=30;i++) {ManTou mt = new ManTou(i);mts.pushManTou(mt);System.out.println("做了一个馒头" + mt);Thread.sleep((int)(Math.random() * 500));}} catch(InterruptedException ae) {ae.printStackTrace();}}public Consumer(ManTouStack mts) {this.mts = mts;}}class Producer implements Runnable {ManTouStack mts = null;public void run() {try{for(int i=0;i<30;i++) {ManTou mt = mts.popManTou();System.out.println("吃了一个馒头" + mt);Thread.sleep((int)(Math.random() * 500));}} catch(InterruptedException ae) {ae.printStackTrace();}}public Producer(ManTouStack mts) {this.mts = mts;}} class ManTou {int id;public ManTou(int id) {this.id = id;}public String toString() {return "" + this.id;}}class ManTouStack {static int index = 0;ManTou[] mts = new ManTou[6];public synchronized void pushManTou(ManTou mt) {if(index == mts.length) {try{this.wait();} catch(InterruptedException ae) {ae.printStackTrace();}}this.notifyAll();mts[index] = mt;index ++;}public synchronized ManTou popManTou() {if(index == 0) {try{this.wait();} catch(InterruptedException ae) {ae.printStackTrace();}}this.notifyAll();index --;return mts[index];}} ----------------------第十八个程序(多线程的练习)--------------- public class HelloWorld {public static void main(String args[]) {// TestThread1 tt = new TestThread1();// tt.setPriority(6);//设置线程优先级,等级为1-10,系统共有三个常量优先级MAX_PRIORITY=10;MIN_PRIORITY=1;NORM__PRIORITY=5; // tt.start();// try{// tt.join();//合并某一线程到正在执行线程中,正在执行线程需等合并线程执行返回方能继续执行// } catch(InterruptedException ae) {// ae.printStackTrace();// }// currentThread()拿到当前线程对象// isAlive()判断线程是否存活//Thread t = new Thread(tt);//t.start();// for(int i=0;i<=100;i++) {// if(i % 5 == 0) {// Thread.yield();//该方法为该线程暂时停止运行// }// System.out.println("Main-" + i);// }// System.out.println(tt.getPriority());//取进程优先级DeathLock dl = new DeathLock();dl.main();}} class TestThread1 extends Thread implements Runnable {//实现线程有两种方式，实现Runable接口或从Thread继承public void run() {//该方法为Thread执行主方法for(int i=0;i<=100;i++) {System.out.println("-------Thread-" + i);}} } class DeathLock implements Runnable {int flag = 0;static DeathLock o1 = new DeathLock() , o2 = new DeathLock();public static void main() {DeathLock dl = new DeathLock();DeathLock dl2 = new DeathLock();Thread t1 = new Thread(dl);Thread t2 = new Thread(dl2);t1.start();dl2.flag = 1;t2.start();}public void run() {try {if(flag == 0) {synchronized(o1) {System.out.println("o1已经锁定");Thread.sleep(3000);synchronized(o2) {System.out.println("0");}}}if(flag == 1) {synchronized(o2) {System.out.println("o2已经锁定");Thread.sleep(3000);synchronized(o1) {System.out.println("1");}}}} catch(InterruptedException ae) {ae.printStackTrace();}} } -------------------------第十七个程序(IO类的演示)---------------------- import java.io.*; public class HelloWorld {public static void main(String args[]) {FileByte fb = new FileByte();TestInput ti = new TestInput();TestObject to = new TestObject();to.name = "诸葛亮";to.level = 21; to.death = true;// to.outTestO();// to.inTestO();//fb.testFileByte();//FileChar.testFileChar();//BufferedIo.testBuffered();//ti.testInput();//TestPrint.testPrint();TestPrint.testPrintFile(args[0]);} } class FileByte {public void testFileByte() {try {FileInputStream in = new FileInputStream("D:/javac/heLLoWorld.java");FileOutputStream ou = new FileOutputStream("d:/Test/test.txt");int count1,count2 = 0;while((count1 = in.read()) != -1) {ou.write(count1);count2++;System.out.print((char)count1);}System.out.println("共复制" + count2 + "个字节到测试文件....");in.close();ou.close();} catch(FileNotFoundException ae) {System.out.println("未找到文件...");} catch(IOException ae) {System.out.println("文件读写错误...");System.exit(-1);}} } class FileChar {public static void testFileChar() {try {FileReader in = new FileReader("D:/javac/HELLOWORLD.java");FileWriter ou = new FileWriter("d:/test/test.dat");int count1,count2 = 0;while((count1=in.read())!= -1) {ou.write(count1);count2++;System.out.print((char)count1);} System.out.println("共复制" + count2 + "个字节到测试文件....");ou.close();in.close();} catch(FileNotFoundException ae) {System.out.println("文件未找到....");System.exit(-1);} catch (IOException ae) {System.out.println("文件读写错误...");System.exit(-1);}} } class BufferedIo {public static void testBuffered() {int count;try {BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("d:/test/OutputStream.txt"));BufferedInputStream bis = new BufferedInputStream(new FileInputStream("d:/javac/HelloWorld.java"));BufferedReader br = new BufferedReader(new FileReader("d:/javac/HelloWorld.java"));BufferedWriter bw = new BufferedWriter(new FileWriter("d:/test/BufferedReader.miz"));OutputStreamWriter osw = new OutputStreamWriter(bos);//输出字节流转字符流InputStreamReader isr = new InputStreamReader(bis);//输入字节流转字符流// while((count=br.read()) != -1) {//打印带缓冲区的字符// System.out.print((char)(count));// }// while((count = isr.read()) != -1) {//转换输入输出流大小// System.out.print((char)(count));// }System.out.println(isr.getEncoding());bos.close();bis.close();br.close();bw.close();osw.close();isr.close();} catch(FileNotFoundException ae) {System.out.println("文件未找到....");System.exit(-1);} catch(IOException ae) {System.out.println("文件读写错误...");System.exit(-1);}} } class TestInput {public void testInput() {try {BufferedInputStream bos = new BufferedInputStream(System.in);InputStreamReader isr = new InputStreamReader(bos);BufferedReader is = new BufferedReader(isr);String c = is.readLine();while(c != null) {if(c.toUpperCase().equals( "EXIT")) {break;} else {System.out.println(c);}c = is.readLine();}is.close();isr.close();bos.close();System.exit(-1);} catch(IOException ae) {System.out.println("文件读写错误...");System.exit(-1);}} } class TestObject implements Serializable {//想实现类的序列化(输出)必须实现该标志接口,否则报错String name;//Externalizable接口是控制序列化过程的接口,继承至Serializableboolean death;int level;transient float bar =(float) (2.132);//透明的,即是在实现序列化是不保存该值public void outTestO() {try {FileOutputStream fod = new FileOutputStream("D:/test/testObj.dat");ObjectOutputStream oos = new ObjectOutputStream(fod);oos.writeObject(this);oos.flush();oos.close();fod.close();} catch(FileNotFoundException ae) {System.out.println("文件未找到....");} catch(IOException ae) {System.out.println("文件写出错误....");}}public void inTestO() {try {FileInputStream fis = new FileInputStream("D:/test/testObj.dat");ObjectInputStream ois = new ObjectInputStream(fis);TestObject a = (TestObject)(ois.readObject());System.out.println("人物名字为：" + a.name + " 人物等级为：" + a.level + " 游戏进度为：" + a.bar + " 角色是否死亡：" + a.death);fis.close();ois.close();} catch(FileNotFoundException ae) {System.out.println("文件未找到....");} catch (ClassNotFoundException ae) {System.out.println("角色读取失败...");} catch(IOException ae) {System.out.println("数据读入错误...");}} }class TestPrint {public static void testPrint() {try {String s = null;FileOutputStream fos = new FileOutputStream("D:/test/testprint.txt");PrintStream ps = new PrintStream(fos);System.setOut(ps);System.out.print("这是测试信息");ps.flush();ps.close();fos.close(); } catch(IOException ae) {ae.printStackTrace(); }}public static void testPrintFile(String f) {if(f != null) {testP(f,System.out);}}public static void testP(String s,PrintStream a) {try {FileReader fr = new FileReader(s);BufferedReader br = new BufferedReader(fr);String s1 = "";while(s1 != null ) {s1 = br.readLine();a.println(s1);}fr.close();} catch(FileNotFoundException ae) {ae.printStackTrace();} catch(IOException ae) {ae.printStackTrace();}}} -----------------------第十六个程序(容器的用法、应用)---------------- import java.util.*; public class HelloWorld {private static final Integer in = new Integer(1);public static void main(String args[]) {testWords(args);}public static void testWords(String[] s) {Map m = new TreeMap();for(int i=0;i<s.length;i++) {Integer b =(Integer)m.get(s[i]);m.put(s[i],b == null ? new Integer(1) : new Integer(b.intValue() + 1));}System.out.println(m.size() + " Words in the args");System.out.println(m);} } -----------------------第十五个程序(容器的自动解包、打包Auto-boxing/unboxing)------------------ import java.util.*; public class HelloWorld {public static void main(String args[]) {Map m1 = new TreeMap();Map m2 = new HashMap();m1.put("one",new Integer(1));m1.put("two",new Integer(2));m1.put("three",new Integer(3));m2.put("a",new Integer(1));m2.put("b",new Integer(2));// m1.put("one",1);// m1.put("two",2);// m1.put("three",3);// m2.put("a",1);// m2.put("b", 2);System.out.println(m1.size());System.out.println(m1.containsKey("two"));System.out.println(m2.containsValue(new Integer("2")));Map m3 = new HashMap(m1);m3.putAll(m2);System.out.println(m3);} } -----------------------第十四个程序(容器的演示)-------------------import java.util.*; public class HelloWorld {public static void main(String []args) {Collection h = new HashSet();HashMap M = new HashMap();Set s = new HashSet();List c = new ArrayList();List li = new ArrayList();List link = new LinkedList();c.add(new String("aaa"));c.add(new Long(123));c.add(new Name("f1","n1"));c.add(new Integer(234));System.out.println("ArrayList取出内容：" + (Name)c.get(2));System.out.println(" 遍历容器：" );for(Object o : c) {//遍历数组容器System.out.print(" " + o);}link.add("a");link.add("b");link.add("c");link.add("d");System.out.println("LinkedList取出内容：" + (String)link.get(0));h.add(new Name("f2","n2"));h.add(new Name("f1","n1"));h.add(new Name("f3","n3"));Iterator i = h.iterator();//System.out.println(i.hasNext());while(i.hasNext()) {//移除内容Name l = (Name)i.next();if(l.equals(new Name("f2","n2"))){i.remove();}}System.out.println(h);System.out.println(h.size());int[] arr = {1 , 2 ,3 ,4 ,5};//增强的for循环 jdk1.5以后才提供for(int z : arr) {//遍历数组System.out.print(z);}} } class Name {private String firstName , lastName;public Name(String f , String l) {this.firstName = f;this.lastName = l;}public String getfirstName(){return firstName;}public String getlastName() {return lastName;}public String toString() {return firstName + " " + lastName;}public boolean equals(Object obj) {if(obj instanceof Name) {Name n = (Name)(obj);return (n.firstName.equals(firstName)) && (n.lastName == this.lastName);}return super.equals(obj);}public int hashCode() {return firstName.hashCode();} } -----------------------第十三个程序(树状列文件目录演示、枚举类型演示)-------------- import java.io.*;//引用 enum Mycolor {red , blue , green , bliack}//定义一个枚举类型 public class HelloWorld {public static void main(String[] args) {Mycolor u = Mycolor.red;//使用枚举类型//Mycolor d = Mycolor.asdf;//不存在此枚举,报错File f = new File("d:/javac/mydir1");file_list(f,0);}public static void file_list(File f , int l) {File c[] = f.listFiles();String s = "";for(int i=0;i<l;i++) {s = s + " ";}for(int i=0;i<c.length;i++) {if(c[i].isDirectory() == true) {l++;System.out.println(s + c[i].getName());file_list(c[i] , l);} else {System.out.println(s + c[i].getName());}}} } --------------------第十二个程序(String File常用方法练习)------------------- import java.io.*; public class HelloWorld {public static void main(String[] args) {file_Demo();}public static void string_Demo() {String a = "Hello Java",b = "Sun , MiscSoft , Unixc" ;int c = 123456789;// String d[] = a.split(",");//以","分割字符串// String e = String.valueOf(c);//通过String.valueOf()将其转换为字符串,可转换所有类型(包括基本类型和引用类型)// b.charAt(5);//返回指定位置的字符// b.length();//返回字符串字符长度// b.indexOf("M");//返回指定字符串出现的第一个位置// b.indexOf(3,"M");//返回指定字符串从指定位置开始出现第一次的位置// b.equalsIgnoreCase(a);//比较两个字符串是否相同,忽略大小写// b.replace("m","b");//将替换所有目标字符// b.startsWith("assd");//判断是否以指定字符串开头// b.endsWith("sdfsd");//判断是否以指定字符串结尾// b.toUpperCase();//全转换为大写// b.toLowerCase();//// b.substring(5);//返回指定位置后的字符串// b.substring(3,5);//返回从指定位置开始到指定位置结尾的字符串// b.trim();//去掉字符串首尾空格}public static void file_Demo() {// canRead()// canWrite()// exists()// isDirectory()// ifFile()// isHidden()// lastModified()// length()// getName()// getPath()// creatNewFile()// delete()// mkdir()// mkdirs()// getPatentFile()String separartor = File.separator;String filename = "myfile.txt";String directory = "mydir1" + separartor + "mydir2";//String directory = mydir1/mydir2;File f = new File(directory,filename);if(f.exists() == true) {System.out.println("文件名：" + f.getAbsolutePath() + "\t文件大小：" + f.length() );} else {f.getParentFile().mkdirs();try{f.createNewFile();} catch (IOException e) {e.printStackTrace();}}} } -----------------------第十一个程序(二维数组)------------------------------ public class HelloWorld {public static void main(String args[]) {String a = "1 , 2 ; 3 , 4 , 5 ; 6 , 7 ,8 ,9";StringBuffer b = new StringBuffer("这是一个测试");String[] c = a.split(";");String[][] d = new String[c.length][];for(int i=0;i<c.length;i++) {d[i] = c[i].split(",");}System.out.println(d[1][2].trim());} } ----------————————---第十个程序(数组拷贝)------------------------- public class HelloWorld {public static void main(String []args) {int []a = new int[5];a[0] = 12 ; a[1] = 1 ; a[2] = 29 ; a[3] = 42 ; a[4] = 122 ; int[] b = new int[6];System.arraycopy(a,0,b,2,3); 参数：被拷贝数组 起始拷贝位置 拷贝至数组 起始拷贝位置 拷贝长度 System.out.println(b[1]);} } ---------------------第九个程序(查找方法练习 折半法)---------------------- public class HelloWorld {public static void main(String args[]) {int test[] = {1,4,6,8, 12,15,17,19,22,27,35,48,50,51,53,55,59,62};System.out.print(middleSearch(test,19));}public static int middleSearch(int[] a ,int m) {if(a.length == 0) return -1;int start = 0 , end = 0 , middle = 0;end = a.length - 1;middle =(int)((start + end)/2);while(start <= end) {if(a[middle] == m) return middle;if(a[middle] > m) {end = middle - 1;}if(a[middle] < m) {start = middle + 1;}middle =(int)((start + end)/2);}return -1;}} ----------------------第八个程序(数组的练习)------------------------ public class HelloWorld {public static void main(String[] args) {double[] a = {1.0,2.2,2.4,3.1};//数组静态申明sortarray(args);num3quit.num3quit();System.out.print(binarySearch(a,3));}public static void printarray(double[] b) {for (int i=0;i<b.length;i++) {//打印数组元素System.out.println(b[i]);}}public static void sortarray(String[] c) {double d[] = new double[c.length];//数组动态申明for(int i=0;i<c.length;i++) {//数组类型转换d[i] = Double.parseDouble(c[i]);}for(int i=0;i<d.length;i++) {//排序方法一 选择排序 for(int j=i;j<d.length;j++) { double temp = 0; if(d[i] > d[j]) { temp = d[j]; d[j] = d[i]; d[i] = temp;}}}double temp;//方法二 选择排序效率优化int k;for(int i=0;i<d.length;i++) {k = i;for(int j=k;j<d.length;j++) {if(d[k] > d[j]) {k = j;}}if(k != i) {temp = d[i];d[i] = d[k];d[k] = temp;}}printarray(d);double temp;//冒泡排序法for(int i=d.length-1;i>=0;i--) {for(int j=0;j<i;j++) {if(d[j] > d[j+1]) {temp = d[j+1];d[j+1] = d[j];d[j] = temp;}}}printarray(d);}}class num3quit {//数组 数三退一算法,五百人,求最后留下人的编号public static void num3quit() {boolean[] pe = new boolean[500];//定义五百人数组并初始化,用真假表示其是否还在数组中for(int i=0;i<pe.length;i++) {pe[i] = true;}int index = 0 , temp = 0 , num = pe.length;while (num > 1) {//判断循环直到只有最后一个剩余为止if(index == pe.length) {index = 0;}if(pe[index] == true) {temp ++;if(temp == 3) {pe[index] = false;temp = 0;num --;}}index++;}for(int i=0;i<pe.length;i++) {//寻找出最后一个存在的人,并找出他的位置if(pe[i] == true) {System.out.println(i+1);}}}public static void num3quit_() {//双向链表 数三退一算法,五百人,求最后留下人的编号}} ------------------------第七个程序(异常的捕捉及处理)--------------public class HelloWorld {//异常捕捉以及异常处理演示public static void main(String args[]) {int arr[] = {1 , 2 , 3};try {System.out.println(arr[1]);//可出现数组异常错误,若出现错误后面语句不会执行System.out.println(3/9);//可出现除零异常,若出现错误后面语句不会执行System.out.println(division(1,0));} catch (ArithmeticException a){System.out.println(a.getMessage());System.out.println("出现除零错误...");} catch (ArrayIndexOutOfBoundsException b) {System.out.println("出现数组超界...");b.printStackTrace();//printStackTrace() 打印出堆栈信息b.getMessage();//getMessage()取出错误信息} finally {//此关键字无论如何都被执行}}public static double division(double div , double bediv) {if(bediv == 0) {throw new ArithmeticException("被除数为零");//申明抛出异常类型}return div/bediv;}public static void test() throws ArithmeticException {//申明抛出异常,下面就可以直接调用不用异常处理了,但是调用这个方法的对象需要进行异常处理division(3,1);}}----------------------第六个程序(抽象类以及多态)-------------------public class HelloWorld {public static void main(String args[]) {Student s = new Student("张瑞");Testinterface t = new Student("王天");//申明一个Testinterface的引用变量t来指向Student对象.s.getName();t.sing();//t.getname();//由于t是Testinterface引用变量,故没有getname方法}}interface Testinterface {//接口可以继承其他接口,并添加新的属性和方法public static final int i = 5;//接口默认申明属性为 public static final 也只能是public static finalpublic void sing();//接口方法默认属性为public 也只能为public public void sleep();}interface testinterface {public void study();public void sleep();}class Student implements Testinterface {//申明引用Testinterface接口private String name;Student(String name) {this.name = name;}public void study() {System.out.println("学生学习...");}public void sing() {System.out.println("学生唱歌...");}public void sleep() {System.out.println("学生睡觉...");}public void getName() {System.out.println("学生姓名：" + name);}}--------------------第五个程序(final关键字)---------------final class testfinal {//此类不能被继承public final int i = 8 ;//此处i不能被修改public void t(final int j) {}//此处参数j一旦传值则不允许再修改public final void m() {}//此方法不能被重写}--------------------第四个程序(练习对象转型)------------public class HelloWorld {public static void main(String []args) {CastingDog d1 = new CastingDog(1,2,8);CastingDog d2 = new CastingDog(1,2,3);System.out.print(d1.compare(d2));}}class CastingDog {public int length , wide , high;public boolean compare(CastingDog a) {if(a instanceof CastingDog) {CastingDog v = (CastingDog)a;if(length == v.length & wide == v.wide & high == v.high) {return true;}else return false;}else{return false;}}CastingDog(int l , int w , int h) {length = l;wide = w;high = h;}}-------------------第三个程序(练习动态绑定和抽象类,共四个类)----------------------------public class HelloWorld {public static void main(String []args) {Cat c = new Cat("bigcat" , "green");Dog d = new Dog("cooldog" , "blue");Lady l1 = new Lady("老公" , d);Lady l2 = new Lady("老婆" , c);l1.mypetenjoy();l2.mypetenjoy();}}abstract class Animal {//由于类中有抽象方法,所以类必需申明为抽象类private String name;Animal() {}Animal(String name) {this.name = name;}//此程序段可用抽象方法实现//public void enjoy() {// System.out.println("叫声...");//} public abstract void enjoy();//抽象方法,不需要实现,抽象方法必须被重写,抽象类必须被继承}class Cat extends Animal {private String eyescolor;public void enjoy() {System.out.println("猫叫声....");}Cat(String name , String es) {super(name);this.eyescolor = es;}}class Dog extends Animal {private String furcolor;public void enjoy() {System.out.println("狗叫声....");}Dog(String name , String fc) {super(name);this.furcolor = fc;} }class Lady {private String name;private Animal pet;Lady(String name , Animal pet) {this.name = name;this.pet = pet;}public void mypetenjoy() {pet.enjoy();}} ------------第二个程序(练习类的继承和构造方法的重载,共三个类)----------------------------------class Teacher extends Person {private String profession;Teacher(String p) {super ("zr");profession = p;}public String info() {return super.info() + " profession: " + profession;}}class Person {private String name;private String location;Person(String n) {name = n;location = "beijing";}Person(String n , String l) {name = n;location = l;}public String info() {return "name:" + name + " location: " + location;}}class Student extends Person {private String school;Student(String n , String s) {this(n , s , "beijing");}Student(String name , String l, String school) {super(name,l);this.school = school;}public String info() {return super.info() + " school: " + school;}}-------------第一个程序(练习构造方法重载 , 共一个类)-----------------class OnePoint {double x,y,z;public void setx(double _x){x = _x;}public void sety(double _y) {y = _y;}public void setz(double _z) {z = _z;}public void juli(OnePoint e) {System.out.print("\n\"p\"点= "+this.x+" "+this.y+" "+this.z);System.out.print("\n\"p\"点= "+e.x+" "+e.y+" "+e.z);System.out.print("\n距离= "+ ((x-e.x)*(x-e.x) + (y-e.y)*(y-e.y) + (z-e.z)*(z-e.z)));}public OnePoint(){}public OnePoint(double _x ,double _y , double _z) {z = _z;x = _x;y = _y;}}*************************************************************************/
