08-01 接口 异常 文件IO流

抽象类

public abstract class Animal {    public abstract void voice();    public abstract void run();}public class Dog extends Animal{    public void voice(){        System.out.println("汪汪");    }    public void run(){        System.out.println("狗跑的很快");    }}public class Test {    public static void main(String[] args) {        Dog dog=new Dog();        dog.voice();        dog.run();    }}

接口（简单）

public interface Fly {    public void fly();}public interface Run {    public void run();}public class Plane implements Fly,Run{    @Override    public void fly() {        System.out.println("飞机用引擎飞");    }    @Override    public void run() {        System.out.println("飞机起飞前先助跑");    }}public class Bird implements Fly{    @Override    public void fly() {        System.out.println("鸟用翅膀飞");    }}public class Car implements Run{    @Override    public void run() {        System.out.println("汽车直接启动，不用助跑");      }}public class Test {    public static void main(String[] args) {        Plane plane=new Plane();        plane.fly();        plane.run();        Bird bird=new Bird();        bird.fly();        Car car=new Car();        car.run();    }}

接口（复杂）

public interface Ink {    public String getInkColor();}public class InkSuzhou implements Ink{    @Override    public String getInkColor() {        return "黑色";    }}public class InkOther implements Ink{    @Override    public String getInkColor() {        return "红色";    }}public class InkFactory {    public static Ink createink(){        InkSuzhou ink=new InkSuzhou();        return ink;    }}public interface Paper {    public String getPaperSize();}public class PaperBeijing implements Paper{    @Override    public String getPaperSize() {        // TODO Auto-generated method stub        return "A4";    }}public class PaperOther implements Paper{    @Override    public String getPaperSize() {        // TODO Auto-generated method stub        return "B5";    }}public class PaperFactory {    public static Paper createpaper(){        PaperBeijing paper=new PaperBeijing();        return paper;    }}public interface Print {    public void  print(Paper paper,Ink ink);}public class PrintHP implements Print{    @Override    public void print(Paper paper, Ink ink) {        System.out.println("在"+paper.getPaperSize()+"纸上打印"+ink.getInkColor()+"内容");    //在A4打印黑色内容    }}public class PrintOther implements Print{    @Override    public void print(Paper paper, Ink ink) {        System.out.println("使用"+paper.getPaperSize()+"纸打印"+ink.getInkColor()+"内容");   //使用A4打印黑色内容    }}public class PrintFactory {    public static Print createprint(){        PrintHP print=new PrintHP();        return print;    }}public class Test {    public static void main(String[] args) {        Paper paper=PaperFactory.createpaper();        Ink ink=InkFactory.createink();        Print print=PrintFactory.createprint();        print.print(paper, ink);    }}

自定义异常

public class Student {     private int score;     public int getScore() {        return score;    }    public void setScore(int score) throws Failscores {        if(score<60){            throw new Failscores();        }        this.score = score;    }}public class Failscores extends Exception{    public Failscores(){        super("不及格的异常");    }    @Override    public void printStackTrace() {        System.err.println("成绩不理想");        super.printStackTrace();    }}public class Test {    public static void main(String[] args) {        /*        //运行时异常        System.out.println(1/0);        */        /*        //空指针异常,一个引用变量,没有指向任何实际的对象        Student[] stu=new Student[10];        System.out.println(stu[0].getAge());        */         Student lisi=new Student();         System.out.println("程序开始运行");            try {                lisi.setScore(50);            } catch (Failscores e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        System.out.println("程序运行结束");    }}

文件异常

public class Test {    public static void main(String[] args) {    System.out.println("系统开始运行");        File file=new File("d://a.txt");        try {            FileInputStream file1=new FileInputStream(file);            file1.read();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }finally{            //必须运行，不管是否捕获异常            System.out.println("处理完毕");        }    }}

文件IO流、异常

import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class FileTest {    public static void main(String[] args) {        File file=new File("d://s.txt");        if(file.exists()){            try {                file.createNewFile();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }        //文件写入        String words="踏天九境，踏天九桥";        try {            byte[] array=words.getBytes();            FileOutputStream out=new FileOutputStream(file);            out.write(array);            out.flush();            out.close();            System.out.println("文件写入完成");        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        //文件输出        System.out.print("文件内容：");        byte[] array=new byte[1024];        try {            FileInputStream in=new FileInputStream(file);            int num=in.read(array);            while(num!=-1){                System.out.println(new String(array, 0, num));                num=in.read(array);            }            in.close();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();    }}

内部类

//写在类内部的类public class Student {    private String name;    private int age;    public void study(){        System.out.println(this.name+"正在学习");    }    public String getName() {        System.out.println("姓名:"+name);        return name;    }    public void setName(String name) {        this.name = name;    }    public int getAge() {        System.out.println("年龄:"+age);        return age;    }    public void setAge(int age) {        this.age = age;    }    public class Pen{        String name;        String color;        public void write(){            System.out.println(Student.this.name+"写点东西");        }        public String getName() {            System.out.println("类型:"+name);            return name;        }        public void setName(String name) {            this.name = name;        }        public String getColor() {            System.out.println("颜色:"+color);            return color;        }        public void setColor(String color) {            this.color = color;        }       }}public class Test {    public static void main(String[] args) {        Student lisi=new Student();        lisi.setName("李斯");        lisi.setAge(18);        System.out.println(lisi.getName());        System.out.println(lisi.getAge());          lisi.study();        Pen pen=lisi.new Pen();        pen.setName("钢笔");        pen.setColor("蓝色");        System.out.println(pen.getName());              System.out.println(pen.getColor());             pen.write();    }}

局部类

//写在方法中的类public class Student {    private String name;    public void study(){         class Book{            String bookName="三国演义";            public void read(){                System.out.println(bookName);            }           }        Book book=new Book();        System.out.print(Student.this.name+"正在学习");        book.read();    }}public class Test {    public static void main(String[] args) {        Student lisi=new Student();        lisi.setName("李斯");        lisi.study();    }}

匿名内部类

//匿名内部类，当只使用一次时Paper paper=new Paper(){    @Override    public String getPaperSize() {        return "A4";    }};

正则表达式

//手机号 13 15 18Pattern p=Pattern.compile("^1(3|5|8)\\d{9}$");Matcher m=p.matcher("13445698735");boolean b=m.matches();System.out.println(b);//身份证号 18位，最后一位可能是x或XPattern p=Pattern.compile("^\\d{17}(x|X|\\d)$");Matcher m=p.matcher("13068219990205541x");boolean b=m.matches();System.out.println(b);//邮箱 [e-mail]|.cn|.netPattern p=Pattern.compile("^\\p{Alnum}{1,}\\@\\p{Alnum}+\\.(com|cn|net)$");Matcher m=p.matcher("[e-mail]");boolean b=m.matches();System.out.println(b);

Data 、Calendar（常用的工具类）

Date date=new Date();System.out.println(date.toString());System.out.println(date.getTime());Calendar rightNow=Calendar.getInstance();System.out.println(rightNow.get(Calendar.YEAR));System.out.println(rightNow.get((Calendar.MONTH))+1);System.out.println(rightNow.get(Calendar.DAY_OF_MONTH));rightNow.set(Calendar.DAY_OF_YEAR, rightNow.get(Calendar.DAY_OF_YEAR)+5);System.out.println(rightNow.get(Calendar.DAY_OF_MONTH));SimpleDateFormat format=new SimpleDateFormat("yyyy年MM月dd日   HH:mm:ss");System.out.println(format.format(date));SimpleDateFormat format1=new SimpleDateFormat("yyyy年MM月dd日   HH:mm:ss");String time="2015年08月01日   16:00:26";try {    Date date1=format1.parse(time);    System.out.println(date1.getTime());} catch (ParseException e) {    e.printStackTrace();}