Java1-刘明俊 1407084212

[1407084212lmj]

删除后三只羊

int len=sheepList.size();
int count=0;
Iterator<Sheep> itr=sheepList.iterator();
while(itr.hasNext()){
    if(count>len-4){
        itr.next();
        itr.remove();
    }
    else {itr.next();
    count++;
    }
}

往文件中加

package cn.edu.nuc.NewClass4;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class test {

public static void main(String[] args) {
        // TODO Auto-generated method stub
        File file = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest");
        File file1 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\1\\2");
        File file2 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\helloworld.txt");
        File file3 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\1\\2\\helloworld1.txt");
        File file4 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\1\\2\\helloworld2.txt");
        File file5 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\1\\2\\helloworld3.txt");
        File file6 = new File("E:\\Android\\Eclipse_workspace\\NewClass4\\iotest\\1\\2\\helloworld4.txt");
        try {
            file.mkdir();
            file1.mkdirs();
            file2.createNewFile();
            file3.createNewFile();
            file4.createNewFile();
            file5.createNewFile();
            file6.createNewFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String[] name=file.list();
        for(int i=0;i<name.length;i++){
            System.out.println(name[i]);
        }
        OutputStream IO = null;
        File[] Name=null;
        Name=file1.listFiles();
        System.out.println(Name.length);
        for(int i=0;i<Name.length;i++){
        try {
            IO=new FileOutputStream(Name[i], true);
            String s="中北大学安卓实验室";
            IO.write(s.getBytes());
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }try {
            IO.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        }
    }
}

Java中Runnable和Thread的区别

package cn.edu.nuc.NewClass5;
public class test {
public static void main(String[] args) {
        // TODO Auto-generated method stub
        ThreadExtend H1=new ThreadExtend("一号");
        ThreadExtend H2=new ThreadExtend("二号");
        ThreadExtend H3=new ThreadExtend("三号");
        H1.start();
        H2.start();
        H3.start();
        ThreadImpl h=new ThreadImpl("一号");
        new Thread(h).start();
        new Thread(h).start();
        new Thread(h).start();
    }
}
class   ThreadImpl implements Runnable{
    private int number =10;
    private String name;
    public ThreadImpl(String name) {
        this.name = name;
    }
    @Override
    public void run() {
        // TODO Auto-generated method stub
        System.out.println("我是实现Runnable");
        for(int i=0;i<10;i++){
            System.out.println("Runnable线程："+this.name+",i="+number--);
            if(number<1)
                break;
        }
    }
}
class   ThreadExtend extends Thread{
    private int number =10;
    public ThreadExtend(String name){
        super(name);
    }
    public ThreadExtend(){
        super();
    }
    public void run(){
        for(int i=0;i<10;i++){
            if(number<1)
                break;
            System.out.println("Thread线程:"+this.getName()+number--);
        }
    }
}