java1-郭政伟-1407064223

[zhweiGuo]

1.批量创建文件
package cn.edu.nuc;

import java.io.File;
import java.io.FileNotFoun-dException;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileTest1{
public static void main(String[] args){
File directory = new File("D:"+File.separator+"direc");
OutputStream output = null;

    if (!directory.exists())    //若不存在“direc”这个文件夹，则创建
        directory.mkdir();
    try{    //创建10个txt文件
        for (int i = 0; i < 10; i++){
            File file = new File("D:"+File.separator+"direc"+File.separator+"hello"+ i +".txt");
            if (!file.exists())
                file.createNewFile();
        }
    }catch(IOException e){
            e.printStackTrace();
        }

    String[] fileNames = directory.list();  //把directory中的文件名字保存在数组中
    for (int i = 0; i < 10; i ++){  //向文件中写入
        File hellos = new File("D:"+File.separator+"direc"+File.separator+"hello"+ i +".txt");
        try{
            FileOutputStream out = new FileOutputStream(hellos);
            String str = new String("hello world "+ i);
            byte[] bstr = str.getBytes();
            out.write(bstr);
        }catch(FileNotFoundException e){
            e.printStackTrace();
        }catch(Exception e){
            e.printStackTrace();
        }

    }


}

}

2.删除羊
package cn.edu.nuc;

import java.util.ArrayList;
import java.util.Iterator;

public class TestCollection {
public static void main(String[] args){
ArrayList sheepList = new ArrayList();
sheepList.add(new sheep("喜羊羊"));
sheepList.add(new sheep("美羊羊"));
sheepList.add(new sheep("懒羊羊"));
sheepList.add(new sheep("沸羊羊"));
sheepList.add(new sheep("慢羊羊"));
sheepList.add(new sheep("暖羊羊"));

    for (sheep s : sheepList)
        System.out.println(s.name);

    int n = 3;  //删除羊的只数
    int length = sheepList.size();
    //从后面删除n只羊
    for (int i = length -1; i >= length - n; i--) {
        sheepList.remove(i);
    }
    //从前面删除n只羊
    for (int i = 0; i < n; i++)
        sheepList.remove(i);

    Iterator it = sheepList.iterator(); 
    //删除指定的羊
    sheep goalSheep = new sheep("慢羊羊");

    while (it.hasNext()){
        sheep s = (sheep) it.next();
        if (s.equals(goalSheep))
            it.remove();
    }
    for (sheep s : sheepList)
        System.out.println(s.name);

}

}

class animal{
public String name = "动物";
}

class sheep extends animal{
public String name;

private String head;
private String froot;

public sheep(String name){
    this.name = name;
    super.name = name;
}

public int hashCode(){
    final int prime = 31;
    int result = 1;
    result = prime * result + ((name == null) ? 0:name.hashCode());
    return result;
}
public boolean equals(Object obj){
    if (this.name.equals(((sheep)obj).name)){
        return true;
    }else
        return false;
}

}

3.多线程
package cn.edu.nuc;

public class Multithreading {
public static void main(String[] args){
SubThread s1 = new SubThread("a---");
SubThread s2 = new SubThread("b---");

    SubThread1 s11= new SubThread1("c---");
    SubThread1 s12 = new SubThread1("d---");
    s1.start();
    s2.start();

    s1.run();
    s2.run();

    s11.run();
    s12.run();
}

}

//subthread 单继承thread
class SubThread extends Thread{
private String name;
public SubThread(){

}
public SubThread(String name){
    super(name);
}
/*public String name(){
    return this.name;
}*/

public void run(){
    for (int i = 0; i < 5; i ++){
        System.out .println("这是同时进行的第 " + i + " 个"+this.getName());
    }
}

}

class SubThread1 implements Runnable{
private String name;
public SubThread1(String name){
this.name = name;
}
public SubThread1(){

}
public void run(){
    for (int i = 0; i < 5; i ++)
        System.out.println("这是同时进行的第 "+ i + "个"+this.getName());
}
private String getName() {
    // TODO Auto-generated method stub
    return this.name;
}

}