输入输出流

.createNewFile()  创建文件

---

//创建文件
public class t {
    public static void main(String[] args) {
            
        File f = new File("D:/20161229/3.txt");
        try {
            f.createNewFile();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

 .mkdir   创建文件

---

//创建文件夹
package hibernate;

import java.io.File;
import java.io.IOException;

public class t {
    public static void main(String[] args) {
            
        File f = new File("D:/20161229/10010");
        try {
            f.mkdir();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

//删除
public class t {
    public static void main(String[] args) {
            
        File f = new File("D:/20161229/10010");
        try {
            f.delete();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

 

//读出D盘下 3.txt的内容！
public class t {
    public static void main(String[] args) {
        FileReader fi=null;
        File f = new File("D:/20161229/3.txt");
        try {
            fi = new FileReader(f);
            try {
                int  i=fi.read();
                while(i!=-1){
                    System.out.print((char)i);
                    i=fi.read();
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            if(fi!=null){
                try {
                    fi.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                }
            
        }
    }
}