Java 文件操作demo（一）

package com.example.yan.java文件写入;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
public class Main {
    public static void main(String[] args)  {
        try {
            BufferedWriter out = new BufferedWriter(new FileWriter("nowcoder.txt"));
            out.write("牛客教程");
            out.close();
            System.out.println("文件创建成功！");
        } catch (IOException e) {
        }
    }
}

package com.example.yan.java文件写入;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class Main1 {
    public static void main(String[] args)  {
        try {
            BufferedReader in = new BufferedReader(new FileReader("C:\\Users\\75763\\Desktop\\test.log"));
            String str;
            while ((str = in.readLine()) != null) {
                System.out.println(str);
            }
            System.out.println(str);
        } catch (IOException e) {
        }
    }

package com.example.yan.java文件写入;
import java.io.File;
public class Main2 {
        public static void main(String[] args) {
            try {
                File file = new File("C:\\Users\\75763\\Desktop\\test.log");
                if (file.delete()) {
                    System.out.println(file.getName() + " 文件已被删除！");
                } else {
                    System.out.println("文件删除失败！");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
}

package com.example.yan.java文件写入;
import java.io.*;
public class Main4 {
    public static void main(String[] args) throws Exception {
        BufferedWriter out1 = new BufferedWriter(new FileWriter("srcfile"));
        out1.write("string to be copied\n");
        out1.close();
        InputStream in = new FileInputStream(new File("srcfile"));
        OutputStream out = new FileOutputStream
                (new File("destnfile"));
        byte[] buf = new byte[1024];
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
        BufferedReader in1 = new BufferedReader(new FileReader("destnfile"));
        String str;
        while ((str = in1.readLine()) != null) {
            System.out.println(str);
        }
        in1.close();
    }
}