Java 文本文件 读写

Use File/FileInputStream/FileOutputStream.

public void testWithFIS() throws IOException{
        File file=new File("Test.txt");
        FileInputStream fis=new FileInputStream(file);

        System.out.println("total file size:"+fis.available());

        int content;
        while((content = fis.read()) != -1){
            System.out.println((char)content);
        }

        fis.close();

    }

    public void testWithFISWrite() throws IOException{
        File file=new File("Test.txt");
        FileOutputStream fos=new FileOutputStream(file);

        for (int i = 0; i < 5; i++) {
            fos.write((int)'x');
        }

        fos.close();

    }
    

FileReader/BufferedReader

FileWriter/BufferedWriter

    public void testWithBufferReader() throws IOException{
        FileReader file=new FileReader("Test.txt");
        BufferedReader br=new BufferedReader(file);

        String currentLine;
        while((currentLine = br.readLine()) != null){
            System.out.println(currentLine);
        }

        br.close();
        file.close();
    }

    @Test
    public void testWithBufferWriter() throws IOException{
        FileWriter file=new FileWriter("Test.txt");
        BufferedWriter writer= new BufferedWriter(file);

        String currentLine="hello, this is ross";
        writer.write(currentLine);
        writer.newLine();
        writer.write("second line");
        writer.close();
        file.close();
    }