Java在文件内容后面追加内容

FileOutputStream

package com.ledao;

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

/**
 * @author LeDao
 * @company
 * @create 2022-04-02 7:29
 */
public class Test {

    public static void main(String[] args) throws IOException {
        File file = new File("C:\\Users\\LeDao\\Desktop\\1.txt");
        FileOutputStream fileOutputStream = new FileOutputStream(file, true);
        for (int i = 1; i <= 10; i++) {
            //追加内容后换行
            String content = "内容" + i + "\r\n";
            //追加内容后不换行
            //String content = "内容" + i;
            fileOutputStream.write(content.getBytes());
        }
        fileOutputStream.close();
    }
}

FileWriter

package com.ledao;

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

/**
 * @author LeDao
 * @company
 * @create 2022-04-02 7:29
 */
public class Test {

    public static void main(String[] args) throws IOException {
        File file = new File("C:\\Users\\LeDao\\Desktop\\1.txt");
        FileWriter fileWriter = new FileWriter(file, true);
        for (int i = 1; i <= 10; i++) {
            //追加内容后换行
            String content = "内容" + i + "\r\n";
            //追加内容后不换行
            //String content = "内容" + i;
            fileWriter.write(content);
        }
        fileWriter.close();
    }
}

RandomAccessFile

package com.ledao;

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

/**
 * @author LeDao
 * @company
 * @create 2022-04-02 7:29
 */
public class Test {

    public static void main(String[] args) throws IOException {
        File file = new File("C:\\Users\\LeDao\\Desktop\\1.txt");
        RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");
        long length = randomAccessFile.length();
        randomAccessFile.seek(length);
        for (int i = 1; i <= 10; i++) {
            //追加内容后换行
            //String content = "内容" + i + "\r\n";
            //追加内容后不换行
            String content = "内容" + i;
            randomAccessFile.write(content.getBytes());
        }
        randomAccessFile.close();
    }
}

使用Hutool

引入依赖

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.8.0.M2</version>
</dependency>

Java代码

下面这段代码追加的内容是换行的

package com.ledao;

import cn.hutool.core.io.file.FileAppender;

import java.io.File;

/**
 * @author LeDao
 * @company
 * @create 2022-04-02 7:29
 */
public class Test {

    public static void main(String[] args) {
        File file = new File("C:\\Users\\LeDao\\Desktop\\1.txt");
        FileAppender fileAppender = new FileAppender(file, 16, true);
        for (int i = 1; i <= 10; i++) {
            String content = "内容" + i;
            fileAppender.append(content);
        }
        fileAppender.flush();
    }
}