• 列出一个文件夹下所有文件名
• 创建新文件
• 生成txt文件，写入指定字符串
• 使用BufferedWriter
• 使用PrintWriter
• 按行读文件
• 重命名
• 移动文件
• 依赖
• 移动文件夹，相当于覆盖
• 移动文件夹，某个文件夹，移动到另一个文件夹内
• 移动文件，把文件移动到某个文件夹下
• 移动到文件夹，自动识别操作文件还是文件夹

列出一个文件夹下所有文件名

 public void listFileOnDir(String fileDirPath) {
    File fileDir = new File(fileDirPath);
    String[] filesOnDir = fileDir.list();
    if (filesOnDir != null) {
        log.info("listFileOnDir, filesOnDir:{}", filesOnDir);
        for (String filePath : filesOnDir) {
            try {
                String fileFullPath = fileDir + "/" + filePath;
                File singleFile = new File(fileFullPath);
                log.info("listFileOnDir, singleFile: {}", singleFile);
            } catch (Exception e) {
                log.error("listFileOnDir error", e);
            }
        }
    }
}
  

创建新文件

 public void createFile(String path, String filename) throws IOException {
     File file=new File(path+"/"+filename);
     if(!file.exists())
         file.createNewFile();
}
  

生成txt文件，写入指定字符串

使用BufferedWriter

 public void writeContentToText(String fileContent, String filePath, String fileName) throws IOException {
    // 生成的文件路径
    String fullPathName = filePath + "/" + fileName;
    File file = new File(fullPathName);
    if (!file.exists()) {
        file.getParentFile().mkdirs();
    }
    file.createNewFile();
    // write 解决中文乱码问题
    // FileWriter fw = new FileWriter(file, true);
    OutputStreamWriter fw = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
    BufferedWriter bw = new BufferedWriter(fw);
    bw.write(fileContent);
    bw.flush();
    bw.close();
    fw.close();
}
  

使用PrintWriter

 public void writeContentToTextOther(String fileContent, String fileFullPath, String fileName) {
    FileOutputStream fos  = null;
    PrintWriter pw = null;
    try {
        File sendFile = new File(fileFullPath);
        if (!sendFile.exists()) {
            sendFile.createNewFile();// 创建目标文件
        }
        fos = new FileOutputStream(sendFile);
        pw = new PrintWriter(fos);
        pw.write(fileContent.toCharArray());
        pw.flush();
        fos.close();
    } catch (IOException e) {
        log.error("writer file error", e);
    } finally {
        if (pw != null) {
            pw.close();
        }
    }
}
  

按行读文件

 public void readFileOnLine(String fullFilePath) {
    try {
        File file = new File(fullFilePath);
        InputStreamReader inputReader = new InputStreamReader(new FileInputStream(file), "utf-8");
        BufferedReader bf = new BufferedReader(inputReader);
        // 按行读取字符串
        String lineContent;
        while ((lineContent = bf.readLine()) != null) {
            // TODO:按行解析读取的文件，测试是不是不同编码的文件都能解析
            log.info("readFileOnLine, lineContent:{}", lineContent);
        }
        bf.close();
        inputReader.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
  

InputStream读取出文件是字节流，InputStreamReader可以将字节流转换为字符流
new InputStreamReader时可指定编码：

 File file = new File(fullFilePath);
InputStreamReader inputReader = new InputStreamReader(new FileInputStream(file), "utf-8");
  

重命名

 public void renameFile(String oldFullFilePath, String newFullFilePath) {
    File startFile = new File(oldFullFilePath);
    File endFile = new File(newFullFilePath);
    if (startFile.renameTo(endFile)) {
        log.info("文件移动成功！目标路径: {}", endFile.getAbsolutePath());
    } else {
        log.info("文件移动失败！起始路径: {}", startFile.getAbsolutePath());
    }
}
  

移动文件

移动文件一系列操作主要用 org.apache.commons.io下的包

依赖

 <dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.7</version>
</dependency>
  

 public void moveFile(File singleFile, String changeDir, String filePathOnDir) {
    String newGenFilePath = changeDir + "/" + filePathOnDir;
    File backedGeneratedCardFile = new File(newGenFilePath);
    try {
        FileUtils.moveFile(singleFile, backedGeneratedCardFile);
    } catch (Exception e) {
        log.error("moveFile error", e);
    }
}
  

移动文件夹，相当于覆盖

 public void moveDirectory(String oldDirPath, String newDirPath) {
    File oldDir = new File(oldDirPath);
    File newDir = new File(newDirPath);
    try {
        FileUtils.moveDirectory(oldDir, newDir);
    } catch (Exception e) {
        log.error("moveDirectory error", e);
    }
}
  

移动文件夹，某个文件夹，移动到另一个文件夹内

 public void moveDirToDirectory(String oldDirPath, String newDirPath) {
    File oldDir = new File(oldDirPath);
    File newDir = new File(newDirPath);
    try {
        FileUtils.moveDirectoryToDirectory(oldDir, newDir, true);
    } catch (Exception e) {
        log.error("moveDirToDirectory error", e);
    }
}
  

移动文件，把文件移动到某个文件夹下

 public void moveFileToDirectory(String srcFilePath, String newDirPath) {
    File oldFile = new File(srcFilePath);
    File newDir = new File(newDirPath);
    try {
        FileUtils.moveFileToDirectory(oldFile, newDir, true);
    } catch (Exception e) {
        log.error("moveFileToDirectory error", e);
    }
}
  

移动到文件夹，自动识别操作文件还是文件夹

 public void moveToDirectory(String srcPath, String newDirPath) {
    File srcInfo = new File(srcPath);
    File newDir = new File(newDirPath);
    try {
        FileUtils.moveToDirectory(srcInfo, newDir, true);
    } catch (Exception e) {
        log.error("moveFileToDirectory error", e);
    }
}