Java IO的常用方法

矫情吗；* 2023-07-04 15:59 11阅读 0赞

# 文件复制 #

## 1 使用IO复制 ##

public static void ioCopy(String pathIn,String pathOut) throws IOException { 
        BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(pathIn));
        BufferedOutputStream outputStream = new BufferedOutputStream(new FileOutputStream(pathOut));
        int len = 0;
        byte[] buffer = new byte[1024];
        while ((len = inputStream.read(buffer)) != -1) { 
            outputStream.write(buffer,0,len);
        }
        inputStream.close();
        outputStream.close();
    }

## 2 使用NIO复制 ##

public static void channelCopy(String pathIn, String pathOut) throws IOException { 
        FileChannel fcIn = new FileInputStream(pathIn).getChannel(),
                fcOut = new FileOutputStream(pathOut).getChannel();
        fcIn.transferTo(0, fcIn.size(), fcOut);
        fcIn.close();
        fcOut.close();
    }

# 向文件中写入字符 #

## 1 用Writer向文件中写入字符串 ##

/** * @param content * @param path * @return void * @desc 用Writer向文件中写入字符串 * @method stringToFileByWriter * @author YulinChen * @date 2020/2/13 20:12 */
    public static void stringToFileByWriter(String content, String path) throws IOException { 
       PrintWriter writer = new PrintWriter(new File(path));
       writer.print(content);
       writer.close();
    }

## 2 用Channel向文件中写入字符串 ##

/** * @param content * @param path * @return void * @desc 用Channel向文件中写入字符串 * @method stringToFileByChannel * @author YulinChen * @date 2020/2/13 20:12 */
    public static void stringToFileByChannel(String content, String path) throws IOException { 
       FileChannel channel = new FileOutputStream(path).getChannel();
       //FileChannel channel = new RandomAccessFile(path, "rw").getChannel();
       channel.write(ByteBuffer.wrap(content.getBytes("UTF-8")));
       channel.close();
    }

# 从输入中获取字符串 #

## 1 从流中获取字符串 ##

/** * @param in 输入流 * @return java.lang.String * @desc 从流中获取字符串 * @method getString * @author YulinChen * @date 2020/2/13 19:49 */
    public static String getString(InputStream in) throws IOException { 
       BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
       StringBuilder sb = new StringBuilder();
       for (String line = reader.readLine(); line != null; line = reader.readLine()) { 
           sb.append(line).append("\n");
       }
       reader.close();
       return sb.toString();
    }

## 2 从Channel中获取字符串 ##

中文乱码，不推荐