java 文件复制

Posted 2021-03-01 spp123

public class CopyText { public static void main(String[] args) { copy_1(); } public static void copy_1() { FileWriter fw = null; FileReader fr = null; try { fw = new FileWriter("demo_desc.txt"); //与已有文件关联 fr = new FileReader("demo_src.txt"); int ch = 0; while ((ch = fr.read()) != -1) { fw.write(ch); } } catch (IOException e) { throw new RuntimeException("读写失败!"); } finally { if (fr != null) { try { fr.close(); } catch (IOException e) { throw new RuntimeException("关闭流失败!"); } } if (fw != null) { try { fr.close(); } catch (IOException e) { throw new RuntimeException("关闭流失败!"); } } } } public static void copy_2() { FileWriter fw = null; FileReader fr = null; try { fw = new FileWriter("demo_desc.txt"); //与已有文件关联 fr = new FileReader("demo_src.txt"); char[] buf = new char[1024]; int num = 0; while ((num = fr.read(buf)) != -1) { fw.write(buf, 0, num); } } catch (IOException e) { throw new RuntimeException("读写失败!"); } finally { if (fr != null) { try { fr.close(); } catch (IOException e) { throw new RuntimeException("关闭流失败!"); } } if (fw != null) { try { fr.close(); } catch (IOException e) { throw new RuntimeException("关闭流失败!"); } } } } }