Java IO实战操作(一)

/** * 创建一个新文件 */ public void NewFiles() { File file = new File("D:\\IO.txt"); try { file.createNewFile(); System.out.println("文件创建成功!"); } catch (IOException e) { e.printStackTrace(); } } /** * File类的两个常量\ ;考虑到跨平台性所以推荐使用下面的常量 */ public void FinalNum() { System.out.println(File.separator); System.out.println(File.pathSeparator); } /** * 文件的删除 */ public void delete() { String fileName = "D:" + File.separator + "IO.txt"; File file = new File(fileName); if (file.exists()) { file.delete(); } else { System.out.println("文件不存在"); } } /** * 创建一个文件夹 */ public void Mkdir() { String fileName = "D:" + File.separator + "IO"; File file = new File(fileName); file.mkdir(); } /** * 列出指定目录下面的全部文件(包括隐藏文件) */ public void FileView() { String fileName = "D:" + File.separator; File file = new File(fileName); String[] str = file.list(); File[] fileStr = file.listFiles();// 返回完整路径 for (int i = 0; i < str.length; i++) { System.out.println(str[i]); } } /** * 判定一个指定的路径是否为目录 */ public void TFFile() { String fileName = "D:" + File.separator; File file = new File(fileName); if (file.isDirectory()) { System.out.println("True"); } else { System.out.println("False"); } } /** * 列出指定目录的全部内容 */ public void ViewOver(){ class print{ public void Show(File f){ if(f!=null){ if(f.isDirectory()){ File[] fileArray=f.listFiles(); if(fileArray!=null){ for(int i=0;i<fileArray.length;i++){ // 递归调用 Show(fileArray[i]); }}} }}} String fileName="D:"+File.separator; File file=new File(fileName); print pr=new print(); pr.Show(file);} /** * 使用RandomAccessFile写入文件 * @throws IOException */ public void InserNum() throws IOException { String fileName = "D:" + File.separator + "IO.txt"; File file = new File(fileName); RandomAccessFile demo = new RandomAccessFile(file, "rw"); demo.writeBytes("我的天啊。。"); demo.writeInt(12); demo.writeBoolean(true); demo.writeChar('A'); demo.writeFloat(1.2f); demo.writeDouble(12.33); demo.close(); // 如果你此时打开hello。txt查看的话，会发现那是乱码 } /** * 向文件中写入字符串 * @throws IOException */ public void StringNum() throws IOException { String fileName = "D:" + File.separator + "IO.txt"; File file = new File(fileName); OutputStream out = new FileOutputStream(file); String str = "你好ACCP"; byte[] Bstr = str.getBytes(); out.write(Bstr); out.close(); } /** * 一个字节一个字节的写入 * @throws IOException */ public void OneStringNum() throws IOException { String fileName = "D:" + File.separator + "IO.txt"; File file = new File(fileName); OutputStream out = new FileOutputStream(file); String str = "你好!!"; byte[] Bbyte = str.getBytes(); for (int i = 0; i < Bbyte.length; i++) { out.write(Bbyte[i]); } out.close(); }