io包的综合运用

package io;import java.io.File;import java.io.FileFilter;import java.io.FileReader;import java.io.IOException;import java.io.RandomAccessFile;public class RandomAccessFileDemo implements FileFilter{public static void main(String[] args){RandomAccessFileDemo r = new RandomAccessFileDemo();File file1 = new File("G:\\a.txt");// try// {// r.Read(file1);// }// catch (IOException e)// {// // TODO Auto-generated catch block// e.printStackTrace();// }//// try// {// r.cut(file1);// }// catch (IOException e)// {// // TODO Auto-generated catch block// e.printStackTrace();// }// File f = new File("G:\\");// try// {// r.connectFile(f.listFiles());//// }// catch (IOException e)// {// // TODO Auto-generated catch block// e.printStackTrace();// }try{r.compress(file1);}catch (IOException e){// TODO Auto-generated catch blocke.printStackTrace();}System.out.println("ok");}/*** 读文件* * @param file* @throws IOException*/public void Read(File file) throws IOException{RandomAccessFile raf = new RandomAccessFile(file, "r");byte b;b = raf.readByte();System.out.println((char) b);}/*** 把一个文件拆分为每个大小为16k小的文件* * @param file* @throws IOException*/public void cut(File file) throws IOException{RandomAccessFile raf = new RandomAccessFile(file, "r");// 获取文件的长度int n = (int) raf.length();for (int i = 0; i < n / (16 * 1024); i++){// 从file中读取16k然后创建一个新的文件，写入新建的文件中byte[] bt = new byte[16 * 1024];raf.read(bt);File newFile = new File("G:\\" + i + "CutFile.txt");newFile.createNewFile();RandomAccessFile rafWrite = new RandomAccessFile(newFile, "rw");rafWrite.write(bt);}}/*** 删除文件名以a.txt结束的文件*/public void del(){File file = new File("G:\\");File f[] = file.listFiles();for (File file2 : f){if (this.accept(file2))file2.delete();}}/*** 拼接文件* * @param file* @throws IOException*/public void connectFile(File[] file) throws IOException{RandomAccessFile raf1, raf2;File connect = new File("G:\\connect.txt");connect.createNewFile();raf2 = new RandomAccessFile(connect, "rw");StringBuffer sbf = new StringBuffer();for (File file2 : file){if (accept(file2)){raf1 = new RandomAccessFile(file2, "rw");for (int i = 0; i < raf1.length() / 2; i++){sbf.append(raf1.readChar());}}}raf2.writeChars(new String(sbf));}/*** 压缩文件,剔除空格* * @param file* @throws IOException*/public void compress(File file) throws IOException{/* 还有问题，无法到达目的 */FileReader fr = new FileReader(file);RandomAccessFile raf = new RandomAccessFile(file, "r");char[] ch = new char[(int) raf.length() / 2];fr.read(ch);StringBuffer sbf = new StringBuffer();for (int i = 0; i < ch.length; i++){if (ch[i] != ' ')sbf.append(ch[i]);}File f = new File("G:\\compressFile.txt");f.createNewFile();RandomAccessFile raf1 = new RandomAccessFile(f, "rw");raf1.writeChars(new String(sbf));}/*** */public boolean accept(File pathname){if (pathname.getName().endsWith("File.txt"))return true;elsereturn false;}}

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