Java file operation related examples
import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; public class FileOperation { public static void main(String[] args) { // create a new directory File folderPath = new File("D:\\ReadFileTest\\FileOperation"); try { if (!folderPath.exists()) { folderPath.mkdir(); // create a new directory } } catch (Exception e) { System.out.println("Error creating new directory"); e.printStackTrace (); } // create a new file File filePath = new File("D:\\ReadFileTest\\FileOperation\\FileOperation.txt"); try { if (!filePath.exists()) { filePath.createNewFile(); // create a new file } } catch (Exception e) { System.out.println("Error creating new file"); e.printStackTrace (); } // // Delete Files // File delFilePath = new // File("D:\\ReadFileTest\\FileOperation\\FileOperation.txt"); // try { // delFilePath.delete(); // } catch (Exception e) { // System.out.println("Error deleting file"); // e.printStackTrace (); // } // // Delete the empty folder (the folder will not be deleted if it is not empty) // File delFolderPath = new File("D:\\ReadFileTest\\FileOperation"); // try { // delFolderPath.delete(); // delete empty folders // } catch (Exception e) { // System.out.println("Error deleting folder"); // e.printStackTrace (); // } // // Delete all files (folders) under a folder // File delfile = new File("D:\\ReadFileTest\\FileOperation"); // File[] files = delfile.listFiles(); // System.out.println(files.length); // for (int i = 0; i < files.length; i++) { // if (!files[i].isDirectory()) { // files[i].delete(); // } // } // FileWriter writes the file (direct write without buffering) FileWriter fileWriter = null; try { fileWriter = new FileWriter(filePath); fileWriter.write("test2"); fileWriter.close(); } catch (IOException e) { System.out.println("Error writing file"); e.printStackTrace (); } finally { if (fileWriter != null) { try { fileWriter.close(); } catch (IOException e) { e.printStackTrace (); } } } // FileReader reads the file (can't read line by line, can only read with one or more characters specified) FileReader fileReader = null; try { fileReader = new FileReader(filePath); char[] cbuf = new char[10]; try { fileReader.read(cbuf); } catch (IOException e) { e.printStackTrace (); } System.out.println("cbuf == " + cbuf[0]); // "t" } catch (FileNotFoundException e) { e.printStackTrace (); } finally { try { fileReader.close(); } catch (IOException e) { e.printStackTrace (); } } // BufferedReader reads the file (can read line by line, only one or more characters can be read) (with a buffer of 8192 characters) (read data in the form of a character stream) try { fileReader = new FileReader(filePath); } catch (FileNotFoundException e1) { e1.printStackTrace(); } BufferedReader bufferedReader = new BufferedReader(fileReader); String readerValue; try { while (true) { readerValue = bufferedReader.readLine(); if (readerValue == null) { break; } System.out.println("readerValue == " + readerValue); } } catch (IOException e) { e.printStackTrace (); } finally { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace (); } } // BufferedWriter reads the file (can't read line by line, can only read with one or more characters) (with a buffer of 8192 characters) try { fileWriter = new FileWriter(filePath); } catch (IOException e) { e.printStackTrace (); } BufferedWriter bufferedWriter = new BufferedWriter(fileWriter); try { bufferedWriter.write("hello world !"); bufferedWriter.newLine(); bufferedWriter.newLine(); bufferedWriter.write("!hello world !"); bufferedWriter.write("!hello world !"); // Use the methods in the buffer to flush the data to the destination file. bufferedWriter.flush(); // Close the buffer and close the fw stream object bufferedWriter.close(); } catch (IOException e) { e.printStackTrace (); } // FileInputStream reads the file (reads data in the form of a byte stream) FileInputStream fileInputStream = null; try { fileInputStream = new FileInputStream(filePath); try { int readData = fileInputStream.read(); System.out.println("readData == " + readData); byte[] b = new byte[2]; fileInputStream.read(b); System.out.println("b == " + b[0]); } catch (IOException e) { e.printStackTrace (); } } catch (FileNotFoundException e) { e.printStackTrace (); } finally { try { fileInputStream.close(); } catch (IOException e) { e.printStackTrace (); } } // FileOutputStream writes files (writes data in the form of byte streams) FileOutputStream fileOutputStream = null; try { fileOutputStream = new FileOutputStream(filePath); byte[] buf = new byte[] { 96, 0x77, 96 }; try { fileOutputStream.write(buf); } catch (IOException e) { e.printStackTrace (); } } catch (FileNotFoundException e) { e.printStackTrace (); } finally { try { fileOutputStream.close(); } catch (IOException e) { e.printStackTrace (); } } // InputStreamReader byte stream to character stream conversion InputStreamReader inputStreamReader = null; try { fileInputStream = new FileInputStream(filePath); } catch (FileNotFoundException e) { e.printStackTrace (); } inputStreamReader = new InputStreamReader(fileInputStream); char[] charBuf = new char[10]; try { inputStreamReader.read(charBuf); System.out.println("charBuf = " + charBuf[0]); } catch (IOException e) { e.printStackTrace (); } finally { try { inputStreamReader.close(); } catch (IOException e) { e.printStackTrace (); } } // OutputStreamWriter byte stream to character stream conversion OutputStreamWriter outputStreamWriter = null; try { fileOutputStream = new FileOutputStream(filePath); } catch (FileNotFoundException e) { e.printStackTrace (); } outputStreamWriter = new OutputStreamWriter(fileOutputStream); try { outputStreamWriter.write("OutputStreamWriter"); } catch (IOException e) { e.printStackTrace (); } finally { try { outputStreamWriter.close(); } catch (IOException e) { e.printStackTrace (); } } } }
Reference text: http://www.cnblogs.com/chen111/archive/2012/06/16/2551997.html
Reference text: http://uujava0322.iteye.com/blog/1045876
Reference text: http://blog .csdn.net/miyuki0424/article/details/307904
Reference text: http://xyiyy.iteye.com/blog/361476
Reference text: http://blog.csdn.net/liuhenghui5201/article/details/8279557
Reference text : http://blog.sina.com.cn/s/blog_70e5bf6e0101dwsd.html
Reference text: http://blog.csdn.net/liuhenghui5201/article/details/8292552