The listFiles() method is used to get file list from a folder. Example: package com.w3spoint; import java.io.File; import java.io.FilenameFilter; public class FilteredFileList { public static void main(String args[]){ File file = new File("D:/Test files/"); File[] files = file.listFiles(new FilenameFilter() { @Override public boolean accept(File dir, String name) { if(name.toLowerCase().endsWith(".docx")){ return true; } … Read more
The readLine() method is used to get file content line by line. The readLine() returns one line at each iteration. Example: package com.w3spoint; import java.io.BufferedReader; import java.io.FileReader; public class ReadFile { public static void main(String args[]){ String fileName = "D:/Test files/file 3.txt"; BufferedReader br = null; String strLine = ""; try { br … Read more
Example: package com.w3spoint; import java.io.FileInputStream; import java.io.InputStream; public class FileToByteArray { public static void main(String args[]){ String fileName = "D:/Test files/file 3.txt"; InputStream is = null; try { is = new FileInputStream(fileName); byte content[] = new byte[2*1024]; int readCount = 0; while((readCount = is.read(content)) > 0){ System.out.println(new String(content, 0, readCount-1)); } } catch … Read more
We need to implement FilenameFilter class and override accept() method. Example: package com.w3spoint; import java.io.File; import java.io.FilenameFilter; public class FilesFilter { public static void main(String args[]){ File file = new File("D:/Test files/"); String[] files = file.list(new FilenameFilter() { @Override public boolean accept(File dir, String name) { if(name.toLowerCase().endsWith(".txt")){ return true; } else { … Read more
The listFiles() method of File class is used to get the list of files in the folder or directory. Example: package com.w3spoint; import java.io.File; public class ListFiles { public static void main(String args[]){ File file = new File("D:/Test files/"); File[] files = file.listFiles(); for(File f: files){ System.out.println(f.getName()); } } }package com.w3spoint; import java.io.File; … Read more
The list() method of File class is used to get the list of file names in the folder or directory. Example: package com.w3spoint; import java.io.File; public class ListFileNames { public static void main(String args[]){ File file = new File("D:/Test files/"); String[] fileList = file.list(); for(String name:fileList){ System.out.println(name); } } }package com.w3spoint; import java.io.File; … Read more
Transient variable: A variable declared with transient keyword is a transient variable. It is used in serialization process to provide flexibility for excluding some variables from serialization process. A variable declared with transient keyword will not be serialized. Example: TransientExample.java import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; /** * … Read more
In java serialization is way used to convert an object into a byte stream which can be transported to any other running JVM through a network or can be persisted into disk and that object can be rebuilt again. Java provides serialization API for this. How to make a class serializable in java? To make … Read more
Example: FileCheckExample.java import java.io.File; /** * This program is used to check that file * exists or not at given location. * @author w3spoint */ class IOTest{ public void checkFileExistance(){ //Creating File object. File file = new File("F:\\New folder\\data1.txt"); if(file.exists()){ System.out.println("file exist."); }else{ System.out.println("file not exist."); } } } public class FileCheckExample { … Read more
FileReader: FileReader class is used for reading streams of characters from a file. Commonly used constructors of FileReader: 1. FileReader(File file) Creates a new FileReader, given the File to read from. 2. FileReader(String fileName) Creates a new FileReader, given the name of the file to read from. Example: FileReaderExample.java import java.io.FileReader; /** * This … Read more