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Java - FileReader Class
This class inherits from the InputStreamReader class. FileReader is used for reading streams of characters.
This class has several constructors to create required objects.
Following syntax creates a new FileReader, given the File to read from.
Following syntax creates a new FileReader, given the FileDescriptor to read from.
FileReader(FileDescriptor fd)
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Following syntax creates a new FileReader, given the name of the file to read from.
FileReader(String fileName)
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Once you have FileReader object in hand then there is a list of helper methods which can be used manipulate the files.
SN | Methods with Description |
1 | public int read() throws IOException Reads a single character. Returns an int, which represents the character read. |
2 | public int read(char [] c, int offset, int len) Reads characters into an array. Returns the number of characters read. |
Example:
Following is the example to demonstrate class:
import java.io.*;
public class FileRead{
public static void main(String args[])throws IOException{
File file = new File("Hello1.txt");
// creates the file
file.createNewFile();
// creates a FileWriter Object
FileWriter writer = new FileWriter(file);
// Writes the content to the file
writer.write("This\n is\n an\n example\n");
writer.flush();
writer.close();
//Creates a FileReader Object
FileReader fr = new FileReader(file);
char [] a = new char[50];
fr.read(a); // reads the content to the array
for(char c : a)
System.out.print(c); //prints the characters one by one
fr.close();
}
}
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This would produce following result:
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