The ready() method of Reader Class in Java is used to check whether this Reader is ready to be read or not. It returns a boolean which states if the reader is ready.
Syntax:
public void ready()
Parameters: This method does not accepts any parameters
Return Value: This method returns a boolean value which tells if this Reader is ready to be read or not. It return true if it is ready. Else it returns false.
Exception: This method throws IOException if some error occurs while input-output.
Below methods illustrates the working of ready() method:
Program 1:
// Java program to demonstrate // Reader ready() method import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
try {
String str = "GeeksForGeeks" ;
// Create a Reader instance
Reader reader
= new StringReader(str);
// Check if the Reader is
// ready to be read using ready()
System.out.println( "Is Reader ready "
+ "to be read: "
+ reader.ready());
// Get the character
// to be read from the stream
int ch;
// Read the first 5 characters
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
for ( int i = 0 ; i < 5 ; i++) {
ch = reader.read();
System.out.println( "\nInteger value "
+ "of character read: "
+ ch);
System.out.println( "Actual "
+ "character read: "
+ ( char )ch);
}
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
} |
Is Reader ready to be read: true Integer value of character read: 71 Actual character read: G Integer value of character read: 101 Actual character read: e Integer value of character read: 101 Actual character read: e Integer value of character read: 107 Actual character read: k Integer value of character read: 115 Actual character read: s
Program 2:
// Java program to demonstrate // Reader ready() method import java.io.*;
import java.util.*;
class GFG {
public static void main(String[] args)
{
try {
String str = "GeeksForGeeks" ;
// Create a Reader instance
Reader reader
= new StringReader(str);
reader.close();
// Check if the Reader is
// ready to be read using ready()
System.out.println( "Is Reader ready "
+ "to be read: "
+ reader.ready());
// Get the character
// to be read from the stream
int ch;
// Read the first character
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
ch = reader.read();
System.out.println( "\nInteger value "
+ "of character read: "
+ ch);
System.out.println( "Actual "
+ "character read: "
+ ( char )ch);
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
} |
java.io.IOException: Stream closed
Reference: https://docs.oracle.com/javase/9/docs/api/java/io/Reader.html#ready–