Reader read() in Java

read(): This method is available in the java.io.Reader class of Java.

Syntax:

int java.io.Reader.read() throws IOException

This method reads a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached.

Parameters: NA

Returns: The character read, as an integer in the range 0 to 65535(0x00-0xffff), or -1 if the end of the stream has been reached.

Throws:

IOException - If an I/O error occurs

Approach 1: When no exception

Java

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

public class Readerread {
    public static void main(String[] args) throws IOException {

        Reader reader = new StringReader("HELLO");

        System.out.println(reader.read());
        reader.close();

    }
}

Output:

72


Approach 2: IOException 

Java

package com.Reader;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

public class Readerread {
    public static void main(String[] args) throws IOException {

        Reader reader = new StringReader("HELLO");

        reader.close();
        System.out.println(reader.read());

    }
}

Output:

Exception in thread "main" java.io.IOException: Stream closed at java.base/java.io.StringReader.ensureOpen(StringReader.java:56) at java.base/java.io.StringReader.read(StringReader.java:69) at com.Reader.Readerread.main(Readerread.java:13)


Some other methods of Reader

close()This method closes the stream and releases any system resources associated with it.

mark(int)This method marks the present position in the stream.

markSupported()This method tells whether this stream supports the mark() operation. 

Reader.nullReader()This method returns a new Reader that reads no characters.

read()This method reads a single character.

read(char[])This method reads characters into an array.

read(CharBuffer)This method attempts to read characters into the specified character buffer.

read(char[], int, int)This method reads characters into a portion of an array.

ready()This method tells whether this stream is ready to be read.

reset()This method resets the stream.

skip(long)This method skips characters.

transferTo(Writer)This method reads all characters from this reader and writes the characters to the given writer in the order that they are read.

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