Java StringReader class

In this tutorial, we will learn about Java StringReader and its methods with the help of examples.

The StringReader class in the java.io package can be used to read data from a string (character by character).

It inherits from the abstract class Reader.

Note: In StringReader, the specified string acts as the source from which characters are read separately.

create a StringReader

To create a StringReader, we must first import the java.io.StringReader package. After importing the package, we can create the string reader.

//create a StringReader
StringReader input = new StringReader(String data);

Here, we create a StringReader that reads characters from the specified string named data.

StringReader methods

The StringReader class provides implementations for different methods in the Reader class.

read() method

• read()} - Read a single character from the string reader

• read(char[] array)　 - Read characters from the reader and store them in the specified array

• read(char[] array, int start, int length) - Read an equal number of characters from the reader and store them in the specified array starting from the start position

Example: Java StringReader

import java.io.StringReader;
public class Main {
　　public static void main(String[] args) {
　　　　String data = "This is the text read from StringReader.";
　　　　//create a character array
　　　　char[] array = new char[100];
　　　　try {
　　　　　　//create a StringReader
　　　　　　StringReader input = new StringReader(data);
　　　　　　//using the read method
　　　　　　input.read(array);
　　　　　　System.out.println("Reading data from a string:");
　　　　　　System.out.println(array);
　　　　　　input.close();
　　　　}
　　　　catch(Exception e) {
　　　　　　e.getStackTrace();
　　　　}
　　}
}

Output Result

Reading data from a string:
This is the text read from StringReader.

In the above example, we created a string reader named input. The string reader is linked to the string data (data).

String data = "This is a text in the string.";
StringReader input = new StringReader(data);

To read data from a string, we use the read() method.

Here, the method reads characters from the reader and stores them in the specified array.

skip() method

To discard and skip a specified number of characters, you can use the skip() method. For example

import java.io.StringReader;
public class Main {
　　public static void main(String[] args) {
　　　　String data = "This is the text read from StringReader";
　　　　System.out.println("Original data: ",　+　data);
　　　　//create a character array
　　　　char[] array = new char[100];
　　　　try {
　　　　　　//create a StringReader
　　　　　　StringReader input = new StringReader(data);
　　　　　　//using the skip() method
　　　　　　input.skip(5);
　　　　　　//using the read method
　　　　　　input.read(array);
　　　　　　System.out.println("Skip ",5the data after the character: ");
　　　　　　System.out.println(array);
　　　　　　input.close();
　　　　}
　　　　catch(Exception e) {
　　　　　　e.getStackTrace();
　　　　}
　　}
}

Output Result

Original Data: This is the text read from the StringReader
Skip5characters after data:
is the text read from the StringReader

In the above example, we use the skip() method to skip5characters. Therefore, the characters 'T', 'h', 'i', 's', and ' ' are skipped from the original string reader.

close() Method

To close the string reader, we can use the close() method. After calling the close() method, we will not be able to use the reader to read data from the string.

Other Methods of StringReader