StringWriter append(CharSequence, int, int) in Java

append(CharSequence, int, int): This method is available in the java.io.StringWriter class of Java.

Syntax:

StringWriter java.io.StringWriter.append(CharSequence csq, int start, int end)

This method takes three arguments. This method appends a subsequence of the specified character sequence to this writer.

Parameters: Three parameters are required for this method.

csq: The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".

start: The index of the first character in the subsequence.

end: The index of the character following the last character in the subsequence.

Returns: This writer.

Throws:

1. IndexOutOfBoundsException - If the start or end is negative, the start is greater than the end, or the end is greater than csq.length().

Approach 1: When no exception

Java

import java.io.StringWriter;

public class StringWriterappend3 {
    public static void main(String[] args) {

        StringWriter stringWriter = new StringWriter();

        CharSequence csq = new String("HELLO JAVA");
        int start = 0, end = 4;
        stringWriter.append(csq, start, end);

        System.out.println("Successfully appended");
    }
}

Output:

Successfully appended

Approach 2: IndexOutOfBoundsException 

Java

package com.StringWriter;

import java.io.StringWriter;

public class StringWriterappend3 {
    public static void main(String[] args) {

        StringWriter stringWriter = new StringWriter();

        CharSequence csq = new String("HELLO JAVA");
        int start = 0, end = 14;
        stringWriter.append(csq, start, end);

        System.out.println("Successfully appended");
    }
}

Output:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: begin 0, end 14, length 10
	at java.base/java.lang.String.checkBoundsBeginEnd(String.java:3734)
	at java.base/java.lang.String.substring(String.java:1903)
	at java.base/java.lang.String.subSequence(String.java:1942)
	at java.base/java.io.StringWriter.append(StringWriter.java:190)
	at com.StringWriter.StringWriterappend3.main(StringWriterappend3.java:12)

Some other methods of StringWriter

append(char): This method appends the specified character to this writer.

append(CharSequence): This method appends the specified character sequence to this writer.

append(CharSequence, int, int): This method appends a subsequence of the specified character sequence to this writer.

close(): This method closes a StringWriter.

flush(): This method flushes the stream.

getBuffer(): This method returns the string buffer itself.

StringWriter(): This method creates a new string writer using the default initial string buffer size.

StringWriter(int): This method creates a new string writer using the specified initial string buffer size.

toString(): This method returns the buffer's current value as a string.

write(int): This method writes a single character.

write(String): This method writes a string.

write(char[], int, int): This method writes a portion of an array of characters.

write(String, int, int): This method writes a portion of a string.