StringWriter StringWriter(int) in Java

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

Syntax:

java.io.StringWriter.StringWriter(int initialSize)

This method takes one argument. This method creates a new string writer using the specified initial string buffer size.

Parameters: One parameter is required for this method.

initialSize: The number of char values that will fit into this buffer before it is automatically expanded.

Throws:

1. IllegalArgumentException - If initialSize is negative

Approach 1: When no exception

Java

import java.io.IOException;
import java.io.StringWriter;

public class StringWriterStringWriter2 {
    public static void main(String[] args) throws IOException {

        int initialSize = 100;
        StringWriter stringWriter =
                     new StringWriter(initialSize);

        stringWriter.append("HELLO");
        System.out.println(stringWriter);
    }
}

Output:

HELLO

Approach 2: IllegalArgumentException 

Java

package com.StringWriter;

import java.io.IOException;
import java.io.StringWriter;

public class StringWriterStringWriter2 {
    public static void main(String[] args) throws IOException {

        int initialSize = -100;
        StringWriter stringWriter = 
                    new StringWriter(initialSize);

        stringWriter.append("HELLO");
        System.out.println(stringWriter);
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: Negative buffer size
	at java.base/java.io.StringWriter.<init>(StringWriter.java:67)
	at com.StringWriter.StringWriterStringWriter2.main(StringWriterStringWriter2.java:10)

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.