Java - StringWriter write(String str) method

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Description

The Java StringWriter write(String str) method writes the given string.

Declaration

Following is the declaration for java.io.StringWriter.write(String str) method.

public void write(String str)

Parameters

• str − String to be written.

Return Value

This method does not return a value.

Exception

NA

Example - Usage of StringWriter write(String str) method

The following example shows the usage of StringWriter write(String str) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) {
      String s = "Hello";

      // create a new writer
      StringWriter sw = new StringWriter();

      // write strings
      sw.write(s);
      sw.write(" World");

      // print result by converting to string
      System.out.println("" + sw.toString());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Hello World

Example - Converting written text to String

The following example shows the usage of StringWriter write(String str) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) throws Exception {
      StringWriter writer = new StringWriter();

      // Writing a full string
      writer.write("Hello, ");
      writer.write("Linux World!");

      String result = writer.toString();
      System.out.println(result);  // Output: Hello, Linux World!
   }
}

Output

Let us compile and run the above program, this will produce the following result−

Hello, Linux World!

Explanation

• A StringWriter is created.

• write(String str) is called twice −

  • First with "Hello, "

  • Then with "Linux World!"

• The strings are concatenated in the buffer.

• toString() returns the combined string: "Hello, Linux World!".

Example - Writing Part of a String (Substring)

The following example shows the usage of StringWriter write(String str) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) {
      StringWriter writer = new StringWriter();
      String text = "Welcome to Java Programming!";

      // Writing a substring (from index 11, length 4)
      writer.write(text, 11, 4);  // "Java"

      String result = writer.toString();
      System.out.println(result);  // Output: Java
   }
}

Output

Let us compile and run the above program, this will produce the following result−

Java

Explanation

• The original string is "Welcome to Java Programming!".

• write(text, 11, 4) writes−

  • From index 11 ('J' in "Java").

  • 4 characters → "Java".

• The buffer contains only "Java".