Introduction
The Java.io StringWriter is the class used to write the character stream in the form of string which acts as a destination to string writer. The Java.io StringWriter is a subclass to the writer class, it overrides all the methods from writer class.
Declaration
Java.io StringWriter class is declared below:
Public class StringWriter extends Writer Fields
Java.io StringWriter class fields are:
Protected Object Lock : For synchronize operations this object is used in StringWriter.
Table
| Constructor | Description |
|---|---|
| String writer() | The function of this constructor is to create the string writer instance and used to write from the character stream. |
| String writer(int initialSize) | The function of this constructor is to create the string writer with represented size of the string buffer. |
| Method | Description |
|---|---|
| void close () | The function of this method is to close the present stream and associated to this stream, systems resources are released without any impact. |
| StringWriter append(char c) | The function of this method is to append the given character to the writer. |
| void write (Char[] cbuf, int off, int n) | By using this method it writes the data up to ‘n’ length from the output stream to an array of Characters. |
| void write (int c) | The function of this method is to write the represented character into output stream. |
| void write (String str, int off, int n) | The function of this method is to write the string up to 'n' length. |
Description
From the following classes, methods are inherited to the string writer class.
Java.io.object
Java.io.Writer
Example
Following is an example.
[java]package com.cp.io;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringWriter;
public class StringWriterDemoOne {
public static void main(String[] args) throws IOException {
char[] buff = new char[1024];
StringWriter sw = new StringWriter();
FileInputStream fis = null;
BufferedReader bufferReader = null;
try {
fis = new FileInputStream("E:/splesson.txt");
bufferReader = new BufferedReader(new InputStreamReader(fis, "UTF-8"));
int n;
while ((n = bufferReader.read(buff)) != -1) {
sw.write(buff, 0, n);
}
System.out.println(sw.toString());
} catch (IOException e) {
e.printStackTrace();
}finally{
sw.close();
bufferReader.close();
}
}
} [/java]
The E:/splesson.txt file will contain the data that Hello Java.Java IO is fun.
Output
Following is the result will be displayed.
[java]
Hello Java.Java IO is fun.
[/java]
Following is an another example to StringWriter with StringBuffer.
[java]package com.cp.io;
import java.io.StringWriter;
public class StringWriterDemoOne {
public static void main(String[] args) {
String str1 = "Hello World!";
String str2 ="\nThis is StringReader Program.";
StringWriter outputWriter = new StringWriter();
outputWriter.write(str1,0,5);
System.out.println(outputWriter.toString());
//get StringBuffer of outputWriter
StringBuffer sbuf = outputWriter.getBuffer();
//append str2 into StringBuffer
sbuf.append(str2);
System.out.println(outputWriter.toString());
}
}[/java]
StringWriter writes character stream into a StringBuffer and finally this buffer is converted into string.
Output
The result will be as follows.
[java]
Hello
Hello
This is StringReader Program.
[/java]
Key Points
- The string writer is the class used to write the character stream in the form of string which acts as a destination to string writer.
- The string writer is a subclass to the writer class, it overrides all the methods from writer class.