ough ough - 3 months ago 16
Java Question

PrintWriter vs FileWriter in Java

Are PrintWriter and FileWriter in Java the same and no matter which one to use? So far I have used both because their results are the same. Is there some special cases where it makes sense to prefer one over the other?


public static void main(String[] args) {

File fpw = new File("printwriter.txt");
File fwp = new File("filewriter.txt");
try {
PrintWriter pw = new PrintWriter(fpw);
FileWriter fw = new FileWriter(fwp);
pw.write("printwriter text\r\n");
fw.write("filewriter text\r\n");
pw.close();
fw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

Answer Source

According to coderanch.com, if we combine the answers we get:

FileWriter is the character representation of IO. That means it can be used to write characters. Internally FileWriter would use the default character set of the underlying OS and convert the characters to bytes and write it to the disk.

PrintWriter & FileWriter.

Similarities

  1. Both extend from Writer.
  2. Both are character representation classes, that means they work with characters and convert them to bytes using default charset.

Differences

  1. FileWriter throws IOException in case of any IO failure, this is a checked exception.
  2. None of the PrintWriter methods throws IOException , instead they set a boolean flag which can be obtained using checkError().
  3. PrintWriter has on optional constructor you may use to enable auto-flushing when specific methods are called. No such option exists in FileWriter.
  4. When writing to files, FileWriter has an optional constructor which allows it to append to the existing file when the "write()" method is called.

Difference between PrintStream and OutputStream: Similar to above explanation, just replace character with byte.

PrintWriter has following methods :

close()
flush()
format()
printf()
print()
println()
write()

and constructors are :

File (as of Java 5)
String (as of Java 5)
OutputStream
Writer

while FileWriter having following methods :

close()
flush()
write()

and constructors are :

File
String 

Link: http://www.coderanch.com/t/418148/java-programmer-SCJP/certification/Information-PrintWriter-FileWriter