Difference Betwixt Filereader Vs Fileinputstream Inwards Java?

Even though both FileReader in addition to FileInputStream are used to read information from a file inwards Java, they are quite a different. The primary divergence betwixt the FileReader in addition to FileInputStream is that i read information from character stream piece other read information from a byte stream. The FileReader automatically converts the raw bytes into grapheme past times using platform's default grapheme encoding. This way you lot should utilization this shape if you lot are reading from a text file which has same grapheme encoding every bit the default one. If you lot move on to read a text file encoded inwards unlike grapheme encoding hence you lot should utilization InputStreamReader with specified grapheme encoding. An InputStreamReader is a span betwixt byte current in addition to grapheme current in addition to tin accept a FileInputStream every bit a source. Though, it's worth remembering that it caches the character encoding which way you lot cannot alter the encoding system programmatically.


As per my recruitment experience, I own got frequently constitute Java developers skilful on multi-threading, collections in addition to basics but fare actually pitiable on Java IO. They fighting to respond questions similar channel vs buffer, byte vs grapheme or IO vs NIO. If you lot inquire them to write code, they never grip the exception, never closed the file in addition to hardly write production character code. An interview is a house to write your best code.




Brushing upward your IO skills past times reading Core Java for Really Impatient is every bit good a skilful idea, every bit i argue of lacking Java IO cognition is the lack of practice. This book, non solely explains things good but every bit good laissez passer on you lot lots of exercises to exercise well.

Differences betwixt FileReader in addition to FileInputStream

Here are a couplet of key differences betwixt a FileReader in addition to a FileInputStream inwards Java:

1) The get-go divergence is inwards their type hierarchy, FileReader extends from Reader shape piece FileInputStream is descendent of InputStream class.

2) The minute divergence is inwards their purpose. The FileReader is meant for reading text information piece FileInputStream is for reading binary data.

3) The diverse overloaded read() method of FileReader tin read i grapheme at a fourth dimension or multiple characters into an array piece read() method of FileInputStream tin read i byte at a fourth dimension or multiple bytes inwards a byte array.

Here is a prissy slide which explains the divergence betwixt FileReader in addition to FileInputStream quite well:

Java Program to Read File using FileReader vs FileInpustStream

Let's come across an instance to acquire how to utilization both FileReader in addition to FileInputStream classes to read information from text file. Remember, FileReader reads grapheme piece FileInputStream reads bytes. In this program, I own got only read the information from the manifest.mf file which is a text file.

import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.logging.Level; import java.util.logging.Logger;   /**  * Java Program to demonstrate divergence betwixt  * FileReader in addition to FileInputStream inwards Java  *  * @author WINDOWS 8  */ public class IteratorRemoveTest {      public static void main(String args[]) throws IOException {                  // reading information using FileReader         System.out.println("Reding text file using FileReader");         try {             FileReader fr = new FileReader("manifest.mf");             int i = fr.read();                          while(i != -1){                 System.out.print((char)i);                 i = fr.read();             }                     } catch (FileNotFoundException ex) {             Logger.getLogger(IteratorRemoveTest.class.getName()).log(Level.SEVERE, null, ex);         }                           // reading information using FileInpustStream         System.out.println("Reding text file using FileInputStream");         try {                          FileInputStream fis = new FileInputStream("manifest.mf");             int b = fis.read();                          while(b != -1){                 System.out.print(b);                 b = fis.read();             }                      } catch (FileNotFoundException ex) {             Logger.getLogger(IteratorRemoveTest.class.getName()).log(Level.SEVERE, null, ex);         }       }  }  Output: Reding text file using FileReader Manifest-Version: 1.0 X-COMMENT: Main-Class volition hold upward added automatically past times construct  Reding text file using FileInputStream 779711010510210111511645861011141151051111105832494648131088456779777769788458327797105110456710897115115321191051081083298101329710010010110032971171161111099711610599971081081213298121329811710510810013101310BUILD SUCCESSFUL (total time: 0 seconds) 

That's all on the difference betwixt FileReader in addition to FileInputStream inwards Java. So, utilization FileReader if you lot intend to read streams of grapheme in addition to utilization the FileInputSream if you lot desire to read streams of raw bytes. It's amend to utilization FileReader for reading text files because it volition accept assist of converting bytes to characters but yell back that FileReader uses the platform's default grapheme encoding. If you lot are reading a file which is encoded inwards a grapheme encoding other than the host's default char encoding hence you lot should utilization the InputStreamReader.

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