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Commit330f861

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Merge pull request#6 from coderolls/blog/read-file-using-bufferreader
Add new blogpost on BufferReader
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---
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layout:post
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title:"How To Read File Using BufferReader In Java?"
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author:gaurav
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image:assets/images/2021-01-03/read-file-using-bufferreader.png
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categories:[Java, Java File IO]
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description:"In this article we will see how to read a file using the `BufferReader` class in Java."
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---
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In this article we will see how to read a file using the`BufferReader`class in Java.
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`BufferReader` class reads text from a character-input stream. Because of buffering characters it provides an efficient way to read characters, arrays, and lines.
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`BufferReader` provides two important methods to read from the file. i.e`read()` and`readLine()`.
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You can specify the bufferSize in`BufferReader`constructer. But as[motioned in the docs](https://docs.oracle.com/javase/8/docs/api/java/io/BufferedReader.html),
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>The default is large enough for most purposes.
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##BufferReader`read()` method
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`BufferReader``read()` method reads a single character. IT returns the`int` representation of the char in range of 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached.
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We can cast`int` value returned by`read()` method to`char` to get the character value.
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I have given an example to read a file character by character using the`read()` method of the`BufferReader` class
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```java
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packagecom.coderolls;
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importjava.io.*;
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/**
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* A java program to read file character by character using the
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* read() method of the BufferReader Class.
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*
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*@author Gaurav Kukade at coderolls.com
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*/
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publicclassBufferReaderReadMethodExample {
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publicstaticvoidmain(String[]args) {
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BufferedReader bufferedReader=null;
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try {
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bufferedReader=newBufferedReader(newFileReader("F:\\sample-text.txt"));
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int i;
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//read each character using read() method and print it
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while((i=bufferedReader.read())!=-1){
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System.out.print((char)i);
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}
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}catch (IOException e) {
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e.printStackTrace();
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}finally {
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try {
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bufferedReader.close();
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}catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
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}
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```
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Output
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```
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Welcome to coderolls.com!
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```
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See[this example on GitHub](https://github.com/coderolls/blogpost-coding-examples/blob/main/java-files-io/BufferReaderReadMethodExample.java).
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##BufferReader`readLine()` method
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As specified in the name, this method reads a line of text.
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A line is considered to be terminated by any one of a line feed ('\n') or a carriage return ('\r').
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The`readLine()` method returns the content of a line as string except the line terminating character (i.e.`\n` or`\r`). Or it will return`null` if the end of the stream has been reached.
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I have given below an example to read file line by line using the`readLine()` method
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```java
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packagecom.coderolls;
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importjava.io.*;
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/**
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* A java program to read file line by line using the
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* readLine() method of the BufferReader Class.
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*
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*@author Gaurav Kukade at coderolls.com
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*
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*/
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publicclassBufferReaderReadLineMethodExample {
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publicstaticvoidmain(String[]args) {
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BufferedReader bufferedReader=null;
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try {
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bufferedReader=newBufferedReader(newFileReader("F:\\sample-text-two-lines.txt"));
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String line;
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//read each line using readLine() method and print it
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while((line= bufferedReader.readLine())!=null){
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System.out.println(line);
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}
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}catch (IOException e) {
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e.printStackTrace();
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}finally {
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try {
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bufferedReader.close();
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}catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
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}
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```
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Output
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```java
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Welcome to coderolls.com!
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Visit coderolls to read more coding tutorials!
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```
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See[this example on GitHub](https://github.com/coderolls/blogpost-coding-examples/blob/main/java-files-io/BufferReaderReadLineMethodExample.java).
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I have given below a combine example of the Java`BufferReader``read()` and`readLine()` method below
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```java
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packagecom.coderolls;
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importjava.io.*;
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publicclassBufferReaderExanple {
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publicstaticvoidmain(String[]args) {
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BufferedReader bufferedReader=null;
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try {
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bufferedReader=newBufferedReader(newFileReader("F:\\sample-text-two-lines.txt"));
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}catch (FileNotFoundException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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}
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readFileCharacterByCharacter(bufferedReader);
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readFileLineByLine(bufferedReader);
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try {
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bufferedReader.close();
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}catch (IOException e) {
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e.printStackTrace();
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}
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}
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/**
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* A method to read file content character by character using the BufferReader
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* read() method
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*
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*@param bufferedReader
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*/
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publicstaticvoidreadFileCharacterByCharacter(BufferedReaderbufferedReader) {
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try {
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int i;
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//read each character using read() method and print it
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while((i=bufferedReader.read())!=-1){
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System.out.print((char)i);
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}
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}catch (IOException e) {
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e.printStackTrace();
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}
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}
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/**
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* A method to read file content line by line using the BufferReader
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* readLine() method
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*
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*@param bufferedReader
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*/
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publicstaticvoidreadFileLineByLine(BufferedReaderbufferedReader) {
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try {
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String line;
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//read each line using readLine() method and print it
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while((line= bufferedReader.readLine())!=null){
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System.out.println(line);
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}
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}catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
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```
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See[this example on GitHub](https://github.com/coderolls/blogpost-coding-examples/blob/main/java-files-io/BufferReaderExanple.java).
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##`newBufferedReader()` method in Java 8
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In Java 1.8 and above you can get a`BufferReader` instance using the`newBufferedReader()` method of the`java.nio.file.Files` class.
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##Conclusion
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You can read file character by character using the`read()` method of the`BufferReader`Class.
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`read()` method returns an integer value, you have to cast it to`char` to get character value.
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Also, you can read file line by line using the`readLine()` method of the`BufferReader`Class
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`readLine()` methods returns the line content as string, except the line terminating character
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You can visit my[YouTube channel 'coderolls'](https://www.youtube.com/channel/UCl31HHUdQbSHOQfc9L-wo3w?view_as=subscriber?sub_confirmation=1) to find more video tutorials.
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--------------
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You can support me by[giving a cup of Coffee ☕](https://www.paypal.me/GauravKukade)
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####Related Articles
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-[8 Basic GIT Commands Every Newbie Developer Must Know](https://coderolls.com/basic-git-commands/)
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-[How To Reverse A String In Java (5 ways)](https://coderolls.com/reverse-a-string-in-java/)
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-[How To Create UUID in Java?](https://coderolls.com/create-uuid-in-java/)
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-[Learn About Java String Pool And intern() Method](https://coderolls.com/java-string-pool-and-intern-method/)
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-[How Do I Compare Strings In Java](https://coderolls.com/compare-strings-in-java/)
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-[Compare Two Strings Lexicographically In Java](https://coderolls.com/compare-two-strings-lexicographically-in-java/)
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-[Difference Between StringBuffer and StringBuilder class](https://coderolls.com/difference-between-stringbuffer-and-stringbuilder/)
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-[8 Basic GIT Commands Every Newbie Developer Must Know](https://coderolls.com/basic-git-commands/)
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-[How To Create UUID in Java?](https://coderolls.com/create-uuid-in-java/)
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