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http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html java.io.BufferedWriter Class A BufferedWriter is a Writer that buffers output, writes text to a character-output stream, buffering characters so as to provide for the efficient writing of single characters, arrays, and strings. Using a BufferedWriter can improve performance by reducing the number of times data is actually physically written to the output device. Writer sends its output immediately to the underlying character or byte stream. Unless prompt output is required, it is advisable to wrap a BufferedWriter around any Writer whose write() operations may be costly, such as FileWriters and OutputStreamWriters. A newLine() method is provided, which uses the platform's own notion of line separator as defined by the system property line.separator. Not all platforms use the newline character ('\n') to terminate lines. Calling this method to terminate each output line is therefore preferred to writing a newline character directly. A BufferedWriter has these two constructors: BufferedWriter(Writer out) Creates a buffered character-output stream that uses a default-sized output buffer. BufferedWriter(Writer out, int sz) Creates a new buffered character-output stream that uses an output buffer of the given size. The following program shows how to send output to console using java. /* Following example shows how to write String to console. */ /* java.io.BufferedWriter class Example */ /* Save with file name BufferedWriterExample.java */ import java.io.*; public class BufferedWriterExample { public static void main(String args[]) { //java.io.BufferedWriter DECLARATION java.io.BufferedWriter bw = null; //OutputStreamWriter DECLARATION OutputStreamWriter osw = null; /*WE SHOULD USE try-catch BECAUSE MOST OF THE JAVA I/O CLASES THROWS IOException */ try { String str = "This is test String for BufferedWriter."; osw = new OutputStreamWriter(System.out); bw = new BufferedWriter(osw); bw.write(str,0,str.length()); 1 http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html } catch(Exception e) { System.out.println("Error Occurred : "+e.getMessage()); } finally { //SHOULD CLOSE STREAMS FINALLY try { if(bw!=null) bw.close(); if(osw!=null) osw.close(); } catch(Exception ex) { System.out.println("Error Occurred : "+ex.getMessage()); } } } } /* Following example shows how to write String to console. */ /* java.io.BufferedWriter class Example 2*/ /* Save with file name BufferedWriterExample2.java */ import java.io.*; public class BufferedWriterExample2 { public static void main(String args[]) { //java.io.BufferedWriter DECLARATION java.io.BufferedWriter bw = null; //OutputStreamWriter DECLARATION OutputStreamWriter osw = null; /*WE SHOULD USE try-catch BECAUSE MOST OF THE JAVA I/O CLASES THROWS IOException */ try { String str = "This is test String 1 for BufferedWriter."; String str2 = "This is test String 2 for newline method in BufferedWriter."; osw = new OutputStreamWriter(System.out); bw = new BufferedWriter(osw); bw.write(str,0,str.length()); //WRITES NEW LINE CHARACTER TO OUTPUT STREAM bw.newLine(); 2 http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html bw.write(str2,0,str2.length()); } catch(Exception e) { System.out.println("Error Occurred : "+e.getMessage()); } finally { //SHOULD CLOSE STREAMS FINALLY try { if(bw!=null) bw.close(); if(osw!=null) osw.close(); } catch(Exception ex) { System.out.println("Error Occurred : "+ex.getMessage()); } } } } /* Following example shows how to read the text from file write to console. */ /* java.io.BufferedWriter class Example 3*/ /* Save with file name BufferedWriterExample3.java */ import java.io.*; public class BufferedWriterExample3 { public static void main(String args[]) { //java.io.BufferedWriter DECLARATION java.io.BufferedWriter bw = null; //OutputStreamWriter DECLARATION OutputStreamWriter osw = null; //java.io.BufferedReader DECLARATION java.io.BufferedReader br = null; //InputStreamReader DECLARATION InputStreamReader ir = null; //FileInputStream DECLARATION FileInputStream fis = null; /*WE SHOULD USE try-catch BECAUSE MOST OF THE JAVA I/O CLASES THROWS IOException */ try { int ch; osw = new OutputStreamWriter(System.out); 3 http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html bw = new BufferedWriter(osw); fis = new FileInputStream("BufferedWriterExample3.java"); ir = new InputStreamReader(fis); br = new BufferedReader(ir); while((ch = br.read()) != -1) { bw.write(ch); } } catch(Exception e) { System.out.println("Error Occurred : "+e.getMessage()); } finally { //SHOULD CLOSE STREAMS FINALLY try { if(bw!=null) bw.close(); if(osw!=null) osw.close(); if(br!=null) br.close(); if(ir!=null) ir.close(); if(fis!=null) fis.close(); } catch(Exception ex) { System.out.println("Error Occurred : "+ex.getMessage()); } } } } /* Following example shows how to read total bytes from file into array and write to console. */ /* java.io.BufferedWriter class Example 4*/ /* Save with file name BufferedWriterExample4.java */ import java.io.*; public class BufferedWriterExample4 { public static void main(String args[]) { //java.io.BufferedWriter DECLARATION java.io.BufferedWriter bw = null; 4 http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html //OutputStreamWriter DECLARATION OutputStreamWriter osw = null; //java.io.BufferedReader DECLARATION java.io.BufferedReader br = null; //InputStreamReader DECLARATION InputStreamReader ir = null; //FileInputStream DECLARATION FileInputStream fis = null; //ARRAY TO READ BYTES char charbuff[] = null; /*WE SHOULD USE try-catch BECAUSE MOST OF THE JAVA I/O CLASES THROWS IOException */ try { int ch; osw = new OutputStreamWriter(System.out); bw = new BufferedWriter(osw); fis = new FileInputStream("BufferedWriterExample4.java"); ir = new InputStreamReader(fis); br = new BufferedReader(ir); //GET THE AVAILABLE BYTES FROM InputReader AND CREATES ARRAY charbuff = new char[fis.available()]; //READ TOTAL BYTES FROM FILE br.read(charbuff, 0,fis.available()); bw.write(charbuff, 0,charbuff.length); } catch(Exception e) { System.out.println("Error Occurred : "+e.getMessage()); } finally { //SHOULD CLOSE STREAMS FINALLY try { //RELEASE ARRAY MEMORY charbuff = null; if(bw!=null) bw.close(); if(osw!=null) osw.close(); if(br!=null) br.close(); 5 http://www.hudatutorials.com Download link: http://www.hudatutorials.com/ht/java/io/bufferedwriter.html if(ir!=null) ir.close(); if(fis!=null) fis.close(); } catch(Exception ex) { System.out.println("Error Occurred : "+ex.getMessage()); } } } } 6