//: NewIODemo.java ////////////////////////////////////////////////// // Copyright (c) Bruce Eckel, 1998 // Source code file from the book "Thinking in Java" // All rights reserved EXCEPT as allowed by the // following statements: You can freely use this file // for your own work (personal or commercial), // including modifications and distribution in // executable form only. Permission is granted to use // this file in classroom situations, including its // use in presentation materials, as long as the book // "Thinking in Java" is cited as the source. // Except in classroom situations, you cannot copy // and distribute this code; instead, the sole // distribution point is http://www.BruceEckel.com // (and official mirror sites) where it is // freely available. You cannot remove this // copyright and notice. You cannot distribute // modified versions of the source code in this // package. You cannot use this file in printed // media without the express permission of the // author. Bruce Eckel makes no representation about // the suitability of this software for any purpose. // It is provided "as is" without express or implied // warranty of any kind, including any implied // warranty of merchantability, fitness for a // particular purpose or non-infringement. The entire // risk as to the quality and performance of the // software is with you. Bruce Eckel and the // publisher shall not be liable for any damages // suffered by you or any third party as a result of // using or distributing software. In no event will // Bruce Eckel or the publisher be liable for any // lost revenue, profit, or data, or for direct, // indirect, special, consequential, incidental, or // punitive damages, however caused and regardless of // the theory of liability, arising out of the use of // or inability to use software, even if Bruce Eckel // and the publisher have been advised of the // possibility of such damages. Should the software // prove defective, you assume the cost of all // necessary servicing, repair, or correction. If you // think you've found an error, please email all // modified files with clearly commented changes to: // Bruce@EckelObjects.com. (Please use the same // address for non-code errors found in the book.) ///////////////////////////////////////////////// // Java 1.1 IO typical usage import java.io.*; public class NewIODemo { public static void main(String[] args) { try { // 1. Reading input by lines: BufferedReader in = new BufferedReader( new FileReader(args[0])); String s, s2 = new String(); while((s = in.readLine())!= null) s2 += s + "\n"; in.close(); // 1b. Reading standard input: BufferedReader stdin = new BufferedReader( new InputStreamReader(System.in)); System.out.print("Enter a line:"); System.out.println(stdin.readLine()); // 2. Input from memory StringReader in2 = new StringReader(s2); int c; while((c = in2.read()) != -1) System.out.print((char)c); // 3. Formatted memory input try { DataInputStream in3 = new DataInputStream( // Oops: must use deprecated class: new StringBufferInputStream(s2)); while(true) System.out.print((char)in3.readByte()); } catch(EOFException e) { System.out.println("End of stream"); } // 4. Line numbering & file output try { LineNumberReader li = new LineNumberReader( new StringReader(s2)); BufferedReader in4 = new BufferedReader(li); PrintWriter out1 = new PrintWriter( new BufferedWriter( new FileWriter("IODemo.out"))); while((s = in4.readLine()) != null ) out1.println( "Line " + li.getLineNumber() + s); out1.close(); } catch(EOFException e) { System.out.println("End of stream"); } // 5. Storing & recovering data try { DataOutputStream out2 = new DataOutputStream( new BufferedOutputStream( new FileOutputStream("Data.txt"))); out2.writeDouble(3.14159); out2.writeBytes("That was pi"); out2.close(); DataInputStream in5 = new DataInputStream( new BufferedInputStream( new FileInputStream("Data.txt"))); BufferedReader in5br = new BufferedReader( new InputStreamReader(in5)); // Must use DataInputStream for data: System.out.println(in5.readDouble()); // Can now use the "proper" readLine(): System.out.println(in5br.readLine()); } catch(EOFException e) { System.out.println("End of stream"); } // 6. Reading and writing random access // files is the same as before. // (not repeated here) } catch(FileNotFoundException e) { System.out.println( "File Not Found:" + args[1]); } catch(IOException e) { System.out.println("IO Exception"); } } } ///:~