//: c10:IOStreamDemo.java // From Thinking in Java, 2nd Edition // Available at http://www.BruceEckel.com // (c) Bruce Eckel 1999 // Copyright notice in Copyright.txt // Typical IO Stream Configurations import java.io.*; import com.bruceeckel.tools.*; public class IOStreamDemo { public static void main(String[] args) { try { // 1. Buffered input file DataInputStream in = new DataInputStream( new BufferedInputStream( new FileInputStream(args[0]))); String s, s2 = new String(); while((s = in.readLine())!= null) s2 += s + "\n"; in.close(); // 2. Input from memory StringBufferInputStream in2 = new StringBufferInputStream(s2); int c; while((c = in2.read()) != -1) System.out.print((char)c); // 3. Formatted memory input try { DataInputStream in3 = new DataInputStream( new StringBufferInputStream(s2)); while(true) System.out.print((char)in3.readByte()); } catch(EOFException e) { System.out.println( "End of stream encountered"); } // 4. Line numbering & file output try { LineNumberInputStream li = new LineNumberInputStream( new StringBufferInputStream(s2)); DataInputStream in4 = new DataInputStream(li); PrintStream out1 = new PrintStream( new BufferedOutputStream( new FileOutputStream( "IODemo.out"))); while((s = in4.readLine()) != null ) out1.println( "Line " + li.getLineNumber() + s); out1.close(); // finalize() not reliable! } catch(EOFException e) { System.out.println( "End of stream encountered"); } // 5. Storing & recovering data try { DataOutputStream out2 = new DataOutputStream( new BufferedOutputStream( new FileOutputStream("Data.txt"))); out2.writeBytes( "Here's the value of pi: \n"); out2.writeDouble(3.14159); out2.close(); DataInputStream in5 = new DataInputStream( new BufferedInputStream( new FileInputStream("Data.txt"))); System.out.println(in5.readLine()); System.out.println(in5.readDouble()); } catch(EOFException e) { System.out.println( "End of stream encountered"); } // 6. Reading/writing random access files RandomAccessFile rf = new RandomAccessFile("rtest.dat", "rw"); for(int i = 0; i < 10; i++) rf.writeDouble(i*1.414); rf.close(); rf = new RandomAccessFile("rtest.dat", "rw"); rf.seek(5*8); rf.writeDouble(47.0001); rf.close(); rf = new RandomAccessFile("rtest.dat", "r"); for(int i = 0; i < 10; i++) System.out.println( "Value " + i + ": " + rf.readDouble()); rf.close(); // 7. File input shorthand InFile in6 = new InFile(args[0]); String s3 = new String(); System.out.println( "First line in file: " + in6.readLine()); in6.close(); // 8. Formatted file output shorthand PrintFile out3 = new PrintFile("Data2.txt"); out3.print("Test of PrintFile"); out3.close(); // 9. Data file output shorthand OutFile out4 = new OutFile("Data3.txt"); out4.writeBytes("Test of outDataFile\n\r"); out4.writeChars("Test of outDataFile\n\r"); out4.close(); } catch(FileNotFoundException e) { System.out.println( "File Not Found:" + args[0]); } catch(IOException e) { System.out.println("IO Exception"); } } } ///:~