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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"); } }} ///:~
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