newiodemo.java

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//:NewIODemo.java
// Java 1.1 ID 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. Formattted memory input
			try {
				DataInputStream in3 = 
					new DataInputStream (
					//Oops: must use deprecated class:
						new StringBufferInputStream(s2));
				while(true)
					System.out.println((char)in3.readByte());					
			} 
			catch(EOFException e) {
				System.out.println("End of stream");
			}
			
			// 4.Line numvering & file output
			try {
				LineNumberReader li =
					new LineNumberReader( 
						new StringReader(s2) );
				BufferedReader in4 = 
					new BufferedReader(li);
				PrintWriter out1 = 
					new PrintWriter(
						new BufferedWriter(
							new FileWriter("IDDemo.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 dta;
				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");
		}
	}
}////:~