findchar.java

nanjing university cs 的java课件。 对新手很有用。付课件中源码。

import java.io.*;

public class Findchar {
	public static void main(String[] args) throws Exception {
		if (args.length != 2) {
			 throw new Exception("need char / file");
		}
		int match = args[0].charAt(0);
		FileInputStream
			fileIn = new FileInputStream(args[1]);
		LineNumberInputStream
			in = new LineNumberInputStream(fileIn);
		int ch;
		while ( (ch = in.read()) != -1) {
			if (ch == match) {
				System.out.println
					("‘" + (char) ch + "’at line" +in.getLineNumber());
				System.exit(0);
			}
		}
		System.out.println(ch + "not found");
		System.exit(1);
	}
}