analay.java

编译原理词法分析程序,对pascal语言进行词法分析并生成相应的类号.

import java.io.*;

class Program {
	public static void main(String[] args) throws IOException {
		InputStreamReader isr = new InputStreamReader(System.in);
		BufferedReader br = new BufferedReader(isr);
		String str = br.readLine();
		Analay analay = new Analay(21);
		System.out.println("该标识符的类号：" + analay.exchange(str));
		// System.in.read();
	}
}

public class Analay {

	public Analay(int n) {

		this.n = n;
		keywords = new String[n];
		try {
			FileReader fr = new FileReader("words.txt");
			BufferedReader br = new BufferedReader(fr);
			String str;
			int i = 0;

			while ((str = br.readLine()) != null) {
				keywords[i++] = new String(str);
			}

			br.close();
			fr.close();
		} catch (IOException e) {
			System.out.println("文件处理出错");
		}

	}

	public String exchange(String str) {
		for (int i = 0; i < n; i++) {
			if (keywords[i].equals(str)) {
				return Integer.toString(i);
			}
		}
		return Integer.toString(21);
	}

	private String[] keywords;

	private int n;

}