parsestring.java

JAVA 2入门经典 练习答案

// Chapter 8 Exercise 2

import java.io.StreamTokenizer;
import java.io.BufferedReader;
import java.io.StringReader;
import java.io.IOException;
import java.util.Vector;

public class ParseString {
  public static void main(String[] args) {
    String str = "Fred, Bill, Jane, Joan, Janet,John";
    char separator = ',';
    StreamTokenizer tokenizer = new StreamTokenizer(new BufferedReader(new StringReader(str)));
    tokenizer.resetSyntax();              
    tokenizer.wordChars('\u0000',(char)(separator-1));    // Everything is a word character
    tokenizer.wordChars((char)(separator+1),'\u00ff');    // except for the separator
    tokenizer.whitespaceChars(separator,separator);       // Whitespace separates words so just the separator
  
    int type = 0;                                         // Stores the value returned by nextToken()
    Vector tokens = new Vector();                         // Will store the tokens that we find
    try {
      while((type = tokenizer.nextToken()) != StreamTokenizer.TT_EOF) {   // As long as we don't have EOF
        if(type == StreamTokenizer.TT_WORD)                               // Check for a word
          tokens.add(tokenizer.sval);                                     // and save it in the vector
        else
          assert false;                                                   // We only expect words
      }
    }
    catch(IOException e) {
      e.printStackTrace();
      System.exit(1);
    }

  System.out.println("The tokens in the string are:"); 
    for( int i = 0 ; i< tokens.size() ; i++)
      System.out.print("  "+(String)tokens.elementAt(i));
  }
}