ex26.java

JAVA编程思想第四版英文原版习题答案. pdf原版的

// holding/Ex26.java
// TIJ4 Chapter Holding, Exercise 26, page 423
/* Take the resulting Map from the previous exercise and re-create the 
* order of the words as they appeared in the original file.
*/
import java.util.*;
import net.mindview.util.*;

public class Ex26 {
	public static void main(String[] args) {
		Map<String,ArrayList<Integer>> m = 
			new LinkedHashMap<String,ArrayList<Integer>>();
		List<String> words = new LinkedList<String>();
		words.addAll(new TextFile("SetOperations.java", "\\W+"));
		System.out.println("Words in file: " + words);
		Iterator itWords = words.iterator();
		int count = 0;
		while(itWords.hasNext()) {
			String s = (String)itWords.next();
			count++;			
			if(!m.keySet().contains(s)) {	
				ArrayList<Integer> ai = 
					new ArrayList<Integer>();		
				ai.add(0, count);
				m.put(s, ai);
			}
			else {
				m.get(s).add(count);
				m.put(s, m.get(s));  	
			}
		}
		System.out.println();
		System.out.println("Map of word locations: " + m);
		// New Map to hold sorted words, keyed by location:
		Map<Integer,String> replay = new TreeMap<Integer,String>();
		Iterator<Map.Entry<String,ArrayList<Integer>>> it = 
			m.entrySet().iterator();
		while(it.hasNext()) {
			Map.Entry<String,ArrayList<Integer>> me = it.next();
			for(int i = 0; i < me.getValue().size(); i++)
				replay.put(me.getValue().get(i),
					me.getKey());
		}
		System.out.println();
		System.out.println("TreeMap of ordered locations, words: " + replay);
		System.out.println();
		// Display words in order as TreeMap values():
		System.out.println("Words in original order: " +
			replay.values());
	}	
}