软件测试第二次作业 - 写一个Java程序，用于分析一个字符串中各个单词出现的频率，并将单词和它出现的频率输出显示。

 1 import java.util.HashMap;
 2 import java.util.Iterator;
 3 import java.util.Map;
 4 import java.util.Set;
 5 
 6 public class Demo {
 7 
 8     public void countWord(String str) {
 9         String[] wordsArray = str.split(" ");
10         Map<String, Integer> wordsMap = new HashMap<String, Integer>();
11         for (String word : wordsArray) {
12 
13             if (wordsMap.containsKey(word)) {
14                 wordsMap.put(word, wordsMap.get(word) + 1);
15             } else {
16                 wordsMap.put(word, 1);
17             }
18         }
19 
20         Set<String> setKey = wordsMap.keySet();
21         Iterator<String> itKey = setKey.iterator();
22         while (itKey.hasNext()) {
23             String word = itKey.next().toString();
24             int count = wordsMap.get(word);
25 
26             System.out.println("单词    " + word + "  出现" + count + "次");
27 
28         }
29     }
30 
31 }

 1 import static org.junit.Assert.*;
 2 import org.junit.Test;
 3 
 4 public class DemoTest {
 5 
 6     @Test
 7     public void testCountWord() {
 8         Demo demo = new Demo();
 9         demo.countWord("Hello World Hello Java Hello Test");
10     }
11 
12 }