（1）写一个程序，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。（单词之间用空格隔开，如“Hello World My First Unit Test”）；
（2）编写单元测试进行测试；
（3）用ElcEmma查看代码覆盖率，要求覆盖达到100%
package com.czh;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Test1 {
public static void main(String[] args) throws Exception {
long time1 = System.currentTimeMillis();
BufferedReader reader = new BufferedReader(new FileReader(
"D:\wordtest.txt"));
StringBuffer buffer = new StringBuffer();
String line = null;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
reader.close();
Pattern expression = Pattern.compile("[a-zA-Z]+");
String string = buffer.toString();
Matcher matcher = expression.matcher(string);
Map<String, Integer> map = new TreeMap<String, Integer>();
String word = "";
int times = 0;
while (matcher.find()) {// 是否匹配单词
word = matcher.group();
if (map.containsKey(word)) {// 如果包含该键，单词出现过
times = map.get(word);
map.put(word, times + 1);
} else {
map.put(word, 1);// 否则单词第一次出现，添加到映射中
}
}
List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(
map.entrySet());
Comparator<Map.Entry<String, Integer>> comparator = new Comparator<Map.Entry<String, Integer>>() {
public int compare(Map.Entry<String, Integer> left,
Map.Entry<String, Integer> right) {
return (left.getValue()).compareTo(right.getValue());
}
};
Collections.sort(list, comparator);
int last = list.size() - 1;
try{
for (int i = last; i > last-10; i--) {
String key = list.get(i).getKey();
Integer value = list.get(i).getValue();
System.out.print("Top"+i+" : ");
System.out.println(key + " " + value);
}
}catch(Exception e){
//System.out.println("");
}
long time2 = System.currentTimeMillis();
System.out.print("耗时：");
System.out.println(time2 - time1+"ms");
}
}
二、
（1）把一个英语句子中的单词次序颠倒后输出。例如输入“how are you”，输出“you are how”；
（2）编写单元测试进行测试；
（3）用ElcEmma查看代码覆盖率，要求覆盖率达到100%。
package com.czh;
import java.util.Scanner;
public class Test2{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("请输入英文：");
String str = input.nextLine();
String[] strArr = str.split("\s+|[,]");
StringBuffer result = new StringBuffer();
for(int i = strArr.length -1;i >=0; i--){
result.append(strArr[i] + " ");
}
result.setCharAt(str.length()-0, (char) 0);
System.out.println("颠倒顺序后的结果为："+result.toString());
}
}