第2次作业的简单版代码

import java.util.;import java.util.Map.;import java.io.;
import java.util.regex.;
public class WordCount
{
@SuppressWarnings({ "deprecation", "unchecked" })
public static void main(String[]S)throws Exception
{
if(S.length!=1)System.out.println("请输入命令行参数,即要读的文件");
else
{
FileInputStream f=new FileInputStream(S[0]);
DataInputStream in=new DataInputStream(f);
HashMap<String,Integer>hm
=new HashMap<String,Integer>();
String s;int n=0,w=0;for(;(s=in.readLine())!=null;)
{
//统计包含非空白字符的行数n
if(!s.matches("\s"))
{
n++;
//匹配单词
Matcher m=Pattern.compile
("[^a-zA-Z0-9]([a-zA-Z]{4}[a-zA-Z0-9]*)").matcher(s);
for(;m.find();w++)
{
s=m.group(1).toLowerCase();
if(hm.containsKey(s))hm.put(s,hm.get(s)+1);
else hm.put(s,1);
}
}
}
ArrayList<Entry<String,Integer>>l
=new ArrayList<Entry<String,Integer>>(hm.entrySet());
Comparator<Entry<String, Integer>> c=new Comparator<Entry<String,Integer>>()
{
public int compare(Entry<String,Integer>i
,Entry<String,Integer>j)
{
int k=j.getValue().compareTo(i.getValue());
if(k==0)return -j.getKey().compareTo(i.getKey());
return k;
}
};
Collections.sort(l,c);
PrintWriter o=new PrintWriter("result.txt");
o.println("characters: "+f.getChannel().size()
+"\nwords: "+w+"\nlines: "+n);
int i;for(i=0;i<Math.min(10,l.size());i++)
o.println(l.get(i).getKey()+": "+l.get(i).getValue());
o.close();
}
}
}