一个字符串中出现次数最多的单词 java语言实现

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

public class SubStringAppear
{
public static void main(String args[])
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String str=null;
try {
str = br.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int a=0,b=0;
ArrayList list=new ArrayList();
int i,j;
while(true)
{
for(i=b;i<str.length();i++)
{
if(str.charAt(i)!=' ')
{
a=i;
break;
}
}
for(j=a;j<str.length();j++)
{
if(str.charAt(j)==' ')
{
b=j;
break;
}
}
if(i<str.length()&&j<str.length())
{
list.add(str.substring(a, b));
}
if(i<str.length()&&j==str.length())
{
list.add(str.substring(a,str.length()));
break;
}
if(i==str.length())
{
break;
}
}
Iterator<String> ite=list.iterator();
while(ite.hasNext())
{
System.out.println(ite.next());
}
HashMap<String,Integer> map=new HashMap<String,Integer>();
ite=list.iterator();
while(ite.hasNext())
{
String s=ite.next();
if(map.get(s)==null)
{
map.put(s, 1);
}
else
{
map.put(s, new Integer(map.get(s)+1));
}
}
Collection col=map.values();
Iterator<Integer> io=col.iterator();
int max=0;
while(io.hasNext())
{
int k=io.next();
if(max<k)
{
max=k;
}
}
Set<Map.Entry<String, Integer>> set=map.entrySet();
Iterator<Map.Entry<String, Integer>> it=set.iterator();
while(it.hasNext())
{
Map.Entry<String , Integer> entry=it.next();
if(entry.getValue()==max)
{
System.out.println("出现次数最多的单词为: "+entry.getValue()+"出现的次数为： "+max);
}
}

}
}
//用java的迭代器和HashMap实现的