求助一道题目 - 黑马程序员技术交流社区

import java.util.*;
import java.io.*;
import java.lang.*;
import java.awt.Frame;
import java.awt.TextArea;
class CountPara extends Frame
{
CountPara(RandomAccessFile randomR)
{
Map<String,Integer> map = new HashMap<String, Integer>();
map = countWords(map,randomR);
countOnce(map);
countFreq(map);
}
public Map countWords(Map<String,Integer> map, RandomAccessFile raf)
{
byte[] b = new byte[1];
char[] temp = new char[1];
StringBuffer sb = new StringBuffer();
String s;
char c;
try
{
while(raf.getFilePointer()<raf.length())
{
raf.readFully(b);
s = new String(b);
temp = s.toCharArray();
c = temp[0];
//从非空格字符开始数算
while(Character.isLetter(c))
{
sb.append(new String(temp));
raf.readFully(b);
s = new String(b);
temp = s.toCharArray();
c = temp[0];
}
if(map.containsKey(sb.toString()))
{
map.put(sb.toString(), 1+map.get(sb.toString()));
}
else if(sb.length()> 0)
map.put(sb.toString(), 1);
sb.delete(0,sb.length());
}
raf.close();
}
catch (EOFException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
System.out.println("全文共出现"+ map.size() +" 个单词。");
return map;
}
public void countOnce(Map<String, Integer> map)
{
Set<String> keySet = map.keySet();
Iterator<String> it = keySet.iterator();
System.out.print("出现一次的单词有： ");
int i = 1;
while(it.hasNext())
{
String s = it.next();
if(map.get(s)==1)
{
System.out.print(i+"."+s+" ");
i++;
}
}
}
public void countFreq(Map<String,Integer> map)
{
//将map.entry转换成arraylist
List<Map.Entry<String,Integer>> list = new ArrayList<
Map.Entry<String,Integer>>(map.entrySet());
Collections.sort(list,new Comparator<Map.Entry<String,Integer>>()
{
public int compare(Map.Entry<String,Integer> o1, Map.Entry<String,Integer> o2)
{
return o1.getValue().compareTo(o2.getValue());
}
});
Frame f = new Frame();
TextArea text = new TextArea();
f.setSize(400,300);
f.setLocation(300,200);
text.setRows(50);
text.setColumns(5);
f.add(text);
f.setVisible(true);
for(Map.Entry<String,Integer> mapping:list)
text.append(mapping.getKey()+":"+mapping.getValue()+" ");
}
}
public class Three
{
public static void main (String[] args)
{
System.out.println("hallelujah!");
System.out.println();
RandomAccessFile raf = null;
try
{
raf = new RandomAccessFile("hello.txt","r");
CountPara ctp = new CountPara(raf);
raf.close();
}
catch(EOFException e)
{
e.printStackTrace();
}
catch(IOException e)
{
e.printStackTrace();
}
}
}

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// 创建随机文件流,读取文件,返回读到的数据
public static String readFile() throws Exception {
RandomAccessFile raf = new RandomAccessFile("d:/hello.txt", "rw");
// 创建一个容器来存储读到的数据
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = raf.readLine()) != null) {
sb.append(line);
sb.append(" ");
}
raf.close();
return sb.toString();
}
// 将传入的数据进行判断
private static Map<String, Integer> splitLine(String line) {
String regex = "\\b[A-Za-z]+\\b";
Pattern p = Pattern.compile(regex);
Matcher matcher = p.matcher(line);
// 创建map集合将单词传入
Map<String, Integer> map = new TreeMap<String, Integer>();
while (matcher.find()) {
String key = matcher.group();
if (map.containsKey(key)) {
int num = map.get(key);
map.put(key, num + 1);
} else {
map.put(key, 1);
}
}
ta.append("共出现的单词个数有:" + map.size() + "\r\n");
// 获取Set集合
Set<Map.Entry<String, Integer>> set = map.entrySet();
Iterator<Map.Entry<String, Integer>> it = set.iterator();
while (it.hasNext()) {
Entry<String, Integer> str = it.next();
if (str.getValue() == 1) {
ta.append("单词:" + str.getKey() + ":只出现了一次\r\n");
}
}
return map;
}

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