package dkc_Parrtern1;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/*
     正則表示式的獲取
         配合IO流，從一個文字讀取檔案，獲取檔案裡面單詞的個數
 */
public class RegexDemo7 {
    public static void main(String[] args) {
        
 
//在E盤的word.txt中隨便寫入幾行漢字加單詞
        /*大家好！hello everybody，我來自寒寨，
        My name is duxiansen,I come from HanZhai.哈哈*/
        File file = new File("E:\\word.txt");
        //1.讀取檔案宣告BufferedReader物件br
        BufferedReader br = null;
        //2.建立Pattern的物件,傳入一個正則表示式
        Pattern p = null;
        //3.呼叫p物件中的matcher 獲取匹配器物件
 

        Matcher matcher = null;
        //4.定義計算器
        int count = 0;
        try {
            br = new BufferedReader(new FileReader(file));
            String str ="";
            while((str = br.readLine()) != null) {
                p = Pattern.compile("\\b[a-zA-Z]+\\b");
                matcher 
 
= p.matcher(str);
                while(matcher.find()) {
                    count++;
                }
            }
            System.out.println(count);
            br.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }
}

package dkc_Parrtern1;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/*
     正則表示式的獲取功能:
     Pattern和Matcher類的使用
         jin tian yao xia yu,da jia pa bu pa?huang bu huang? are you sure?
         獲取由三個字元組成的單詞
 */
public class RegexDemo6 {
    public static void main(String[] args) {
        String str = "jin tian yao xia yu,da jia pa bu pa?huang bu huang? are you sure?";
        //1.建立Pattern的物件,傳入一個正則表示式
        Pattern p = Pattern.compile("\\b[a-zA-Z]{3}\\b");//(\\b單詞的邊界)
        
        //呼叫p物件中的matcher 獲取匹配器物件
        Matcher matcher = p.matcher(str);
        
        //遍歷得結果
        int count = 0;
        while(matcher.find()) {
            System.out.print(matcher.group()+" ");
            count++;
        }
        System.out.println(count);
        // 不能單獨使用，必須和found方法配合使用，否則報錯:No match found 
        //System.out.println(matcher.group());
    }
}