正則驗證字符串中是否存在數字

//正則匹配表達式
String regExOne = "^[1-9]{1}$";
String regExTow = "^[0-9]{2}$";
Pattern patternOne = Pattern.compile(regExOne);
Pattern patternTow = Pattern.compile(regExTow);

List<String> nameList = new ArrayList<>();
nameList.add("7號樁");
nameList.add("9號樁");
nameList.add("1號樁");
nameList.add("3號樁");
nameList.add("11號樁");
nameList.add("11號樁");
nameList.add("8號樁");
nameList.add("2號樁");
nameList.add("4號樁");
nameList.add("6號樁");

//建立map設置每一個元素的位置對於的值
Map<String,Integer> map = new HashMap<>();
//截取後的數據數字數組
int[] arrs = new int[nameList.size()];
for(int i=0,size = nameList.size();i<size;i++){
    String name = nameList.get(i);
    //取出第第一位，驗證是不是數字
    String nameIndexOne = name.substring(0,1);
    //驗證是否存在名稱中是否存在數字
    Matcher matcherIndexOne = patternOne.matcher(nameIndexOne);
    boolean indexOne =  matcherIndexOne.find();
    if(indexOne){
        //取出第第二位，驗證是不是數字
        String nameIndexTow = name.substring(0,2);
        Matcher matcherIndexTow = patternTow.matcher(nameIndexTow);
        boolean indexTow = matcherIndexTow.find();
        if(indexTow){
            map.put(nameIndexTow,i);
            arrs[i] = Integer.parseInt(nameIndexTow);
        }else{
            map.put(nameIndexOne,i);
            arrs[i] = Integer.parseInt(nameIndexOne);
        }
    }
}
Arrays.sort(arrs);
for(int j=0,size=arrs.length;j<size;j++){
   System.out.print(arrs[i]);
}

// 判斷一個字符串是否含有數字
    public boolean HasDigit(String content) {
        boolean flag = false;
        Pattern p = Pattern.compile(".*\\d+.*");
        Matcher m = p.matcher(content);
        if (m.matches()) {
            flag = true;
        }
        return flag;
    }

//判斷一個字符是否都爲數字 
    public static boolean isDigit(String strNum){
        return strNum.matches("[0-9]{1,}");
    }
    
    // 判斷一個字符串是否都爲數字  
    public static boolean isDigit2(String strNum) {  
        Pattern pattern = Pattern.compile("[0-9]{1,}");  
        Matcher matcher = pattern.matcher((CharSequence) strNum);  
        return matcher.matches();  
    }

 

//截取數字  【讀取字符串中第一個連續的字符串，不包含後面不連續的數字】
    public static String getNumbers(String content) {  
        Pattern pattern = Pattern.compile("\\d+");  
        Matcher matcher = pattern.matcher(content);  
        while (matcher.find()) {  
           return matcher.group(0);  
        }  
        return "";  
    }  
      
    // 截取非數字  
    public static String splitNotNumber(String content) {  
        Pattern pattern = Pattern.compile("\\D+");  
        Matcher matcher = pattern.matcher(content);  
        while (matcher.find()) {  
            return matcher.group(0);  
        }  
        return "";  
    }

 

用java自帶函數
//判斷一個字符串是否爲數字
    public static boolean isNumeric(String str){
        for (int i =  str.length(); --i>=0;) {
            if(!Character.isDigit(str.charAt(i))){
                return false;
            }
        }
        return true;
    }

//判斷一個字符串是否爲數字 用ASCII碼
    public static boolean isNumeric3(String str){
        for(int i=str.length(); --i>=0;){
            char c=str.charAt(i);
            if (c < 48 || c > 57)
                return false;
        }
        return true;
    }

//正則 
public static boolean isNumeric2(String str){
        Pattern pattern=Pattern.compile("[0-9]*");
        return pattern.matcher(str).matches();
    }