获取定长字符串

public class FixedlengthStr {
    
    public static String getFixedLengthStr(String str,int size){
        if(size == 0){
            size = 10;
        }
        StringBuffer sb = new StringBuffer();
        if(str.length() == size){
            return str;
        }else if (str.length() < size) {
            for(int i = 0; i < size - str.length();i++){
                sb.append("0");
            }
            sb.append(str);
            return sb.toString();
        }else {
            return str.substring(0, size);
        }
    }
    
    public static String getFixedLengthStr(String str){
        return getFixedLengthStr(str, 10);
    }
    
    public static void main(String[] args) {
        String aa = "0123456789";
        String bb = "01234567";
        String cc = "01234567891010";
        
        System.out.println(aa + " | " + FixedlengthStr.getFixedLengthStr(aa));
        System.out.println(bb + " | " + FixedlengthStr.getFixedLengthStr(bb));
        System.out.println(cc + " | " + FixedlengthStr.getFixedLengthStr(cc));
        
    }
    
}

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