有人尝试过这个纯Java解决方案吗(没有SpringUtils):

//decimal to hex string 1=> 01, 10=>0A,..
String.format("%1$2s", Integer.toString(1,16) ).replace(" ","0");
//reply to original question, string with leading zeros. 
//first generates a 10 char long string with leading spaces, and then spaces are
//replaced by a zero string. 
String.format("%1$10s", "mystring" ).replace(" ","0");

不幸的是，这个解决方案只有在字符串中没有空格时才有效。

String input = "Apple";
StringBuffer buf = new StringBuffer(input);

while (buf.length() < 8) {
  buf.insert(0, '0');
}

String output = buf.toString();

你可能得处理edgecase。这是一个泛型方法。

public class Test {
    public static void main(String[] args){
        System.out.println(padCharacter("0",8,"hello"));
    }
    public static String padCharacter(String c, int num, String str){
        for(int i=0;i<=num-str.length()+1;i++){str = c+str;}
        return str;
    }
}

public class PaddingLeft {
    public static void main(String[] args) {
        String input = "Apple";
        String result = "00000000" + input;
        int length = result.length();
        result = result.substring(length - 8, length);
        System.out.println(result);
    }
}

使用Guava的Strings实用程序类:

Strings.padStart("Apple", 8, '0');

有人尝试过这个纯Java解决方案吗(没有SpringUtils):

//decimal to hex string 1=> 01, 10=>0A,..
String.format("%1$2s", Integer.toString(1,16) ).replace(" ","0");
//reply to original question, string with leading zeros. 
//first generates a 10 char long string with leading spaces, and then spaces are
//replaced by a zero string. 
String.format("%1$10s", "mystring" ).replace(" ","0");

不幸的是，这个解决方案只有在字符串中没有空格时才有效。