如果它是一个字符串，请使用StringBuilder或StringBuffer。下面的代码：

public class SplitNumber {

public static void main(String[] args){

int number = 12345678;

String numberStrBefore = Integer.toString(number);

StringBuffer numberStrAfter = new StringBuffer();

numberStrAfter.append(numberStrBefore.charAt(0));

numberStrAfter.append(numberStrBefore.charAt(1));

numberStrAfter.append('.');

numberStrAfter.append(numberStrBefore.charAt(2));

numberStrAfter.append(numberStrBefore.charAt(3));

numberStrAfter.append(numberStrBefore.charAt(4));

numberStrAfter.append('.');

numberStrAfter.append(numberStrBefore.charAt(5));

numberStrAfter.append(numberStrBefore.charAt(6));

numberStrAfter.append(numberStrBefore.charAt(7));

System.out.println("Number Before: " + numberStrBefore);

System.out.println("Number After: " + numberStrAfter.toString());

}

}

这里是一个方法同样的事情：

public class SplitNumber {

public static void main(String[] args){

int number = 12345678;

int[] split = {2,3,3}; //How to split the number

String numberStrAfter = insertDots(number, split);

System.out.println("Number Before: " + number);

System.out.println("Number After: " + numberStrAfter);

}

public static String insertDots(int number, int[] split){

StringBuffer numberStrAfter = new StringBuffer();

String numberStr = Integer.toString(number);

int currentIndex = 0;

for(int i = 0; i < split.length; i++){

for(int j = 0; j < split[i]; j++){

numberStrAfter.append(numberStr.charAt(currentIndex));

currentIndex++;

}

numberStrAfter.append('.');

}

numberStrAfter.deleteCharAt(numberStrAfter.length()-1); //Removing last "."

return numberStrAfter.toString();

}

}

这个版本，该方法，可以让你任意数量分割成任何你想要的格式，只需更改将“split”变量转换为您想要将字符串拆分为的格式。 (例如：将12345678拆分为：1.1234.5.67.8意味着“拆分”必须设置为{1,4,1,2,1})。