在Java中更改字符串中的整数

Question

I need to change the string by decreasing the number by one eg 011 then 010 etc. if 009 then 008.

However, I cannot think of the ways to do this thing please help me:

<img width="188" height="307" src="File1.files/image006.png" alt="NNMF_Input.png" v:shapes="image_x0020_33" />
<img width="506" height="200" src="File1.files/image014.png" v:shapes="image_x0020_1" />
<img width="506" height="411" src="File1.files/image016.png" v:shapes="image_x0020_2" />
<img width="515" height="179" src="File1.files/image018.png" v:shapes="image_x0020_3" />

Here, I want to change files/image006.png to files/image005.png and change say files/image010.png to files/image009.png .

PS They are all in strings! not HTML tags in fact

Answer 1

try regex

    Matcher m = Pattern.compile("(?<=/image)\\d{3}").matcher(str);
    StringBuffer sb = new StringBuffer();
    while(m.find()) {
        m.appendReplacement(sb, String.format("%03d", Integer.parseInt(m.group()) - 1));
    }
    m.appendTail(sb);

Answer 2

int i = Integer.parseInt("011");
System.out.format("%03d", i-1);

Answer 3

Just for funny - scala solution :)

scala> def increment(str:String) = str.split("[^0-9]").
filter( s => s.nonEmpty && s.length >1).
foldLeft(str)((acc,curr) => acc.replace(curr, {val res = (curr.toInt+1).toString;Range(0,curr.length - res.length).
foldLeft(res)((acc,curr)=> "0"+acc) }))
increment: (str: String)String

scala> increment("File1.files/image014.png")
res10: String = File1.files/image015.png

Answer 4

String str = "000110";

// Get the last index and add 1 to determine number of leading zeros
int i = str.lastIndexOf('0') + 1;

// Subtract or do any math on the number you want
int newNumber = Integer.parseInt(str) - 1;

// Format the new string with leading zeros
String newString = String.format("%0" + i + "d", newNumber);

// See the new string
System.out.println(newString);

EDIT

To answer your edited question:

String str = "image0110";

// Get the number (above example 0110) from original string using the last character 'e 'from 'image'
str = str.substring(str.lastIndexOf('e') + 1);

// Get how many leading zeros are in there
int i = str.lastIndexOf('0') + 1;

// Do the math
int newNumber = Integer.parseInt(str) - 1;

// Form the new string starting with 'image' and leading zeros
String newString = "image" + String.format("%0" + i + "d", newNumber);

System.out.println(newString);