Use regular to replace the src of the img tag

Requirement: Due to system switching, it is required to patch the src attribute of the img tag in the webpage content in the database. For example:

Content="<p><img title=\"122444234\" src=\"/files/post/122444234.jpg\"/><p>Other characters";

After the replacement is required:

Content="<p><img title=\"122444234\" src=\"http://xxx.xxx.com/files/post/122444234_500.jpg\" /><p>Other characters";

Use regular to solve, the code is as follows (ApiUtil.java static method)

Java code collection code

    /**
     * Double-pack the src in the img tag
     * @param content content
     * @param replaceHttp needs to be added to the domain name in src
     * @param size needs to add _size to the file name in src
     * @return
     */
    Public static String repairContent(String content,String replaceHttp,int size){
        String patternStr="<img\\s*([^>]*)\\s*src=\\\"(.*?)\\\"\\s*([^>]*)>";
        Pattern pattern = Pattern.compile(patternStr,Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(content);
        String result = content;
        While(matcher.find()) {
            String src = matcher.group(2);
            Logger.debug("pattern string:"+src);
            String replaceSrc = "";
            If(src.lastIndexOf(".")>0){
                replaceSrc = src.substring(0,src.lastIndexOf("."))+"_"+size+src.substring(src.lastIndexOf("."));
            }
            If(!src.startsWith("http://")&&!src.startsWith("https://")){
                replaceSrc = replaceHttp + replaceSrc;
            }
            Result = result.replaceAll(src,replaceSrc);
        }
        Logger.debug(" content == " +content);
        Logger.debug(" result == " + result);
        Return result;
    }

 Test code:

Java code collection code

Public static void main(String[] args) {
        String content = "<p><img title=\"10010001\" src=\"/files/post/10010001.gif\" width=\"200\" height=\"300\" />" +
                "</p><p><img title=\"10010002\" src=\"/files/post/10010002.gif\" width=\"500\" height=\"300\" /><p>  </p>"+
                "</p><p><img title=\"10010003\" src=\"/files/post/10010003.gif\" width=\"600\" height=\"300\" /><p>  </p>";
        String replaceHttp = "http://www.baidu.com";
        Int size = 500;
        String result = ApiUtil.repairContent(content, replaceHttp, size);
        System.out.println(result);
    }

The key is the regular expression:

<img\\s*([^>]*)\\s*src=\\\"(.*?)\\\"\\s*([^>]*)>

In particular ([^>]) can’t be replaced with ., otherwise it will only match <img to the last “>” symbol of the string. If the content of each src is different, only the last src will be replaced.