Difference beetwen = and == in regex java

I couldn’t define a regular expression between "=" and "==". To explain more clear, look at the codes.

if(Pattern.matches("(.*)=(.*)", text))
{
        
    // code block 1
}

if(Pattern.matches("(.*)==(.*)", text))
{

    // code block 2
}

Sample text1 : asdasdasd=asdasdasd

Sample text2 : asdasdasd==asdasdasd

When the text be like above samples, in any case only code block 1 is working.
Also I know "( .* )=( .* )" this expression is wrong. I tried "(.*)=(^=)" etc. but I couldn’t figure out. I want to find solution which if text has a "=", code block 1 works, if text has "==", code block 2 works.

>Solution :

To exclude a character, that isn’t (^=), but between square brackets [^=], giving either :

• (.*[^=])=([^=].*)
• (.*)(?<!=)=(?!=)(.*) with negatives lookahead+lookbehind

Or could work with String.contains, in the right order

if (text.contains("==")) {
    System.out.println("Case 2");
} else if (text.contains("=")) {
    System.out.println("Case 1");
}