I want to know how to replace the string in Java.
E.g.
String a = "adf?sdf";
How can I replace and avoid special characters?
You can get rid of all characters outside the printable ASCII range using String#replaceAll() by replacing the pattern [^\x20-\x7e] with an empty string:
String#replaceAll()
[^\x20-\x7e]
a = a.replaceAll("[^\x20-\x7e]", "");
But this actually doesn't solve your actual problem. It's more a workaround. With the given information it's hard to nail down the root cause of this problem, but reading either of those articles must help a lot:
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