Add Check Support for Java 17 Sealed Classes: MissingOverride

[mahfouz72]

child of #14969

check documentation : https://checkstyle.org/checks/annotation/missingoverride.html

---

PS D:\CS\test> cat config.xml                                                   
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
<module name="Checker">
    <property name="charset" value="UTF-8"/>
    <module name="TreeWalker">
            <module name="MissingOverride"/>
    </module>
</module>
PS D:\CS\test> cat src/Test.java                                                
class A {
    void a() {
        synchronized (this) {}
    }
}
public sealed class Test extends A permits Testt  {
    void test(Object obj) {
        synchronized (this) {}
    }

    /**
     * {@inheritDoc}
     */
    void a() {}  // violation
}

final class Testt extends Test {

    /**
     * {@inheritDoc}
     */
    void test(Object obj) {   // violation
    }
}
PS D:\CS\test> java  -jar checkstyle-10.17.0-all.jar -c config.xml src/Test.java
Starting audit...
[ERROR] D:\CS\test\src\Test.java:14:5: Must include @java.lang.Override annotation when '@inheritDoc' Javadoc tag exists. [MissingOverride]
[ERROR] D:\CS\test\src\Test.java:22:5: Must include @java.lang.Override annotation when '@inheritDoc' Javadoc tag exists. [MissingOverride]
Audit done.
Checkstyle ends with 2 errors.
PS D:\CS\test> 

---

We are ok here. no update is required.

[rnveach]

synchronized (this) {} // violation

I think this is wrong.

I don't see an issue with the check, but the example should also have a violation inside a sealed class also to cover our bases.

@mahfouz72 please update examples.

[mahfouz72]

First post is updated

[rnveach]

I am good.

[nrmancuso]

We don't need to take any further action here.