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Q&A Prevent anonymously subclassing

There is no keyword or compile-time construct to prevent this, but it can be accomplished through the use of a runtime exception: class Parent { public Parent() { if (getClass(...

posted 5mo ago by Andreas witnessed the end of the world today‭ · edited 5mo ago by Andreas witnessed the end of the world today‭

Answer

#4: Post edited by

Andreas witnessed the end of the world today‭ · 2024-07-27T06:23:45Z (5 months ago)

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There is no keyword or compile-time construct to prevent this, but it can be accomplished through the use of a runtime exception:
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
~~```~~

There is no keyword or compile-time construct to prevent this, but it can be accomplished through the use of a runtime exception:
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
```
For actual use in production code, one should probably reconsider the reasons for which one would like to do this. Limiting the creation of anonymous classes is a possibility, but generally a bad idea.

#3: Post edited by

Andreas witnessed the end of the world today‭ · 2024-07-26T16:32:02Z (5 months ago)

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~~There is no compile-time construct or keyword to prevent this, but you can accomplish it through the use of a runtime exception:~~
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
```

There is no keyword or compile-time construct to prevent this, but it can be accomplished through the use of a runtime exception:
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
```

#2: Post edited by

Andreas witnessed the end of the world today‭ · 2024-07-26T14:08:23Z (5 months ago)

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~~There is no compile-time construct or keywords to prevent this, but you can accomplish it through the use of a runtime exception:~~
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
```

There is no compile-time construct or keyword to prevent this, but you can accomplish it through the use of a runtime exception:
```
class Parent {
public Parent() {
if (getClass().isAnonymousClass()) {
throw new IllegalStateException("You violated my secret rule!");
}
}
}
```

#1: Initial revision by

Andreas witnessed the end of the world today‭ · 2024-07-26T14:08:07Z (5 months ago)

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There is no compile-time construct or keywords to prevent this, but you can accomplish it through the use of a runtime exception:

```
class Parent {
    
    public Parent() {
        if (getClass().isAnonymousClass()) {
            throw new IllegalStateException("You violated my secret rule!");
        }
    }
}
```

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