How do I add package level annotations or edit package-info.java?
In eclipse
Since package-info.java isn't a valid identifier for a class it cannot be created as a class in Eclipse.
I found that when you create a new package there is a check box to check if you want a package-info.java.
To create a package-info.java file in an existing package:
- Right-click on the package where you want a package-info.java.
- Select New->Package.
- Check the Create package-info.java check box.
- Click on Finish.
Open explorer, go to src/your package folder.
right click -> Create new textfile: name it package-info.java.
Go back to eclipse and edit and add the desired content.
package-info.java
The package-info.java
is a Java file that can be added to any Java source package. Its purpose is to provide a home for package level documentation and package level annotations.
Simply create the package-info.java
file. Add the package declaration in the file. In fact, the only thing the package-info.java file must contain is the package declaration.
Example of a minimal package info file:
package com.example.myapp.backend.data;
Example of a package-level annotation, @ParametersAreNonnullByDefault
:
@ParametersAreNonnullByDefault
package com.example.myapp.backend.data;
import javax.annotation.ParametersAreNonnullByDefault;
For more info, see the Java specifications, in The Java® Language Specification, section 7.4.1 Named Packages.
Summary from the article here
In package-info.java:
@PackageLevelAnnotation
package blammy; // package with a package level annotation.
import blammy.annotation.PackageLevelAnnotation;
In PackageLevelAnnotation.java
package blammy.annotation;
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.PACKAGE)
public @interface PackageLevelAnnotation
{
// stuff as required.
}
Edit: more package level info. Here is a link to the package chapter in the Java Language Spec: packages