Configuring Java Version in photo_manager

To ensure compatibility with older versions of AGP/flutter SDK, photo_manager supports configuring the project’s Java version through configuration files, environment variables, and other methods.

It looks for the Java version in the following order:

1. Configuration in gradle.properties using the java.version property. The value should be in the format of a Java version number, such as 1.8, 11, 17, 21, etc.
2. Using the JAVA_HOME environment variable, which should point to the installation path of the JDK. Typically, the Java executable is located at $JAVA_HOME/bin/java.
3. Configuration in gradle.properties using the java.home property.
4. Reading the runtime property java.home of the JDK.
5. If none of the above is found, it defaults to using JavaVersion.current().

Steps 4 and 5 should use the JDK configured in the Gradle settings, which is usually the same.

For example, if you configure java.version in gradle.properties as 17, it is equivalent to modifying the following properties in the build.gradle of photo_manager:

android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_17
        targetCompatibility JavaVersion.VERSION_17
    }
}