importClass(android.database.ContentObserver)
new JavaAdapter(ContentObserver, {onChange: (a)=>{
    log("aa".concat(a))
}})

13:36:40.017/E: Wrapped java.lang.NoSuchMethodException: adapter1.<init> [interface org.mozilla.javascript.Scriptable, class org.mozilla.javascript.ContextFactory] ([remote]main.js#2)
Wrapped java.lang.NoSuchMethodException: adapter1.<init> [interface org.mozilla.javascript.Scriptable, class org.mozilla.javascript.ContextFactory]
    at [remote]main.js:2:0

new JavaAdapter(
    ContentObserver,
    {
        onChange: () => {
            log('aa');
        }
    },
    new android.os.Handler()
);

大概是这样吧