Android开发中使用rhino-android引擎，JS如何导入Java包？

• 迁移背景：将PC端Java项目迁移至Android，JS文件存放路径为app/src/main/assets/scripts，Java文件路径为app/src/main/java，使用rhino-android作为脚本引擎。
• 当前状态：Java调用JS函数正常，但JS中导入Java包时触发错误。
• 出错代码示例：

const LifeFactory = importPackage('server.life.LifeFactory');

• 报错信息：

javax.script.ScriptException: org.mozilla.javascript.EvaluatorException: Function importPackage must be called with a package; had "server.life.LifeFactory" instead. (<Unknown source>#46) in <Unknown source> at line number 46
2023-10-24 20:11:04.063 29240-29272 System.err              com.mapleserver                      W      at com.sun.script.javascript.RhinoScriptEngine.invoke(RhinoScriptEngine.java:330)
2023-10-24 20:11:04.065 29240-29272 System.err              com.mapleserver                      W      at com.sun.script.javascript.RhinoScriptEngine.invokeFunction(RhinoScriptEngine.java:288)
2023-10-24 20:11:04.065 29240-29272 System.err              com.mapleserver                      W      at scripting.SynchronizedInvocable.invokeFunction(SynchronizedInvocable.java:32)
2023-10-24 20:11:04.066 29240-29272 System.err              com.mapleserver                      W      at scripting.event.EventManager.lambda$schedule$0(EventManager.java:172)
2023-10-24 20:11:04.066 29240-29272 System.err              com.mapleserver                      W      at scripting.event.EventManager.$r8$lambda$AR51vuvnFxSsSXFZIGDAyGdIYwk(Unknown Source:0)
2023-10-24 20:11:04.066 29240-29272 System.err              com.mapleserver                      W      at scripting.event.EventManager$$ExternalSyntheticLambda0.run(Unknown Source:6)
2023-10-24 20:11:04.067 29240-29272 System.err              com.mapleserver                      W      at scripting.event.scheduler.EventScriptScheduler.runBaseSchedule(EventScriptScheduler.java:80)
2023-10-24 20:11:04.067 29240-29272 System.err              com.mapleserver                      W      at scripting.event.scheduler.EventScriptScheduler.lambda$new$0(EventScriptScheduler.java:47)
2023-10-24 20:11:04.068 29240-29272 System.err              com.mapleserver                      W      at scripting.event.scheduler.EventScriptScheduler.$r8$lambda$s8G568Z6xysfSNUGhJqxUwX71R0(Unknown Source:0)
2023-10-24 20:11:04.068 29240-29272 System.err              com.mapleserver                      W      at scripting.event.scheduler.EventScriptScheduler$$ExternalSyntheticLambda1.run(Unknown Source:2)
2023-10-24 20:11:04.068 29240-29272 System.err              com.mapleserver                      W      at server.TimerManager$LoggingSaveRunnable.run(TimerManager.java:145)
2023-10-24 20:11:04.068 29240-29272 System.err              com.mapleserver                      W      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:462)
2023-10-24 20:11:04.069 29240-29272 System.err              com.mapleserver                      W      at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:307)
2023-10-24 20:11:04.069 29240-29272 System.err              com.mapleserver                      W      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:302)

1. 修正importPackage用法 #

importPackage仅用于导入包，不能直接传入完整类名。正确写法：

importPackage(server.life);
const lifeFactory = LifeFactory; // 直接使用包内类名

2. 用importClass导入单个类 #

如果只需要导入特定类，改用importClass：

importClass(server.life.LifeFactory);
const lifeFactory = LifeFactory;

3. 确保类的可访问性 #

• 确认server.life.LifeFactory是public权限，非public类无法被Rhino访问。
• 检查代码混淆规则，在proguard-rules.pro中添加保留规则：

-keep class server.life.LifeFactory { *; }
// 如需保留整个包，可使用：
-keep class server.life.** { *; }

4. 配置Rhino类加载器 #

初始化脚本引擎时，设置正确的类加载器，让Rhino能找到项目类：

ScriptEngine engine = new ScriptEngineManager().getEngineByName("rhino");
if (engine instanceof RhinoScriptEngine) {
    ((RhinoScriptEngine) engine).setContextClassLoader(getClass().getClassLoader());
}

内容的提问来源于stack exchange，提问作者k0ala Xing