java - NullPointerException : Attempt to invoke virtual method 'void org. apache.cordova.CordovaPlugin.privateInitialize

Question

我正在对我的 cordova 插件进行一些重构，但我开始在启动时崩溃:

--------- beginning of crash
12-12 21:42:29.791  4693  4693 E AndroidRuntime: FATAL EXCEPTION: main
12-12 21:42:29.791  4693  4693 E AndroidRuntime: Process: xyz.meris.app, PID: 4693
12-12 21:42:29.791  4693  4693 E AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{xyz.meris.app/xyz.meris.app.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void org.apache.cordova.CordovaPlugin.privateInitialize(java.lang.String, org.apache.cordova.CordovaInterface, org.apache.cordova.CordovaWebView, org.apache.cordova.CordovaPreferences)' on a null object reference
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3162)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3305)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1993)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.os.Handler.dispatchMessage(Handler.java:106)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.os.Looper.loop(Looper.java:216)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.ActivityThread.main(ActivityThread.java:7266)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at java.lang.reflect.Method.invoke(Native Method)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
12-12 21:42:29.791  4693  4693 E AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void org.apache.cordova.CordovaPlugin.privateInitialize(java.lang.String, org.apache.cordova.CordovaInterface, org.apache.cordova.CordovaWebView, org.apache.cordova.CordovaPreferences)' on a null object reference
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.PluginManager.getPlugin(PluginManager.java:171)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.PluginManager.startupPlugins(PluginManager.java:97)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.PluginManager.init(PluginManager.java:86)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.CordovaWebViewImpl.init(CordovaWebViewImpl.java:117)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.CordovaActivity.init(CordovaActivity.java:149)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at org.apache.cordova.CordovaActivity.loadUrl(CordovaActivity.java:224)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at xyz.meris.app.MainActivity.onCreate(MainActivity.java:39)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.Activity.performCreate(Activity.java:7353)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.Activity.performCreate(Activity.java:7344)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1275)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3142)
12-12 21:42:29.791  4693  4693 E AndroidRuntime:    ... 11 more
12-12 21:42:29.826  4693  4693 I Process : Sending signal. PID: 4693 SIG: 9

我四处寻找，发现了一些类似的问题:

• > android onActivityResult: Attempt to invoke virtual method on a null object reference
• > Class Not Found Exception using custom cordova plugin

但解决方案对我不起作用...

Answer 1

我从其他问题中得到了一些线索，因为我正在重构，所以我一直在使用 plugin.xml文件。

我注意到我与其他人有这个区别 plugin.xml文件:

      <feature name="CDVProcessLog">
        <param name="android-package" value="xyz.meris.processlog.CDVProcessLog" />
        <param name="onload" value="true" />
      </feature>
      <feature name="ProcessLog">
        <param name="android-package" value="xyz.meris.processlog.ProcessLog" />
+       <param name="onload" value="true" />
      </feature>

因为我复制了<feature>标签并填入我复制了onload范围。一旦我删除了重复项 onload崩溃停止发生的参数。

编辑:企业资源计划原来我有另一个错误导致了这个问题。

删除 onload参数延迟加载 ProcessLog .所以我稍后会得到一个空指针错误。

我真正的问题是我的 .js文件没有用我的 CordovaPlugin 更新类(class)名称。我已经从 ProcessLog 更改了它至 CDVProcessLog . ProcessLog现在有了处理日志的细节和CDVProcessLog在 ProcessLog 中主要使用 cordova 胶水来调用我的方法.

我的 .js需要更改的文件:

  return new Promise((resolve, reject) => {
-    exec(resolve, reject, 'ProcessLog', func, [...args]);
+    exec(resolve, reject, 'CDVProcessLog', func, [...args]);
  });