DataBinding - 踩坑记

1. Didn't find class "android.databinding.DataBinderMapperImpl"

项目加入dataBinding之后编译运行，在Activity页面跳转时报了个错误：

java.lang.NoClassDefFoundError: Failed resolution of: Landroid/databinding/DataBinderMapperImpl;
        at android.databinding.DataBindingUtil.<clinit>(DataBindingUtil.java:32)
        at com.xxx.gui.BaseActivity.initViewDataBinding(BaseActivity.java:151)
        at com.xxx.gui.BaseActivity.onCreate(BaseActivity.java:79)
        at android.app.Activity.performCreate(Activity.java:6222)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407)
        at android.app.ActivityThread.access$800(ActivityThread.java:151)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1319)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5280)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:963)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:758)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "android.databinding.DataBinderMapperImpl" on path: DexPathList[[zip file "/data/app/com.xxx.xxx-1/base.apk"],nativeLibraryDirectories=[/data/app/com.xxx.xxx-1/lib/arm, /vendor/lib, /system/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
        at android.databinding.DataBindingUtil.<clinit>(DataBindingUtil.java:32) 
        at com.xxx.gui.BaseActivity.initViewDataBinding(BaseActivity.java:151) 
        at com.xxx.gui.BaseActivity.onCreate(BaseActivity.java:79) 
        at android.app.Activity.performCreate(Activity.java:6222) 
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295) 
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407) 
        at android.app.ActivityThread.access$800(ActivityThread.java:151) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1319) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:135) 
        at android.app.ActivityThread.main(ActivityThread.java:5280) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:372) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:963) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:758) 
        Suppressed: java.lang.ClassNotFoundException: android.databinding.DataBinderMapperImpl
        at java.lang.Class.classForName(Native Method)
        at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
        at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
                ... 17 more
     Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

几番搜索之后发现是gradle配置问题，由于项目中包含了多个子module，某个Activity所在的module没有配置dataBinding导致的。

 dataBinding {
        enabled = true
 }