实在是找不到原因了！java.lang.NullPointerException

Question

先弄清楚是那个对象报的NullPointerException ，mImageLoader? mImageIds?

Answer 1

mImageLoader在构造中new了，不可能为空
改成下面这个，如果还有空指针，就是mImageLoader.get里的问题了
mImageLoader.get(""+mImageIds[position], listener);

Answer 2

把报错信息给贴出来，nullpointer很好确认的

Answer 3

我把报错日志全部贴出来了，mImageLoader.get(""+mImageIds[position], listener);  用了这个还是不行，报错也在这一行
08-05 23:08:32.614: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:32.614: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:33.916: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:33.916: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.126: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.126: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.336: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.336: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.847: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:34.847: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:35.898: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:35.898: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:36.128: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:36.128: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:36.308: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:36.308: E/SpannableStringBuilder(31636): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
08-05 23:08:37.860: E/AndroidRuntime(31636): FATAL EXCEPTION: main
08-05 23:08:37.860: E/AndroidRuntime(31636): Process: cn.phonecms.main, PID: 31636
08-05 23:08:37.860: E/AndroidRuntime(31636): java.lang.NullPointerException
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.volley.Request.<init>(Request.java:129)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.volley.toolbox.ImageRequest.<init>(ImageRequest.java:71)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:220)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:171)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at cn.phonecms.main.ManageProduct$CatergorAdapter.getView(ManageProduct.java:128)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.AbsListView.obtainView(AbsListView.java:2715)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.ListView.onMeasure(ListView.java:1158)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5352)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1410)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.ScrollView.measureChildWithMargins(ScrollView.java:1759)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.ScrollView.onMeasure(ScrollView.java:468)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5352)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1410)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5352)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5352)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2533)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.View.measure(View.java:17387)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2211)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1350)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1547)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1234)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6465)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:803)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.Choreographer.doCallbacks(Choreographer.java:603)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.Choreographer.doFrame(Choreographer.java:573)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:789)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.os.Handler.handleCallback(Handler.java:733)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.os.Handler.dispatchMessage(Handler.java:95)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.os.Looper.loop(Looper.java:157)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at android.app.ActivityThread.main(ActivityThread.java:5356)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at java.lang.reflect.Method.invokeNative(Native Method)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at java.lang.reflect.Method.invoke(Method.java:515)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
08-05 23:08:37.860: E/AndroidRuntime(31636):  at dalvik.system.NativeStart.main(Native Method)

Answer 4

我的一篇博客，可以学习学习：
http://blog.csdn.net/gao_chun/article/details/34117083

Answer 5

你需要在你这个应用程序中配置一些相关的Volley设置项，你应该没有配置。
比如在你的程序里面配置一下
Volley.newRequestQueue这个方法试试，如果还不行，你看看volley还有其他什么要配置的

Answer 6

//适配显示的图片数组
  private Integer[] mImageIds = {R.drawable.catergory_appliance,R.drawable.catergory_book    };
这个放到前面定义

Answer 7

我找到原因了，get里面的第一个参数是string的url，但是如上代码我传递的是R.***.*** 这个是16进制的整数，所以第一个参数不能识别，导致的，我改成如下的话，就不会报错
  private String[] mImageIds = {"http://imgstatic.baidu.com/img/image/shouye/fanbingbing.jpg","http://imgstatic.baidu.com/img/image/shouye/liuyifei.jpg","http://imgstatic.baidu.com/img/image/shouye/wanglihong.jpg","http://imgstatic.baidu.com/img/image/shouye/gaoyuanyuan.jpg",
      "http://imgstatic.baidu.com/img/image/shouye/yaodi.jpg","http://imgstatic.baidu.com/img/image/shouye/zhonghanliang.jpg","http://imgstatic.baidu.com/img/image/shouye/xiezhen.jpg","http://imgstatic.baidu.com/img/image/shouye/yiping3.jpg"
       };
现在又遇到一个问题就是，当用如下代码显示图片的时候，第一次运行，图片都能显示，但是到了下次再次运行该页面，图片要么显示android.R.drawable.ic_menu_rotate，要么显示android.R.drawable.ic_delete，就是不显示正常图片ImageListener listener = ImageLoader.getImageListener(imageView, android.R.drawable.ic_menu_rotate, android.R.drawable.ic_delete);