为什么我会收到一个致命异常？ [英] Why am I receiving a fatal exception?
问题描述
我是新来的Android和我想创建一个列表视图中使用数组适配器，运行方法和多线程，但我收到以下错误
07-14 19：00：15.605 29316-29316 / com.protogeo.moves.demos.apps
W / dalvikvm：主题ID = 1：螺纹未捕获的异常退出
（组= 0xa4b8f648）07-14 19：00：15.633
29316-29316 / com.protogeo.moves.demos.apps E / AndroidRuntime：FATAL
例外：主
显示java.lang.NullPointerException
在android.widget.ArrayAdapter.getCount（ArrayAdapter.java:330）
在android.widget.ListView.onMeasure（ListView.java:1128）
在android.view.View.measure（View.java:15848）
在android.widget.RelativeLayout.measureChildHorizontal（RelativeLayout.java:728）
在android.widget.RelativeLayout.onMeasure（RelativeLayout.java:477）
在android.view.View.measure（View.java:15848）
在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5012）
在android.widget.FrameLayout.onMeasure（FrameLayout.java:310）
在android.view.View.measure（View.java:15848）
在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5012）
在com.android.internal.widget.ActionBarOverlayLayout.onMeasure（ActionBarOverlayLayout.java:302）
在android.view.View.measure（View.java:15848）
在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5012）
在android.widget.FrameLayout.onMeasure（FrameLayout.java:310）
在com.android.internal.policy.impl.PhoneWindow $ DecorView.onMeasure（PhoneWindow.java:2189）
在android.view.View.measure（View.java:15848）
在android.view.ViewRootImpl.performMeasure（ViewRootImpl.java:1905）
在android.view.ViewRootImpl.measureHierarchy（ViewRootImpl.java:1104）
在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:1284）
在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1004）
在android.view.ViewRootImpl $ TraversalRunnable.run（ViewRootImpl.java:5481）
在android.view.Choreographer $ CallbackRecord.run（Choreographer.java:749）
在android.view.Choreographer.doCallbacks（Choreographer.java:562）
在android.view.Choreographer.doFrame（Choreographer.java:532）
在android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:735）
在android.os.Handler.handleCallback（Handler.java:730）
在android.os.Handler.dispatchMessage（Handler.java:92）
在android.os.Looper.loop（Looper.java:137）
在android.app.ActivityThread.main（ActivityThread.java:5103）
在java.lang.reflect.Method.invokeNative（本机方法）
在java.lang.reflect.Method.invoke（Method.java:525）
在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:737）
在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:553）
在dalvik.system.NativeStart.main（本机方法）我的
MainActivity是这样的：公共类MainActivity扩展FragmentActivity实现OnClickListener {
...
公共无效updateResponse（）{
runOnUiThread（新的Runnable（）{
@覆盖
公共无效的run（）{
StorylineAdapter适配器= NULL;
尝试{
适配器=新StorylineAdapter（MainActivity.this，R.layout.item_storyline，总结）; // mEditTextResponse.setAdapter（适配器）;
mEditTextResponse.setAdapter（适配器）;
}赶上（例外五）{
e.printStackTrace（）;
}我的
ArrayAdapter类看起来是这样的：公共类StorylineAdapter扩展ArrayAdapter＆LT; SummaryData＆GT; {
私人上下文的背景下;
私人Runnable接口可运行;
私人的ArrayList＆LT; StorylineData＆GT; storylineData;公共StorylineAdapter（上下文的背景下，INT资源的ArrayList＆LT; SummaryData＆GT;对象）{
超级（上下文，资源，对象）;
this.context =背景;
this.runnable =可运行;
this.summary =物体;
}@覆盖
公共查看getView（INT位置，查看convertView，父母的ViewGroup）{ LayoutInflater吹气=（LayoutInflater）context.getSystemService（Activity.LAYOUT_INFLATER_SERVICE）;
查看查看= inflater.inflate（R.layout.item_storyline，父母，假）;
/ * LayoutInflater吹气=
（LayoutInflater）getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
查看查看= inflater.inflate（R.layout.item_storyline，父母，假）;
* / //显示在TextView的小部件
SummaryData summary1 = summary.get（位置）;
TextView的电视=（TextView中）view.findViewById（R.id.textView1）;
tv.setText（summary1.getActivity（））; 返回视图。
}
}下面是我的分析器类：
公共类StorylineData扩展的ArrayList＆LT; StorylineData＆GT; {... getter / setter方法... / ** *******************解析器方法 / **
*解析一个{@link org.json.JSONObject}从故事情节{@link org.json.JSONArray}，然后返回相应的{@link StorylineData}对象。
*
* @参数的JSONObject：从服务器接收到的故事情节JSON对象
* @返回相应的{@link StorylineData}
* /
公共静态StorylineData解析（JSONObject的JSONObject的）抛出JSONException {
如果（JSONObject的！= NULL）{ StorylineData storylineData =新StorylineData（）;
storylineData.date = jsonObject.optString（日期）;
storylineData.caloriesIdle = jsonObject.optInt（caloriesIdle）;
storylineData.lastUpdate = jsonObject.optString（LASTUPDATE）;
storylineData.summary =新的ArrayList＆LT; SummaryData＆GT;（）;
storylineData.segments =新的ArrayList＆LT; SegmentData＆GT;（）; / **获取与命名总结阵列**相关的数据获取特定的JSONArray：摘要* /
JSONArray summariesJsonArray = jsonObject.optJSONArray（摘要）; 如果（summariesJsonArray！= NULL）
的for（int i = 0; I＆LT; summariesJsonArray.length（）;我++）{
/ **通过阵列每次需要获得当前对象*的参考/
JSONObject的summaryJsonObject = summariesJsonArray.optJSONObject（我）; //声明类对象实例OB //称为getJSONObject //将经过的indexvalu数组对象（一） 如果（summaryJsonObject！= NULL）{
/ ** ===============从JSON到Java转换数据================= * /
/ **创建阵列故事情节/概述的新对象* /
ArrayList的＆LT; SummaryData＆GT;总结=新的ArrayList＆LT; SummaryData＆GT;（）; //初始化必须是外循环
storylineData.setSummary（摘要）; / **获取从JSON汇总到Java * /
summariesJsonArray.getJSONObject（ⅰ）.getString（距离）; / **从JSON到Java获取日期* /
字符串日期= summaryJsonObject.optString（日期）;
storylineData.setDate（日期）; / **从JSON到Java获取组* /
串组= summaryJsonObject.optString（本集团）; //使用key例如获取名称日期
storylineData.setGroup（组）; / **获取从JSON距离为Java * /
整数距离= summaryJsonObject.optInt（距离）; //使用key例如获取名称日期
storylineData.setDistance（距离）; / **从JSON到Java获取时间* /
整型持续时间= summaryJsonObject.optInt（时间）;
storylineData.setDuration（持续时间）; / **从JSON到Java获取活动* /
串活性= summaryJsonObject.optString（活动）; //使用key例如获取名称日期
storylineData.setActivity（活动）;
storylineData.summary.add（SummaryData.parse（summaryJsonObject））;
Log.d（StorylineDataCls \\ t SJO，summaryJsonObject.toString（）+日志\\ n）;
的System.out.println（打印距离+ summariesJsonArray.getJSONObject㈠.getString（距离））;
的System.out.println（打印摘要+ summaryJsonObject）;
}
} JSONArray segmentsJsonArray = jsonObject.optJSONArray（段）;
如果（segmentsJsonArray！= NULL）{ 的for（int i = 0; I＆LT; segmentsJsonArray.length（）;我++）{
的JSONObject段= segmentsJsonArray.optJSONObject（ⅰ）; 如果（段！= NULL）{ ArrayList的＆LT; SegmentData＆GT;段=新的ArrayList＆LT; SegmentData＆GT;（）; //初始化必须是外循环
storylineData.setSegments（段）; 字符串类型= segment.optString（类型）;
storylineData.setType（类型）; 字符串STARTTIME = segment.optString（startTime时）;
storylineData.setStartTime（startTime时）;
串ENDTIME = segment.optString（ENDTIME）;
storylineData.setEndTime（结束时间）; / **获取从JSON步骤为Java * /
整活动= segment.optInt（地方）;
storylineData.setSteps（活动）;
整数热量= segment.optInt（卡路里）;
storylineData.setCalories（卡路里）; 字符串LASTUPDATE = segment.optString（LASTUPDATE）;
storylineData.setLastUpdate（LASTUPDATE）;
/ **从JSON到Java获取组* /
整数caloriesIdle = segment.optInt（caloriesIdle）;
storylineData.setCaloriesIdle（caloriesIdle）; storylineData.segments.add（SegmentData.parse（段））;
Log.d（StorylineDataCls \\ t SSO，segment.toString（））; }
}
}
返回storylineData;
}
返回null;
}}
解决方案看起来像摘要为空。创建和设置适配器之前检查空。
如果（概要== NULL）{
//处理错误
Toast.makeText（这一点，错误：没有结果，Toast.LENGTH_LONG）.show（）;
}其他{
StorylineAdapter适配器=新StorylineAdapter（MainActivity.this，R.layout.item_storyline，总结）;
mEditTextResponse.setAdapter（适配器）;
}I am new to android and I am trying to create a list view using an array adapter, a run method and
multi threading, but I'm receiving the following error:07-14 19:00:15.605 29316-29316/com.protogeo.moves.demos.apps W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xa4b8f648) 07-14 19:00:15.633 29316-29316/com.protogeo.moves.demos.apps E/AndroidRuntime﹕ FATAL EXCEPTION: main java.lang.NullPointerException at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330) at android.widget.ListView.onMeasure(ListView.java:1128) at android.view.View.measure(View.java:15848) at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728) at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477) at android.view.View.measure(View.java:15848) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012) at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) at android.view.View.measure(View.java:15848) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012) at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:302) at android.view.View.measure(View.java:15848) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012) at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189) at android.view.View.measure(View.java:15848) at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905) at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) at android.view.Choreographer.doCallbacks(Choreographer.java:562) at android.view.Choreographer.doFrame(Choreographer.java:532) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) at android.os.Handler.handleCallback(Handler.java:730) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5103) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) at dalvik.system.NativeStart.main(Native Method)
My
MainActivitylooks like this:public class MainActivity extends FragmentActivity implements OnClickListener{ ... public void updateResponse() { runOnUiThread(new Runnable() { @Override public void run() { StorylineAdapter adapter = null; try { adapter = new StorylineAdapter(MainActivity.this, R.layout.item_storyline, summary); // mEditTextResponse.setAdapter(adapter); mEditTextResponse.setAdapter(adapter); } catch (Exception e) { e.printStackTrace(); }My
ArrayAdapterclass looks like this:public class StorylineAdapter extends ArrayAdapter<SummaryData>{ private Context context; private Runnable runnable; private ArrayList<StorylineData> storylineData; public StorylineAdapter(Context context, int resource, ArrayList<SummaryData> objects) { super(context, resource, objects); this.context = context; this.runnable = runnable; this.summary = objects; } @Override public View getView(int position, View convertView, ViewGroup parent){ LayoutInflater inflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout.item_storyline, parent, false); /*LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout.item_storyline, parent, false); */ //Display in the TextView widget SummaryData summary1 = summary.get(position); TextView tv = (TextView) view.findViewById(R.id.textView1); tv.setText(summary1.getActivity()); return view; } }Here is my parser class:
public class StorylineData extends ArrayList<StorylineData> { ...Getters/Setters... /** ******************* Parser methods /** * Parse a {@link org.json.JSONObject} from storyline {@link org.json.JSONArray}, then return the corresponding {@link StorylineData} object. * * @param jsonObject : the storyline JSON object received from server * @return corresponding {@link StorylineData} */ public static StorylineData parse(JSONObject jsonObject) throws JSONException { if (jsonObject != null) { StorylineData storylineData = new StorylineData(); storylineData.date = jsonObject.optString("date"); storylineData.caloriesIdle = jsonObject.optInt("caloriesIdle"); storylineData.lastUpdate = jsonObject.optString("lastUpdate"); storylineData.summary = new ArrayList<SummaryData>(); storylineData.segments = new ArrayList<SegmentData>(); /**Get the data associated with the array named summary **To get a specific JSONArray: Summary*/ JSONArray summariesJsonArray = jsonObject.optJSONArray("summary"); if (summariesJsonArray != null) for (int i = 0; i < summariesJsonArray.length(); i++) { /**each time through array will need to get a reference of current object*/ JSONObject summaryJsonObject = summariesJsonArray.optJSONObject(i);//declare instance of class object ob //array object called getJSONObject //passin indexvalu of (i) if (summaryJsonObject != null) { /**===============Translate data from json to Java=================*/ /**Create a new OBJECT OF ARRAY STORYLINE/SUMMARY*/ ArrayList<SummaryData> summary = new ArrayList<SummaryData>(); // initialisation must be outside the loop storylineData.setSummary(summary); /**Get summary from json into java*/ summariesJsonArray.getJSONObject(i).getString("distance"); /**Get date from json into java*/ String date = summaryJsonObject.optString("date"); storylineData.setDate(date); /**Get group from json into java*/ String group = summaryJsonObject.optString("group");//Get name using key e.g. date storylineData.setGroup(group); /**Get distance from json into java*/ Integer distance = summaryJsonObject.optInt("distance");//Get name using key e.g. date storylineData.setDistance(distance); /**Get duration from json into java*/ Integer duration = summaryJsonObject.optInt("duration"); storylineData.setDuration(duration); /**Get activity from json into java*/ String activity = summaryJsonObject.optString("activity");//Get name using key e.g. date storylineData.setActivity(activity); storylineData.summary.add(SummaryData.parse(summaryJsonObject)); Log.d("StorylineDataCls \t sJo", summaryJsonObject.toString() + "Log\n"); System.out.println("print distance" + summariesJsonArray.getJSONObject(i).getString("distance")); System.out.println("print summary" + summaryJsonObject); } } JSONArray segmentsJsonArray = jsonObject.optJSONArray("segments"); if (segmentsJsonArray != null) { for (int i = 0; i < segmentsJsonArray.length(); i++) { JSONObject segment = segmentsJsonArray.optJSONObject(i); if (segment != null) { ArrayList<SegmentData> segments = new ArrayList<SegmentData>(); // initialisation must be outside the loop storylineData.setSegments(segments); String type = segment.optString("type"); storylineData.setType(type); String startTime = segment.optString("startTime"); storylineData.setStartTime(startTime); String endTime = segment.optString("endTime"); storylineData.setEndTime(endTime); /**Get steps from json into java*/ Integer activities = segment.optInt("place"); storylineData.setSteps(activities); Integer calories = segment.optInt("calories"); storylineData.setCalories(calories); String lastUpdate = segment.optString("lastUpdate"); storylineData.setLastUpdate(lastUpdate); /**Get group from json into java*/ Integer caloriesIdle = segment.optInt("caloriesIdle"); storylineData.setCaloriesIdle(caloriesIdle); storylineData.segments.add(SegmentData.parse(segment)); Log.d("StorylineDataCls \t sSo", segment.toString()); } } } return storylineData; } return null; } }
解决方案Looks like "summary" is null. Check for null before creating and setting the adapter.
if (summary == null) { // handle the error Toast.makeText(this, "Error: no result", Toast.LENGTH_LONG).show(); } else { StorylineAdapter adapter = new StorylineAdapter(MainActivity.this, R.layout.item_storyline, summary); mEditTextResponse.setAdapter(adapter); }
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