jsoup代码可在Java中工作，但不能在Android中工作-NullpointerException [英] jsoup code works in Java but not in Android- Nullpointerexception
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问题描述
我正在尝试使用jsoup编写一个刮天气的android应用.我有使用Java编写的代码，但即使是我可以在android中编写的最简单的形式，也会引发错误.这是我的代码的一部分:
I'm trying to write a weather scraping android app using jsoup. I have code working in Java, but even the simplest form I can write in android throws an error. Here's part of my code:
private class Retrieve_Weather extends AsyncTask<Void, Void, String> {
private final String TAG = "Retrieve_Weather";
protected String doInBackground(Void... params) {
String weatherline= "oTHErly";
Log.i(TAG, weatherline);
Document doc = null;
try {
Log.i(TAG, "trying document...");
doc = Jsoup.connect("http://m.wund.com/cgi-bin/findweather/getForecast?brand=mobile&query=02139").get();
Log.i(TAG, "after document");
weatherline = "newline";
}
catch (IOException except) {
Log.i(TAG, "Cannot Connect", except);
except.printStackTrace();
weatherline = "Can't Connect";
Log.i(TAG, "End stacktrace");
}
Log.i(TAG, weatherline);
return weatherline;
}
@Override
protected void onPreExecute() {
Log.i(TAG, "onPreExecute");
}
@Override
protected void onProgressUpdate(Void... values) {
Log.i(TAG, "onProgressUpdate");
}
@Override
protected void onPostExecute(String result){
//super.onPostExecute(result);
Log.i(TAG, "onPostExecute");
}
}
我已经使用了我的代码和logcat，足以弄清楚我的错误是运行.get()时抛出的nullpointerexception异常.我只是不知道为什么或如何解决它.这是我的堆栈跟踪:
I've played around with my code and logcat enough to figure out that my error is a nullpointerexception thrown when I run .get(). I just can't figure out why or how to fix it. Here's my stacktrace:
07-09 03:18:13.901: I/Retrieve_Weather(1754): trying document...
07-09 03:18:15.900: D/dalvikvm(1754): GC_CONCURRENT freed 80K, 7% free 2711K/2912K, paused 83ms+20ms, total 244ms
07-09 03:18:15.910: D/dalvikvm(1754): WAIT_FOR_CONCURRENT_GC blocked 157ms
07-09 03:18:16.351: D/dalvikvm(1754): GC_CONCURRENT freed 297K, 15% free 2841K/3340K, paused 81ms+124ms, total 329ms
07-09 03:18:16.740: W/dalvikvm(1754): Exception Ljava/lang/NullPointerException; thrown while initializing Lorg/jsoup/nodes/Entities;
07-09 03:18:16.740: W/dalvikvm(1754): Exception Ljava/lang/ExceptionInInitializerError; thrown while initializing Lorg/jsoup/nodes/Entities$EscapeMode;
07-09 03:18:16.810: W/System.err(1754): java.util.concurrent.ExecutionException: java.lang.ExceptionInInitializerError
07-09 03:18:16.830: W/System.err(1754): at java.util.concurrent.FutureTask.report(FutureTask.java:94)
07-09 03:18:16.830: W/System.err(1754): at java.util.concurrent.FutureTask.get(FutureTask.java:160)
07-09 03:18:16.860: W/System.err(1754): at android.os.AsyncTask.get(AsyncTask.java:482)
07-09 03:18:16.880: W/System.err(1754): at com.example.weatherresponse.Weather.onCreate(Weather.java:35)
07-09 03:18:16.880: W/System.err(1754): at android.app.Activity.performCreate(Activity.java:5104)
07-09 03:18:16.911: W/System.err(1754): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-09 03:18:16.911: W/System.err(1754): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-09 03:18:16.960: W/System.err(1754): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-09 03:18:16.970: W/System.err(1754): at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-09 03:18:16.970: W/System.err(1754): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-09 03:18:16.980: W/System.err(1754): at android.os.Handler.dispatchMessage(Handler.java:99)
07-09 03:18:16.990: W/System.err(1754): at android.os.Looper.loop(Looper.java:137)
07-09 03:18:16.990: W/System.err(1754): at android.app.ActivityThread.main(ActivityThread.java:5041)
07-09 03:18:16.990: W/System.err(1754): at java.lang.reflect.Method.invokeNative(Native Method)
07-09 03:18:17.010: W/System.err(1754): at java.lang.reflect.Method.invoke(Method.java:511)
07-09 03:18:17.061: W/System.err(1754): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-09 03:18:17.061: W/System.err(1754): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-09 03:18:17.061: W/System.err(1754): at dalvik.system.NativeStart.main(Native Method)
07-09 03:18:17.090: W/System.err(1754): Caused by: java.lang.ExceptionInInitializerError
07-09 03:18:17.090: W/System.err(1754): at org.jsoup.nodes.Document$OutputSettings.<init>(Document.java:210)
07-09 03:18:17.150: W/dalvikvm(1754): threadid=11: thread exiting with uncaught exception (group=0x40a71930)
07-09 03:18:17.150: W/System.err(1754): at org.jsoup.nodes.Document.<init>(Document.java:18)
07-09 03:18:17.160: W/System.err(1754): at org.jsoup.parser.TreeBuilder.initialiseParse(TreeBuilder.java:27)
07-09 03:18:17.160: W/System.err(1754): at org.jsoup.parser.TreeBuilder.parse(TreeBuilder.java:40)
07-09 03:18:17.160: W/System.err(1754): at org.jsoup.parser.HtmlTreeBuilder.parse(HtmlTreeBuilder.java:37)
07-09 03:18:17.170: W/System.err(1754): at org.jsoup.parser.Parser.parseInput(Parser.java:30)
07-09 03:18:17.170: W/System.err(1754): at org.jsoup.helper.DataUtil.parseByteData(DataUtil.java:102)
07-09 03:18:17.170: W/System.err(1754): at org.jsoup.helper.HttpConnection$Response.parse(HttpConnection.java:498)
07-09 03:18:17.215: W/System.err(1754): at org.jsoup.helper.HttpConnection.get(HttpConnection.java:154)
07-09 03:18:17.215: W/System.err(1754): at com.example.weatherresponse.Weather$Retrieve_Weather.doInBackground(Weather.java:85)
07-09 03:18:17.220: W/System.err(1754): at com.example.weatherresponse.Weather$Retrieve_Weather.doInBackground(Weather.java:1)
07-09 03:18:17.220: W/System.err(1754): at android.os.AsyncTask$2.call(AsyncTask.java:287)
07-09 03:18:17.230: W/System.err(1754): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
07-09 03:18:17.230: W/System.err(1754): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
07-09 03:18:17.240: W/System.err(1754): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
07-09 03:18:17.240: W/System.err(1754): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
07-09 03:18:17.240: W/System.err(1754): at java.lang.Thread.run(Thread.java:856)
07-09 03:18:17.260: W/System.err(1754): Caused by: java.lang.ExceptionInInitializerError
07-09 03:18:17.290: W/System.err(1754): at org.jsoup.nodes.Entities$EscapeMode.<clinit>(Entities.java:20)
07-09 03:18:17.290: W/System.err(1754): ... 17 more
07-09 03:18:17.290: W/System.err(1754): Caused by: java.lang.NullPointerException: in == null
07-09 03:18:17.290: W/System.err(1754): at java.util.Properties.load(Properties.java:246)
07-09 03:18:17.290: W/System.err(1754): at org.jsoup.nodes.Entities.loadEntities(Entities.java:151)
07-09 03:18:17.290: W/System.err(1754): at org.jsoup.nodes.Entities.<clinit>(Entities.java:135)
07-09 03:18:17.290: W/System.err(1754): ... 18 more
07-09 03:18:17.383: I/System.out(1754): ExecExceptjava.lang.ExceptionInInitializerError
07-09 03:18:19.570: E/AndroidRuntime(1754): FATAL EXCEPTION: AsyncTask #1
07-09 03:18:19.570: E/AndroidRuntime(1754): java.lang.RuntimeException: An error occured while executing doInBackground()
07-09 03:18:19.570: E/AndroidRuntime(1754): at android.os.AsyncTask$3.done(AsyncTask.java:299)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.FutureTask.run(FutureTask.java:239)
07-09 03:18:19.570: E/AndroidRuntime(1754): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.lang.Thread.run(Thread.java:856)
07-09 03:18:19.570: E/AndroidRuntime(1754): Caused by: java.lang.ExceptionInInitializerError
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.nodes.Document$OutputSettings.<init>(Document.java:210)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.nodes.Document.<init>(Document.java:18)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.parser.TreeBuilder.initialiseParse(TreeBuilder.java:27)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.parser.TreeBuilder.parse(TreeBuilder.java:40)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.parser.HtmlTreeBuilder.parse(HtmlTreeBuilder.java:37)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.parser.Parser.parseInput(Parser.java:30)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.helper.DataUtil.parseByteData(DataUtil.java:102)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.helper.HttpConnection$Response.parse(HttpConnection.java:498)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.helper.HttpConnection.get(HttpConnection.java:154)
07-09 03:18:19.570: E/AndroidRuntime(1754): at com.example.weatherresponse.Weather$Retrieve_Weather.doInBackground(Weather.java:85)
07-09 03:18:19.570: E/AndroidRuntime(1754): at com.example.weatherresponse.Weather$Retrieve_Weather.doInBackground(Weather.java:1)
07-09 03:18:19.570: E/AndroidRuntime(1754): at android.os.AsyncTask$2.call(AsyncTask.java:287)
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
07-09 03:18:19.570: E/AndroidRuntime(1754): ... 4 more
07-09 03:18:19.570: E/AndroidRuntime(1754): Caused by: java.lang.ExceptionInInitializerError
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.nodes.Entities$EscapeMode.<clinit>(Entities.java:20)
07-09 03:18:19.570: E/AndroidRuntime(1754): ... 17 more
07-09 03:18:19.570: E/AndroidRuntime(1754): Caused by: java.lang.NullPointerException: in == null
07-09 03:18:19.570: E/AndroidRuntime(1754): at java.util.Properties.load(Properties.java:246)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.nodes.Entities.loadEntities(Entities.java:151)
07-09 03:18:19.570: E/AndroidRuntime(1754): at org.jsoup.nodes.Entities.<clinit>(Entities.java:135)
07-09 03:18:19.570: E/AndroidRuntime(1754): ... 18 more
除了这一行基本代码外，我的代码可以正常运行.我已经在模拟器和Android手机上测试了我的代码，并且都可以访问互联网.我试过多个网站，以及这些网站的移动版本，但没有一个起作用.我的清单和库文件都在正确的位置具有Internet权限.我在这个站点和其他站点上到处都是关于我的问题的解决方案.由于在相关帖子中找到了我所修改的代码和权限，但是我还没有找到适合我的已回答帖子.但是，我发现了一些未回答的帖子，它们提出了完全相同的问题.我发现我没有尝试过的唯一答案是对此问题错误使用AsyncTask和Jsoup发布APK时:我无法找出更改该文件的文件来测试它是否解决了我的问题.我是编程新手，将不胜感激.谢谢！
My code runs correctly except for this single, basic line. I've tested my code on both an emulator and an android phone, and both had internet access. I've tried multiple websites, and the mobile versions of those websites, but none have worked. I have internet permissions in my manifests and my library files in the correct place. I've looked around a lot on this site and others for solutions to my problem. I've modified my code and permissions due to what I've found in related posts, but I have yet to find an answered post that works for me. I have, however, found a few unanswered posts that ask the exact same question. The only answer I found that I haven't tried is to this question Error when releasing APK with AsyncTask and Jsoup: I can't figure out which file to change this in to test if it solve my issue. I'm fairly new to programming- any help would be greatly appreciated. Thanks!
推荐答案
我的代码现在可以使用了！我最终将.jar文件移动到lib中，而不是按照
My code works now! I ended up moving my .jar file into lib instead of using it as a referenced external jar, as recommended in Android-SDK r17 ruins working projects. I also added a user agent and reworked my AsyncTask so that Jsoup.connect(url) is in onPreExecute while leaving .get() in doInBackground.
private class Retrieve_Weather extends AsyncTask<Void, Void, String> {
private final String TAG = "Retrieve_Weather";
Connection con = null;
protected Void doInBackground(String... params) {
//Log.i(TAG, weatherline);
Document doc = null;
if (con !=null){
try {
Log.i(TAG, "trying document...");
doc = con.get();
Log.i(TAG, "after document");
Element currentWeather = doc.getElementById("curCond");
currentweather = currentWeather.text();
Log.i(TAG, currentWeather.text());
}
catch (IOException except) {
Log.i(TAG, "Cannot Connect", except);
except.printStackTrace();
currentweather = "Can't Connect";
Log.i(TAG, "End stacktrace");
}
}
else{
currentweather = "Connection returned null";
}
//Log.i(TAG, weatherline);
return currentweather;
}
@Override
protected void onPreExecute() {
//Log.i(TAG, "onPreExecute");
Log.i(TAG, "trying to connect...");
con = Jsoup.connect("http://www.wunderground.com/cgi-bin/findweather/getForecast?query=zmw:02142.1.99999").userAgent("Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0");
Log.i(TAG, "CONNECTED!!!");
}
@Override
protected void onProgressUpdate(Void... values) {
Log.i(TAG, "onProgressUpdate");
}
@Override
protected void onPostExecute(Void result){
Log.i(TAG, "onPostExecute");
}
}
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