問題描述
所以我認為我在以前的帖子中質疑了錯誤的方式.我最好這樣說.我正在嘗試解析 XML 數據:
So I think I was questioning the wrong way in previous threads. I better put it like this. I'm trying to parse the XML data:
<playlist>
<title>![CDATA[New Playlist]]</title>
<items>
<item>
<title>HAMD(LA ILAHA ILLALLAH)</title>
<description>Recited By :Alhaaj Muhammad Owais Raza Qadri -- Written By: Mufti-e-Azam Hind Molana Mustafa Raza Khan Noori</description>
<image>http://xxx.xxx.xxx.xxx/~kanz/video/Images/9.jpg</image>
<startFromThis>true</startFromThis>
<duration>510</duration>
<source>http://xxx.xxx.xxx.xxx/~kanz/video/flv/9.flv</source>
<sourceAlt>http://xxx.xxx.xxx.xxx/~kanz/video/mp4/9.mp4</sourceAlt>
<sourceType>direct</sourceType>
</item>
</items>
</playlist>
在我的活動中，我所做的是這樣，但 logcat 給出了空指針異常.這是我的活動，下面是 logcat 錯誤.
In my Activity, what I did was this but the logcat gives null pointer exception. Here's my Activity and below it the logcat error.
static final String URL = "http://xxx.xxx.xxx.xxx/~kanz/video/XML/9.xml";
// XML node keyse.
static final String KEY_SONG = "item"; // parent node
static final String KEY_TITLE = "title";
static final String KEY_ARTIST = "description";
static final String KEY_THUMB_URL = "image";
static final String KEY_DURATION = "duration";
NodeList nl = doc.getElementsByTagName(KEY_SONG);
// looping through all song nodes <song>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap <String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
// adding HashList to ArrayList
songsList.add(map);
}
Logcat 給出 Unexpected Token 錯誤并返回 null 導致空指針異常.
Logcat gives Unexpected Token error and returns null which causes null pointer exception.
03-28 14:31:34.059: E/Error:(895): Unexpected token (position:TEXT ???@1:4 in java.io.StringReader@40d220e0)
03-28 14:31:34.080: I/System.out(895): null
03-28 14:42:59.560: D/AndroidRuntime(978): Shutting down VM
03-28 14:42:59.560: W/dalvikvm(978): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
03-28 14:42:59.639: E/AndroidRuntime(978): FATAL EXCEPTION: main
03-28 14:42:59.639: E/AndroidRuntime(978): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.razatubevidurl/com.example.razatubevidurl.CustomizedListView}: java.lang.NullPointerException
03-28 14:42:59.639: E/AndroidRuntime(978): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.os.Handler.dispatchMessage(Handler.java:99)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.os.Looper.loop(Looper.java:137)
03-28 14:42:59.639: E/AndroidRuntime(978): at android.app.ActivityThread.main(ActivityThread.java:5041)
03-28 14:42:59.639: E/AndroidRuntime(978): at java.lang.reflect.Method.invokeNative(Native Method)
03-28 14:42:59.639: E/AndroidRuntime(978): at java.lang.reflect.Method.invoke(Method.java:511)
03-28 14:42:59.639: E/AndroidRuntime(978): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-28 14:42:59.639: E/AndroidRuntime(978): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-28 14:42:59.639: E/AndroidRuntime(978): at dalvik.system.NativeStart.main(Native Method)
03-28 14:42:59.639: E/AndroidRuntime(978): Caused by: java.lang.NullPointerException
請告訴我我做錯了什么.我認為我之前的問題含糊不清，在這一個問題中，我盡力使問題清晰易懂.
Please tell me what I'm doing wrong. I thought my previous question was vague and in this one, I tried my best to make the question clear and understandable.
推薦答案
我猜這和編碼有關.也許您的解析器不喜歡感嘆號 (!).您能否確保使用正確編碼的 XML 文件?(UTF-8)
I guess it's something about encoding. Maybe your parser doesn't like the exclamation mark (!). Can you make sure that you use the XML file with the correct encoding? (UTF-8)
否則，你有這個問題:KXmlParser 拋出意外的令牌"；RSS 開始時的異常.
Otherwise, you have this problem: KXmlParser throws "Unexpected token" exception at the start of RSS pasing.
我搜索了一下，看起來最簡單的解決方法是 這里.您可以嘗試添加此方法.(根據您使用的教程，將其放在 ImageLoader 類中.)
I googled around and it looks like the easiest fix is here. You can try adding this method. (From the tutorial you use, put this in the ImageLoader class.)
import java.io.PushbackInputStream;
private InputStream checkForUtf8BOMAndDiscardIfAny(InputStream inputStream) throws IOException {
PushbackInputStream pushbackInputStream = new PushbackInputStream(new BufferedInputStream(inputStream), 3);
byte[] bom = new byte[3];
if (pushbackInputStream.read(bom) != -1) {
if (!(bom[0] == (byte) 0xEF && bom[1] == (byte) 0xBB && bom[2] == (byte) 0xBF)) {
pushbackInputStream.unread(bom);
}
}
return pushbackInputStream; }
那你就可以了
InputStream is=conn.getInputStream();
is = checkForUtf8BOMAndDiscardIfAny(is);
我沒有機會測試該方法，但它應該這樣做.另外，請參閱 字節順序標記搞砸了 Java 中的文件讀取.
I don't have a chance to test the method but it should do it. Also, please see Byte order mark screws up file reading in Java.
這篇關于XML 解析器返回意外的令牌錯誤和空指針異常的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！