問(wèn)題描述

我正在制作一個(gè)讀取 XML Internet 的 Android 應(yīng)用程序.此應(yīng)用程序使用 SAX 來(lái)解析 XML.這是我的解析部分代碼:

I'm making an Android application that reads an XML Internet. This application uses SAX to parse XML. This is my code for the part of parsing:

public LectorSAX(String url){
    try{
        SAXParserFactory spf=SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();
        DefaultHandler lxmlr=new LibraryXMLReader() ;
        sp.parse(url, lxmlr);

        nodo=((LibraryXMLReader)lxmlr).getNodoActual();

    }catch(ParserConfigurationException e){ 
        System.err.println("Error de parseo en LectorSAX.java: "+e);
    }catch(SAXException e){
        System.err.println("Error de sax LectorSAX.java: " + e);
    } catch (IOException e){
        System.err.println("Error de  io LectorSAX.java: " + e);
    }
}

問(wèn)題是發(fā)生了 SAXException.異常信息如下:

The problem is that SAXException occurs. The exception message is as follows:

org.apache.harmony.xml.ExpatParser$ParseException:在第 4 行，第 4 列42:格式不正確(無(wú)效令牌)

org.apache.harmony.xml.ExpatParser$ParseException: At line 4, column 42: not well-formed (invalid token)

但是，如果我將相同的代碼放入普通的 Java SE 應(yīng)用程序中，則不會(huì)發(fā)生此異常并且一切正常.

However, if I put the same code in a normal Java SE application, this exception does not occur and everything works fine.

為什么相同的代碼在 Java SE 應(yīng)用程序中運(yùn)行良好，而不是在 Android 中運(yùn)行?另一方面，如何解決這個(gè)問(wèn)題?

Why the same code works fine in a Java SE application, not an Android?. On the other hand, How to solve the problem?.

感謝您的幫助.

您好.

推薦答案

這可能是字符編碼問(wèn)題.
如您所見(jiàn)，無(wú)效令牌錯(cuò)誤指向第 4 行.
在這一行中，您可以找到一個(gè)銳號(hào) (Meteorología) 和一個(gè)波浪號(hào) (Espa?a).XML 標(biāo)頭顯示 ISO-8859-15 編碼值.由于它不如 UTF 或 ISO-8859-1 編碼常見(jiàn)，因此當(dāng) SAXParser 連接并嘗試使用系統(tǒng)默認(rèn)字符集將字節(jié)內(nèi)容轉(zhuǎn)換為字符時(shí)，這可能會(huì)導(dǎo)致錯(cuò)誤.

This could be a character encoding problem.
As you can see, the invalid token error points to the line #4.
In this line, you can find an acute (Meteorología) and a tilde (Espa?a). The XML header shows a ISO-8859-15 encoding value. As it's less common than UTFs or ISO-8859-1 encodings, this could result in a error when the SAXParser connects and try to convert the byte content into chars using your system default charset.

然后，您需要告訴 SAXParser 使用哪個(gè)字符集.一種方法是傳遞 InputSource，而不是 URL，到 parse 方法.舉個(gè)例子:

Then, you'll need to tell the SAXParser which charset to use. A way to do so, is to pass an InputSource, instead of the URL, to the parse method. As an example:

SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();

InputSource is = new InputSource(url);
is.setEncoding("ISO-8859-15");

DefaultHandler lxmlr=new LibraryXMLReader() ;
sp.parse(is, lxmlr);

Android VM 似乎不支持這種編碼，拋出 org.apache.harmony.xml.ExpatParser$ParseException: At line 1, column 0: unknown encoding 異常.
作為 ISO-8859-15，它主要與 ISO-8859-1 兼容，除了一些特定字符(如您所見(jiàn) here)，解決方法是在 setEncoding 方法中將 ISO-8859-15 值更改為 ISO-8859-1，強(qiáng)制解析器使用不同但兼容的字符集編碼:

It seems that Android VM does not support this encoding, throwing a org.apache.harmony.xml.ExpatParser$ParseException: At line 1, column 0: unknown encoding exception.
As ISO-8859-15 it's mainly compatible with ISO-8859-1, except some specific characters (as you can see here), a workaround is changing the ISO-8859-15 value to ISO-8859-1 at the setEncoding method, forcing the parser to use a different but compatible charset encoding:

is.setEncoding("ISO-8859-1");

看起來(lái)，由于 Android 不支持聲明的字符集，它使用其默認(rèn) (UTF-8)，因此解析器無(wú)法使用 XML 聲明來(lái)選擇適當(dāng)?shù)木幋a.

As it seems, as Android doesn't support the declared charset, it uses its default (UTF-8) and hence the parser can't use the XML declaration to choose the apropiate encoding.

這篇關(guān)于Sax - ExpatParser$ParseException的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！