iPhone NSXMLParser（错误9）

Question

我尝试在我的iPhone SDK 4中进行解析。 http://de.news.search.yahoo.com/news/rss?p=iphone&ei=UTF-8&fl=0&x=wrt 其中有一些德语umlauts。

<description><![CDATA[Mehr als die Hälfte der Belegschaft des weltweit größten]]></description>

根据我在另一个论坛上的阅读，只要它们被包含在CDATA中，就应该没问题。但是一旦解析器发现了"描述"元素，它就会中断：

error parsing XML: Unable to download story feed from web site (Error code 9 ) http://de.news.search.yahoo.com/news/rss?p=iphone&ei=UTF-8&fl=0&x=wrt

英译中：

英文的反馈很好！？所以这与这个特殊字符有关，但我该怎么办呢？

问候 克里斯

仅供理解...这是我的整个解析器

- (void)parseXMLFileAtURL:(NSString *)URL { 
    aktuelleUrl = URL;
    stories = [[NSMutableArray alloc] init];
    NSURL *xmlURL = [NSURL URLWithString:aktuelleUrl];

// here, for some reason you have to use NSClassFromString when trying to alloc NSXMLParser, otherwise you will get an object not found error
// this may be necessary only for the toolchain
rssParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL];

// Set self as the delegate of the parser so that it will receive the parser delegate methods callbacks.
[rssParser setDelegate:self];

// Depending on the XML document you're parsing, you may want to enable these features of NSXMLParser.
[rssParser setShouldProcessNamespaces:NO];
[rssParser setShouldReportNamespacePrefixes:NO];
[rssParser setShouldResolveExternalEntities:NO];    
[rssParser parse];

}
- (void)parserDidStartDocument:(NSXMLParser *)parser{   
//NSLog(@"found file and started parsing");

}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError {
NSString * errorString = [NSString stringWithFormat:@"Unable to download story feed from web site (Error code %i ) %@", [parseError code], aktuelleUrl];
NSLog(@"error parsing XML: %@", errorString);

}



- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{            
NSLog(@"found this element: %@", elementName);
currentElement = [elementName copy];

if ([elementName isEqualToString:@"channel"]) {
    channel1item2 = 1;
    // clear out our story item caches...
    //  item = [[NSMutableDictionary alloc] init];
    currentTitle = [[NSMutableString alloc] init];
    //  currentDate = [[NSMutableString alloc] init];
    currentSummary = [[NSMutableString alloc] init];
    currentLink = [[NSMutableString alloc] init];
}

if ([elementName isEqualToString:@"item"]) {
    channel1item2 = 2;
    // clear out our story item caches...
    item = [[NSMutableDictionary alloc] init];
    currentTitle = [[NSMutableString alloc] init];
    currentDate = [[NSMutableString alloc] init];
    currentSummary = [[NSMutableString alloc] init];
    currentLink = [[NSMutableString alloc] init];
    currentEncoded = [[NSMutableString alloc] init];

    }   
    }
     - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{     
//NSLog(@"ended element: %@ c1i2: %i", elementName, channel1item2);

if (channel1item2 == 1) {
    if (![currentTitle isEqualToString:@""]) { aCurrentTitle = currentTitle;  }
    if (![currentLink isEqualToString:@""])  { aCurrentLink = currentLink; }
    if (![currentSummary isEqualToString:@""])  {aCurrentSummary = currentSummary; }
}
else if ([elementName isEqualToString:@"item"]) {
    [item setObject:currentTitle forKey:@"title"];
    [item setObject:currentLink forKey:@"link"];
    [item setObject:currentSummary forKey:@"summary"];
    [item setObject:currentDate forKey:@"date"];
    [item setObject:currentEncoded forKey:@"content:encoded"];      
    [stories addObject:[item copy]];
}   
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
//NSLog(@"found characters: %@", string);
// save the characters for the current item...
if ([currentElement isEqualToString:@"title"]) {
    [currentTitle appendString:string];
} else if ([currentElement isEqualToString:@"link"]) {
    [currentLink appendString:string];
    //NSLog(@"parselink '%@'",string);
} else if ([currentElement isEqualToString:@"description"]) {
    [currentSummary appendString:string];
} else if ([currentElement isEqualToString:@"pubDate"]) {
    [currentDate appendString:string];
} else if ([currentElement isEqualToString:@"content:encoded"]) {
    [currentEncoded appendString:string];
}
else if ([currentElement isEqualToString:@"media:content"]) {
    //NSLog(@"mediacontent %@",string);
}   
}
- (void)parserDidEndDocument:(NSXMLParser *)parser {

// NSLog(@"all done!");
//NSLog(@"stories array has %d items", [stories count]);
}

- christian Muller

---

如果您只解析字符串__@“<openTag> <! [CDATA [ß]]> </ openTag>__，是否仍然会出现错误？如果没有，那么问题就不是因为umlaut引起的。 - deanWombourne

我应该在哪里更改什么？ :) 我还在其他论坛上看到，这通常发生在有umlaut的情况下，但没有真正的解决方案。为了理解，我将我的整个解析器放在了我的问题中。 - christian Muller

Answer 1

也许可以研究一下-stringWithContentsOfURL:usedEncoding:error:方法来下载XML：

NSError *error = nil;
NSStringEncoding encoding;
NSString *xmlFeedStr = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://de.news.search.yahoo.com/news/rss?p=iphone&ei=UTF-8&fl=0&x=wrt"] usedEncoding:&encoding error:&error];
NSXMLParser *rssParser = [[NSXMLParser alloc] initWithData:[xmlFeedStr dataUsingEncoding:encoding allowLossyConversion:YES]];
...
[rssParser release];

- Alex Reynolds

---

谢谢，我尝试了一下，我想我朝着正确的方向前进了。但是仍然出现错误代码5..只有在那个URL上。看起来这个人已经为另一个解析器解决了这个问题，只是我不知道如何在我的代码中实现： http://petersteinberger.com/2010/06/use-tturlxmlresponse-with-server-that-send-you-the-wrong-encoding/ - christian Muller

Answer 2

来自文档:

NSXMLParserInvalidCharacterError = 9

也许这个文档并没有真正采用UTF-8编码？

- Alex Reynolds

---

问题是，该文档编码为utf-8，但雅虎服务器响应ISO-8859-1。您可以通过http://beta.feedvalidator.org查看。 - christian Muller

Answer 3

现在我用不同的方法解决了它。为我的需求编写了自己的简单XML解析器，并使用在某个论坛上找到的以下例程对XML字符串进行编码。同时，我将上面的答案标记为“已接受”，因为它引导我走向了正确的方向。

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)s {
    [resultString appendString:s];
}

- (NSString*)convertEntiesInString:(NSString*)s {
    resultString = [[NSMutableString alloc] init];

    if(s == nil) {
        //NSLog(@"ERROR : Parameter string is nil");
    }
    NSString* xmlStr = [NSString stringWithFormat:@"<d>%@</d>", s];
    NSData *data = [xmlStr dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    NSXMLParser* xmlParse = [[NSXMLParser alloc] initWithData:data];
    [xmlParse setDelegate:self];
    [xmlParse parse];
    NSString* returnStr = [[NSString alloc] initWithFormat:@"%@",resultString];

    return returnStr;
}


objectsResultStr = [self convertEntiesInString:orgString]];             

- christian Muller