問題描述

我想解析以下 XML 文檔以解析其中的所有實體:

 <!DOCTYPE doc SYSTEM 'mydoc.dtd'><doc>&title;</doc>

我的 EntityResolver 應該從數(shù)據(jù)庫中獲取具有給定系統(tǒng) ID 的外部實體，然后進行解析，請參見下圖:

 私有靜態(tài)類 MyEntityResolver{public InputSource resolveEntity(String publicId, String systemId)拋出 SAXException、IOException{//此時systemId總是被絕對化為當前工作目錄，//即使 XML 文檔將其指定為相對的.//例如file:///H:/mydoc.dtd" 而不僅僅是mydoc.dtd"http://為什么???我怎樣才能防止這種情況???SgmlEntity 實體 = findEntityFromDatabase(systemId);InputSource is = new InputSource(new ByteArrayInputStream(entity.getContents()));is.setPublicId(publicId);is.setSystemId(systemId);回報是；}}

我嘗試使用 DOM (DocumentBuilder) 和 SAX (XMLReader)，將實體解析器設置為 MyEntityResolver(即 setEntityResolver(new MyEntityResolver()))，但 systemId在 MyEntityResolver#resolveEntity(String publicId, String systemId) 中總是被絕對化到當前工作目錄.

我也嘗試調(diào)用 setFeature("http://xml.org/sax/features/resolve-dtd-uris", false);，但沒有任何幫助.p>

那么我怎樣才能實現(xiàn)我想要的呢?

謝謝！

顯然還有一個接口叫EntityResolver2 是舊 EntityResolver.(談論令人困惑的名字！)

無論如何，我發(fā)現(xiàn) EntityResolver2 實現(xiàn)了我想要的，也就是說，它沒有對 systemId 進行任何更改，所以它始終是指定的在 XML 文檔中.

I want to parse the following XML document to resolve all entities in it:

 <!DOCTYPE doc SYSTEM 'mydoc.dtd'>
 <doc>&title;</doc>

My EntityResolver is supposed to fetch the external entity with the given system ID from the database and then do the resolution, see below for an illustration:

 private static class MyEntityResolver
 {
    public InputSource resolveEntity(String publicId, String systemId)
        throws SAXException, IOException
    {
        // At this point, systemId is always absolutized to the current working directory, 
        // even though the XML document specified it as relative.
        // E.g. "file:///H:/mydoc.dtd" instead of just "mydoc.dtd"
        // Why???  How can I prevent this???

        SgmlEntity entity = findEntityFromDatabase(systemId);
        InputSource is = new InputSource(new ByteArrayInputStream(entity.getContents()));
        is.setPublicId(publicId);
        is.setSystemId(systemId);
        return is;
    }
 }

I tried both using DOM (DocumentBuilder) and SAX (XMLReader), set the entity resolver to MyEntityResolver (i.e. setEntityResolver(new MyEntityResolver())), but systemId in MyEntityResolver#resolveEntity(String publicId, String systemId) is always being absolutized to the current working directory.

I also tried calling setFeature("http://xml.org/sax/features/resolve-dtd-uris", false);, but that didn't help anything.

So how can I achieve what I wanted?

Thanks!

Apparently, there is another interface called EntityResolver2 which is the extension of the old EntityResolver. (Talk about confusing names!)

Anyway, I found that EntityResolver2 achieved what I wanted, that is, it does not make any changes to the systemId, so it will always exactly be what was specified in the XML document.

這篇關(guān)于Java:如何防止 EntityResolver#resolveEntity(String publicId, String systemId) 中的“systemId"被絕對化到當前工作目錄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(wǎng)！