java - 从文件中提取多个 xml 标记之间的数据的最佳方法

Question

<小时/>

> <DOC>
> <Car> Zen </Car> 
> <Description> This is a bla bla model. which is a bla
> bla thisnf dsgs
> sdfsgssssssssssssssssssssssssssssssssssssssssssttttttttttttttwqqqqqqqqq
> dsgdsdsssssssssssegsegsdgsdgsdsssssssssssssssssssssttttttttttttt
> sdgssddddddddddddddddddddddddddddddddddddddddddddddsdddddddddwwww
> dgdssdddddddddddddddddddddddddddddsssssssssssssssssssssssswwwwwwwwwwww
> gdgdsssssssssssssssssssssssssssssssssssssssssssssssssseeeeeeeeeeeeee
> gddsssssssssssssssssssssssseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeqqqqqqqqqqq
> gsdsssssssssssssssssssssssssssssseqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
> dsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
> arrwerfkafjsdfsojfiosjfiosdfoisdoifjsdoifjiosdjfosdj</Description>
> <Year> 2015 </Year> <Color> Red </Color> 
> <Engine> afsdf </Engine>
> </DOC>

---更多标签----

> <DOC>
> <Car> Zen1 </Car> <Description> This is the second text tag which is a
> bla bla thisnf dsgs
> sdfsgssssssssssssssssssssssssssssssssssssssssssttttttttttttttwqqqqqqqqq
> dsgdsdsssssssssssegsegsdgsdgsdsssssssssssssssssssssttttttttttttt
> sdgssddddddddddddddddddddddddddddddddddddddddddddddsdddddddddwwww
> dgdssdddddddddddddddddddddddddddddsssssssssssssssssssssssswwwwwwwwwwww
> gdgdsssssssssssssssssssssssssssssssssssssssssssssssssseeeeeeeeeeeeee
> gddsssssssssssssssssssssssseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeqqqqqqqqqqq
> gsdsssssssssssssssssssssssssssssseqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
> dsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
> arrwerfkafjsdfsojfiosjfiosdfoisdoifjsdoifjiosdjfosdj</Description>
> <Year> 2015 </Year> <Color> Red </Color> <Engine> afsdf </Engine>
> </DOC>

---更多标签----

我有几个文件，每个文件中都有很多这样的标签。提取每个标签之间的数据的最佳方法是什么？这是我的方法

> for (File file : files) { 
> System.out.println(file.getName());   
> if
> (file.isFile()) {         
> try {
>       BufferedReader bufferReader = new BufferedReader(new FileReader(file));             >       String line; 
>       XContentBuilder builder = null;
>       StringBuffer sb = null; 
>       String descrption= null; 
>       String car =null;   
>       Boolean within_description = false; 
>           String Car= "";
>           while ((line = bufferReader.readLine()) != null) {
>               // System.out.println(line);
>               if (line.equals("<DOC>")) {
>                   builder = jsonBuilder();
>                   sb = new StringBuffer();
>                   continue;
>               } 
>               
>       
>               if (line.contains("<CAR>")) {
>                    
>                   String remove_front_space = line.replaceAll("<CAR>",
>                           "");
>                   car= remove_front_space .replaceAll("</CAR>",
>                           "").trim();
>                   builder = builder.startObject().field("CARR",
>                           car);
>                   continue;
>               }
>               if (line.equals("</DESCRIPTION>")) {
>                   within_description = false;
>                   continue;
>               }
>               if (within_description) {
>                   sb.append(line);
>                   continue;
>               }
>               if (line.equals("<DESCRIPTION>")) {
>                   within_description = true;
>                   continue;
>               }
>               if (line.equals("</DOC>")) {
>                   // JSONifying the string data
>                   text_toadd = sb.toString();
>                   builder = builder.field("text", text_toadd)
>                           .endObject();
>                   sb = null;

----Make database call and store CAR and DESCRIPTION information into Database.

>                 }     
>           bufferReader.close(); 
>           String json = builder.string(); 
>           System.out.println(json);
> 
>       } catch (IOException e) {           
>           e.printStackTrace();        
>       }
>   } }

任何建议都可以。提前致谢!

Answer 1

有一篇很棒的帖子here其中讨论了如何使用 DOM 解析器将 XML 文件提取到树中。需要记住的重要一点是，您的 XML 文件中必须有一个根元素。如果不这样做将导致以下 SAXParseException:

org.xml.sax.SAXParseException: The markup in the document following the root element must be well-formed.

如果您没有根元素，则此异常有点误导。发生的情况是解析器假设它命中的第一个标签是根元素。当它遇到该假定根元素的 close 之外的内容时，它会翻转并死亡。应该清楚的是，解析器失败是因为它试图构建一棵树，但如果没有根，它就会有悬空标签，无法附加到任何东西。