JAXB - 解组XML异常 [英] JAXB - unmarshal XML exception

问题描述

我试过读一个大的xml文件（类似于500MB）。
首先，我使用xjc和我的XML的XSD文件。所有类都按预期生成。
尝试读取文件我遇到了这个错误：javax.xml.bind.UnmarshalException：意外元素。

I've tried to read a big xml file (something like 500MB). First of all, I used xjc with the XSD file of my XML. All classes were generated as expected. Trying to read the file I've got this error: javax.xml.bind.UnmarshalException: unexpected element.

这是我的代码：

（...）

JAXBContext context = JAXBContext.newInstance("br.com.mypackage");
Unmarshaller unmarshaller = context.createUnmarshaller();
File f = new File("src/files/MyHuge.CNX");
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
InputStream in = new FileInputStream(f);
XMLEventReader eventReader = inputFactory.createXMLEventReader(in);
Person p = null;
int count = 0;
while (eventReader.hasNext()) {
   XMLEvent event = eventReader.nextEvent();
   if (event.isStartElement()) {
      StartElement startElement = event.asStartElement();
      if (startElement.getName().getLocalPart() == ("person")) {
         p = (Person) unmarshaller.unmarshal(eventReader);
      }
   }
}

问题出在unmarshal上操作。

The problem is in the unmarshal operation.

Caused by: javax.xml.bind.UnmarshalException: unexpected element (uri:"", local:"identification"). Expected elements are <{}messageAll>

我使用此链接作为示例来制作我自己的代码：JAXB - unmarshal OutOfMemory：Java堆空间

I used this link as example to make my own code: JAXB - unmarshal OutOfMemory: Java Heap Space

有人有这样做的线索？我现在想要的只是读取一个巨大的XML文件，而不用解组XML的外部对象（java堆空间问题），而无需通过标记读取标记获取相应的值，一个缓慢的猴子代码（不是行星的崛起的猴子）猿猴）。 ：P

Someone has a clue to do it? All that I want now is to read a huge XML file without unmarshal the external object of XML (java heap space problem) and without reading tag by tag getting the respective value, a slow and monkey code (not the monkeys of Rise of the Planet of the Apes). :P

非常感谢。

推荐答案

我用以下代码解决了问题：

I solved the problem with this code bellow:

public List<Person> testeUnmarshal() {
  List<Person> people = new ArrayList<Person>();
  Person p = null;
  try {
    JAXBContext context = JAXBContext.newInstance(Person.class);
    Unmarshaller unmarshaller = context.createUnmarshaller();
    File f = new File(FILE_PATH);
    XMLInputFactory inputFactory = XMLInputFactory.newInstance();
    XMLEventReader eventReader = inputFactory.createXMLEventReader(new FileInputStream(f));
    while (eventReader.hasNext()) {
      XMLEvent event = eventReader.peek();
      if (event.isStartElement()) {
        StartElement start = event.asStartElement();
    if (start.getName().getLocalPart() == "person")) {
          JAXBElement<Person> jax_b = unmarshaller.unmarshal(eventReader, Person.class);
      p = jax_b.getValue();
    }
      }
      eventReader.next();
    }
  } catch (Exception e) {
  }
  return persons;
}

我可以使用循环内的计数来控制内存中的对象数量（对于1000人在数据库中提交。）

I can control the amount of objects in memory using counts inside a loop (for 1000 Persons commit in database).

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