Question

我使用Jaxb从我的XML文件中读取和写入。我想在我的XML中更新空间元素，但我不知道如何在我的代码中执行此操作，您可以使用任何正文我该怎么做我的更新方法

public boolean Update(Layer entity) {
  try {
  File file = new File(Test.PathXMl);
   //read from my xml
  JAXBContext jaxbContext = JAXBContext.newInstance(Project.class);
  Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
  Project project = (Project) jaxbUnmarshaller.unmarshal(file);
   // here update my XML new value but not special element
   Layer layer = new Layer();   
  layer.setLayerName(entity.getLayerName());
  layer.setOrder(entity.getOrder());
  layer.setVisible(entity.isVisible());
  project.getLayer().add(layer);
  //write in xml file 
  ObjectFactory objectFactory = new ObjectFactory();
  javax.xml.bind.Marshaller marshaller = jaxbContext.createMarshaller();
  marshaller.setProperty(marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
  marshaller.marshal(project, new FileOutputStream(Test.PathXMl));
  } catch (FileNotFoundException e) {
    e.printStackTrace();
  } catch (JAXBException e) {
    e.printStackTrace();
  }
     return false;
 }

我的XML文件：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Project xmlns="http://www.example.org/ProjectDataBase" name="name1">
    <Layer idLayer="2">
        <LayerName>a</LayerName>
        <Order>2</Order>
        <Visible>false</Visible>
    </Layer>
    <Layer idLayer="1">
        <LayerName>add</LayerName>
        <Order>1</Order>
        <Visible>true</Visible>
    </Layer>
</Project>

注意：例如，我需要更改LayerName中的值 - >＆gt; b但是只需IdLayer="2"（在我的代码中我无法选择我要更新的元素）请以任何方式做到这一点!!!!

Answer 1

一旦解组了XML，就应该执行以下检查

// unmarshal Project
for(Layer layer : project.getLayer()) {
    if (layer.getIdLayer().equals("2")) {
        layer.setLayerName("b");
    }
}
// marshal Project back to XML

我如何更新JAXB中的特殊元素？

1 个答案: