XmlBeans在讀/寫過程中的源定位器

Question

我有從XSD生成的XmlBeans類。我想跟蹤持續對象的行號。這可能嗎？我不關心這些信息是在解析（xml→beans）期間還是在prettyprinting（beans→xml）期間存儲的，因爲我在應用程序流中將它們保持同步。

如果可能，我想開始和結束行/列號。

我不在乎是否必須使用某種非標準hack才能訪問定位器數據。

如果還有另一個Java XML框架可以從XSD文件和支持定位器數據生成類，那麼我願意切換。

Answer 1

只需使用XmlOptions#setLoadLineNumbers()，例如：

MyDocument.Factory.parse(xmlFile, new XmlOptions().setLoadLineNubmers()); 

然後從XML存儲檢索行號，找到最近的XmlLineNumber書籤。

import org.apache.xmlbeans.*; 

public class linenumber 
{ 
    public static void main(String[] args) throws XmlException 
    { 
     XmlOptions options = new XmlOptions().setLoadLineNumbers(); 
     XmlObject xobj = XmlObject.Factory.parse("<a>\n<b>test</b>\n<c>test</c>\n</a>", options); 

     // let's get the line number for the '<c>' xml object 
     XmlObject cobj = xobj.selectPath(".//c")[0]; 
     System.out.println(cobj.xmlText()); 

     XmlCursor c = null; 
     try 
     { 
      c = cobj.newCursor(); 

      // search for XmlLineNumber bookmark 
      XmlLineNumber ln = 
       (XmlLineNumber) c.getBookmark(XmlLineNumber.class); 

      if (ln == null) 
       ln = (XmlLineNumber) c.toPrevBookmark(XmlLineNumber.class); 

      if (ln != null) 
      { 
       int line = ln.getLine(); 
       int column = ln.getColumn(); 
       int offset = ln.getOffset(); 

       System.out.println("line=" + line + ", col=" + column + ", offset=" + offset); 
      } 
     } 
     finally 
     { 
      if (c != null) c.dispose(); 
     } 
    } 
} 

Answer 2

備註：我是EclipseLink JAXB (MOXy)的領導者和JAXB (JSR-222)專家組的成員。

如果有另一個Java XML框架，可以從 生成類XSD文件，並支持定位數據，那麼我願意切換。

JAXB可以從XML模式生成類，下面介紹幾種獲取位置信息的方法。對於JAXB和XMLBeans的的比較看：

• http://blog.bdoughan.com/2012/01/how-does-jaxb-compare-to-xmlbeans.html

選項1 - StAX的和的Unmarshaller.Listener

演示

package forum10241929; 

import java.io.File; 
import javax.xml.bind.*; 
import javax.xml.stream.*; 
import javax.xml.transform.stream.StreamSource; 

public class Demo { 

    public static void main(String[] args) throws Exception { 
     JAXBContext jc = JAXBContext.newInstance(Customer.class); 

     XMLInputFactory xif = XMLInputFactory.newFactory(); 
     XMLStreamReader xsr = xif.createXMLStreamReader(new StreamSource(new File("src/forum10241929/input.xml"))); 

     Unmarshaller unmarshaller = jc.createUnmarshaller(); 
     unmarshaller.setListener(new LocationListener(xsr)); 
     Customer customer = (Customer) unmarshaller.unmarshal(xsr); 
    } 

    private static class LocationListener extends Unmarshaller.Listener { 

     private XMLStreamReader xsr; 

     public LocationListener(XMLStreamReader xsr) { 
      this.xsr = xsr; 
     } 

     @Override 
     public void afterUnmarshal(Object target, Object parent) { 
      log("End", target); 
     } 

     @Override 
     public void beforeUnmarshal(Object target, Object parent) { 
      log("Start", target); 
     } 

     private void log(String event, Object target) { 
      System.out.print(event); 
      System.out.print(" "); 
      System.out.print(target); 
      System.out.print(" ["); 
      Location location = xsr.getLocation(); 
      System.out.print(location.getLineNumber()); 
      System.out.print(","); 
      System.out.print(location.getColumnNumber()); 
      System.out.println("]"); 
     } 

    } 

} 

input.xml中

<?xml version="1.0" encoding="UTF-8"?> 
<customer> 
    <name>Jane Doe</name> 
    <address> 
     <street>1 A Street</street> 
    </address> 
</customer> 

輸出

Start forum10241929.Customer@144aa0ce [2,11] 
Start forum10241929.Address@19e3cd51 [4,14] 
End forum10241929.Address@19e3cd51 [6,15] 
End forum10241929.Customer@144aa0ce [7,12] 

顧客

package forum10241929; 

import javax.xml.bind.annotation.XmlRootElement; 

@XmlRootElement 
public class Customer { 

    private String name; 
    private Address address; 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public Address getAddress() { 
     return address; 
    } 

    public void setAddress(Address address) { 
     this.address = address; 
    } 

} 

地址

package forum10241929; 

public class Address { 

    private String street; 

    public String getStreet() { 
     return street; 
    } 

    public void setStreet(String street) { 
     this.street = street; 
    } 

} 

選項＃2 - @XmlLocation

有是受兩者的EclipseLink JAXB（MOXY）支撐的JAXB延伸和參考實現稱爲@XmlLocation（下面是一個使用MOXy的示例）。這隻會捕獲開始位置。

package forum10241929; 

import javax.xml.bind.annotation.XmlRootElement; 
import org.eclipse.persistence.oxm.annotations.XmlLocation; 
import org.xml.sax.Locator; 

@XmlRootElement 
public class Customer { 

    private String name; 
    private Address address; 

    @XmlLocation 
    private Locator location; 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public Address getAddress() { 
     return address; 
    } 

    public void setAddress(Address address) { 
     this.address = address; 
    } 

}