"Class has two properties of the same name" error when converting an XML file into a Java object

Question

I have an XML file like below, and I want to convert it into a Java object.

<P1>
    <CTS>
        Hello
    </CTS>
    <CTS>
        World
    </CTS>
<P1>

So I created the following Java classes with their properties.

P1 class

@XmlRootElement
public class P1 {
    @XmlElement(name = "CTS")
    List<CTS> cts;
}

CTS class

public class CTS {
    String ct;
}

Test Class

File file = new File("D:\\ContentTemp.xml");
            JAXBContext jaxbContext = JAXBContext.newInstance(P1.class);
     
            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            P1 p = (P1) jaxbUnmarshaller.unmarshal(file);

But I am getting the following error:

com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException:
2 counts of IllegalAnnotationExceptions
Class has two properties of the same name "cts"

You need to put package-info.java in your generated jaxb package. — Festus Tamakloe, Dec 21 '12 at 09:57
@Festus I am not getting your point. Can you please explain. — Thinker, Dec 21 '12 at 09:58
you may want to use Hello World better to wrap group of same elements in a wrapper. — Senthil Kumar, Dec 21 '12 at 10:02
Normally you have to create a xml schemata that generates automatically the java objects for you. until you want to do it manually you have to create package-info.java by yourselves — Festus Tamakloe, Dec 21 '12 at 10:03
it would but you declared P1 as XMLRootELement. I would have done like P1 as XMLRootElement, CTSWrapper as XMLELementWrapper, CTS as XMLElement. This way i have never faced issues with marshalling/unmarshalling and works good with json (jackson) too. — Senthil Kumar, Dec 21 '12 at 10:28

score 4 · Accepted Answer · edited Feb 10 '23 at 20:53

com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException:
2 counts of IllegalAnnotationExceptions
Class has two properties of the same name "cts"

By default a JAXB (JSR-222) implementation creates mappings based on properties and annotated fields. When you annotate a field for which there is also a property it will cause this error.

You have two options:

Use @XmlAccessorType(XmlAccessType.FIELD)

You could annotate the field you need to specify @XmlAccessorType(XmlAccessType.FIELD) on the class.
```
@XmlRootElement(name="P1)
@XmlAccessorType(XmlAccessType.FIELD)
public class P1 {

    @XmlElement(name = "CTS")
    List<CTS> cts;

}
```

Option #2 - Annotate the Property (get method)**

Alternatively you could annotate the get method.

@XmlRootElement(name="P1)
public class P1 {

    List<CTS> cts;

    @XmlElement(name = "CTS")
    public List<CTS> getCts() {
        return cts;
    }

}

For More Information

http://blog.bdoughan.com/2011/06/using-jaxbs-xmlaccessortype-to.html

FULL EXAMPLE

CTS

You can use the @XmlValue annotation to map to Java class to a complex type with simple content.

@XmlAccessorType(XmlAccessType.FIELD)
public class CTS {

    @XmlValue
    String ct;

}

P1

import java.util.List;
import javax.xml.bind.annotation.*;

@XmlRootElement(name="P1")
@XmlAccessorType(XmlAccessType.FIELD)
public class P1 {

    @XmlElement(name = "CTS")
    List<CTS> cts;

}

Demo

import java.io.File;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(P1.class);
        
        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum13987708/input.xml");
        P1 p1 = (P1) unmarshaller.unmarshal(xml);
        
        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(p1, System.out);
    }
    
}

input.xml/Output

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<P1>
    <CTS>
        Hello
    </CTS>
    <CTS>
        World
    </CTS>
</P1>

For More Information

http://blog.bdoughan.com/2011/06/jaxb-and-complex-types-with-simple.html

score 0 · Answer 2 · answered Dec 21 '12 at 09:55

0

Two issues I can see:

1) You need to use P1.class in your JAXBContext. You haven't said what the Presentation class is, but if your root element is P1, that's what you need in the context:

JAXBContext jaxbContext = JAXBContext.newInstance(P1.class);

2) You need to specify the name of the root xml element:

@XmlRootElement(name="P1")
public class P1 {
...

answered Dec 21 '12 at 09:55

dogbane

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this is right . I have changed the variable name .forgot to change it in test class. – Thinker Dec 21 '12 at 09:57
I can't reproduce your error because you haven't posted all the code. Do you have a method called `cts()` as well? If so, try renaming it to something else. – dogbane Dec 21 '12 at 10:00
no.this is whole my code. There is only getter and setters other than this code. The error showing is because it has two cts in xml file – Thinker Dec 21 '12 at 10:03
no, I have run the code you posted and it works for me. According to the error, you have two properties called `cts` in the class. It doesn't have anything to do with your xml. – dogbane Dec 21 '12 at 10:05
code run without error in your system? – Thinker Dec 21 '12 at 10:07
yes, I do not get any errors. Have you tried running the code you posted in the question? – dogbane Dec 21 '12 at 10:09
Yes. It is not working. Is there is any jar neeeded. Let me give this code to my friend and see it works. – Thinker Dec 21 '12 at 10:09
why do you have `@XmlElement(name = "CT")` in the CTS class? What is CT? – dogbane Dec 21 '12 at 10:13

score 0 · Answer 3 · answered Dec 21 '12 at 10:11

Your XML looks like this:

<P1>
  <CTS>
    Hello
  </CTS>
  <CTS>
    World
  </CTS>
</P1>

But considering your mapping it should look like:

<p1>
  <CTS>
    <CT>
    Hello
    </CT>
  </CTS>
  <CTS>
    <CT>
    World
    </CT>
  </CTS>
</p1>

In order to change root element from p1 to P1 use attribute name from @XmlRootElement.

If you want to parse the first version of XML you posted, change your P1 class like this:

@XmlRootElement(name="P1")
public class P1 {
    @XmlElement(name = "CTS")
    List<String> cts;
 }

FYI - You can map the object model to the XML given by @Thinker by leveraging the `@XmlValue` annotation: http://stackoverflow.com/a/13988362/383861 — bdoughan, Dec 21 '12 at 10:53

Senthil Kumar · Answer 4 · 2012-12-21T10:43:10.280

You could try the following,

If you could, make xml as of the following structure.

<P1>
    <CTSList>
       <CTS value="Hello"/>
       <CTS value="World"/>
    </CTSList>
<P1>

And use,

@XMLRootElement(name="P1")
public class P1 {
  List CTSList;

  @XMLElementWrapper(name="CTSList")
  @XMLELement(name="CTS")
  public void setCTSList(List<CTS> ctsList) {
     this.CTSList = ctsList;
  }

  public List<CTS> getCTSList() {
    return this.CTSList;
  }
}

@XMLRootElement(name="CTS")
public class CTS {
   String cts;

   @XMLAttribute(name = "value")
   public String getCts() {
     return this.cts;
   }

   public void set setCts(String cts) {
     this.cts = cts;
   }
}

FYI - You can map the object model to the XML given by @Thinker by leveraging the `@XmlValue` annotation: http://stackoverflow.com/a/13988362/383861 — bdoughan, Dec 21 '12 at 11:17

"Class has two properties of the same name" error when converting an XML file into a Java object

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