Unmarshal对象内的Java循环

Question

At this link: JAXB Unmarshalling XML string - Looping through all tags it was proposed a good solution. I'm trying to benefit from it but I am not able to have it working in my case.

Consider a XML like this:

<campaign value="field1">
  <name value="firstName"/>
  <type value="type"/>
  <record>
    <firstTime value="13"/>
    <secondTime value="14"/>
  </record>
</campaign>

And consider all the classes for Unmarshalling, created and working. campaign class, containing name, value, record[] etc.

JAXBContext c = JAXBContext.newInstance(Campaign.class);
Unmarshaller u = c.createUnmarshaller();
Campaign campaign = (Campaign) u.unmarshal(file);

I can extract the value of "name" and "type" but, because of the List<>, I am not able to go beyond this.

private String Name = null;
[...]
Name = campaign.getName().getValue();
System.out.println(Name);

How would you loop into <record> , and get all the values for firstTime and secondTime, knowing that there could be more <record> in other XML file?

EDIT: Campaign Class

@XmlRootElement(name = "Campaign")
@XmlType(name = "Campaign", propOrder = {
    "Name",
    "Type",
    "Record" })
public class Campaign {
    @XmlElement(required = true)
    protected Name Name;

    @XmlElement(required = true)
    protected Type Type;

    @XmlElement(required = true)
    protected List<Record> Record= new ArrayList<Record>();


    public Name getName () {return Name;}
    public void setName (Name value) {this.Name= value;}

    public Type getType () {return Type;}
    public void setType (Type value) {this.Type = value;}

    public void setRecord(Recordvalue) {this.Record.add(value);}
}

Record Class

@XmlRootElement(name = "Record")
@XmlType(name = "Record", propOrder = {
    "firstTime",
    "secondTime" })
public class Record{
    @XmlElement(required = true)
    protected firstTime firstTime;

    @XmlElement(required = true)
    protected secondTime secondTime;


    public Name getFirstTime () {return firstTime;}
    public void setFirstTime (firstTime value) {this.firstTime= value;}

    public Name getSecondTime () {return secondTime;}
    public void setSecondTime (secondTime value) {this.secondTime= value;}
}

The program is much more big, but it just keeps repeating.. I need to extract everything in order to upload to a DB later. But now, I only need to print them on screen and knowing that I have all the values I'd need.

Yes I had a look at that link too, I don't know why I just can't concentrate on how to continue, seems that the worst part was easier for me!

Thanks

EDIT 3 : I forgot to paste the methods for set and get.

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "Type")
public class Type {

    @XmlAttribute
    protected String value;

    public String getValue() {return value;}
    public void setValue(String value) {this.value = value;}
}

It is the same for all, I simply pasted Type here.

EDIT 4: The resolution I was finally able to find the solution, which is not the one proposed and marked as correct. Although it helped me creating the getRecord() getter.

Without changing my code, but adding to the record.class:

public List<Record> getRecord() { return this.Record; }

and to the main class:

for (int i=1; i<=campaign.getRecord().size(); i++)   {                System.out.println(campaign.getRecord().get(i-1).getFirstTime().getValue());
System.out.println(campaign.getRecord().get(i-1).getSecondTime().getValue());
}

I am able to print "13" and "14", more in general, I am able to print anything inside record and if record would have another List inside, one more:

for (int j=1; j<= campaign.getRecord().get(i-1).getANewListInsideRecord().size(); j++) {
System.out.println(campaign.getRecord().get(i-1).getANewListInsideRecord().get(j-1).getAObject().getValue());
}

will do the the job.

-1 because it starts from 0.

Answer 1

I'm still unsure about what your problem is. Tell me if my answer is not what you're looking for.

You have a few changes to make :

@XmlRootElement(name = "campaign")
@XmlType(name = "campaign", propOrder = {
    "name",
    "type",
    "record" })
public class Campaign {
    @XmlElement(required = true)
    protected Name name;

    @XmlElement(required = true)
    protected Type type;

    @XmlElement(required = true)
    protected List<Record> record;


    public Name getName () {return name;}
    public void setName (Name value) {this.name= value;}

    public Type getType () {return type;}
    public void setType (Type value) {this.type = value;}

    //Initialise your record list inside the getter instead of in member declaration
    public List<Record> getRecord() {
        if(this.record == null) record = new ArrayList<>();
        return this.record;
    }

    //Do not use a setter as an add method for the list
    public void setRecord(List<Record> value) {this.record = value;}

    //If you need to add record inside your list, do not use a setter, define an add method or access the list with the getter.
    public void addRecord(Record value) {this.record.add(value);}
}

I'll go under the assumption that you have defined proper toString() method for all of the classes used in the Campaign.

For exemple, the Record class string may go like :

@Override
public String toString(){
    return " First value : + "this.firstTime.getValue() + " Second value : " +this.secondTime.getValue();
}

Now to display everything :

List<File> files = new ArrayList<>();

//Add all XML Files containing a campaign root element into the files list
JAXBContext c = JAXBContext.newInstance(Campaign.class);
Unmarshaller u = c.createUnmarshaller();

//Declare list to store all of your camapaign object
List<Campaign> campaigns = new ArrayList<>();

for(File f : files)
{
    campaigns.add(u.unmarshall(f));
}

//display all campaigns
for(Campaign camp : campaigns){
    System.out.println(camp.getName());
    System.out.println(camp.getType());

    //Display all records
    for(Record rec : camp.getRecord()){
        System.out.println(rec);
    }
}

You can of course change the System.out.println() lines to whatever code you want.