Java / Android：将xml转换为可循环对象的最简单方法？ （地图？）

Question

I have a string containing XML content with the following structure. My question is, how do i easily convert it to an object of some sort, and then loop through all of the items within ?

Are there any easy to use libraries that does this? If so, examples would be great. I recently got in to Java developing and i'm still learning.

I just read about XStream ( http://x-stream.github.io/tutorial.html ), and it seems very promising. I just don't know how to properly apply it.

<requests>
    <0>
        <id>1</id>
        <key>sms_number</key>
        <value>0709601159</value>
    </0>
    <1>
        <id>1</id>
        <key>sms_text</key>
        <value>This is a text message, blablabla.</value>
    </1>
</requests>

Any suggestions, ideas or examples are very appreciated.

Answer 1

Create a class that defines what the object is:

public class Term implements Serializable {


private static final long serialVersionUID = 1L;
private String word;
private String abbr1;
private String abbr2;
private String definition;
private String formula;

public String getWord() {
    return word;
}
public void setWord(String word) {
    this.word = word;
}
public String getAbbr1() {
    return abbr1;
}
public void setAbbr1(String abbr1) {
    this.abbr1 = abbr1;
}
public String getAbbr2() {
    return abbr2;
}
public void setAbbr2(String abbr2) {
    this.abbr2 = abbr2;
}
public String getDefinition() {
    return definition;
}
public void setDefinition(String definition) {
    this.definition = definition;
}
public String getFormula() {
    return formula;
}
public void setFormula(String formula) {
    this.formula = formula;
}

}

Then use an XML parser to parse through your XML:

public ArrayList<Term> getTerms(){
    ArrayList<Term> termsList = new ArrayList<Term>();

    //create array lists for the four attributes of each term
    ArrayList<String> word = new ArrayList<String>();
    ArrayList<String> abbr1 = new ArrayList<String>();
    ArrayList<String> abbr2 = new ArrayList<String>();
    ArrayList<String> definition = new ArrayList<String>();
    ArrayList<String> formula = new ArrayList<String>();

    //Strings for each of the attributes
    String currentWord = null;
    String currentAbbr1 = null;
    String currentAbbr2 = null;
    String currentDefinition = null;
    String currentFormula = null;



    //try to parse the XML into the four array lists
    try{

        //get the xml document and put it into a reader
        XmlPullParser parser = getResources().getXml(R.xml.terminology);

        //set the eventType and the boolean to test if finished.
        int eventType = parser.getEventType();
        boolean done = false;

        /*
         * while statement that will read through the xml document and includes
         * a switch case block that will go through the tags and put the attributes
         * into the appropriate array lists
         */
        while (eventType !=XmlPullParser.END_DOCUMENT && !done){
            String name = null;
            switch (eventType){
            case XmlPullParser.START_DOCUMENT:
                break;
            case XmlPullParser.START_TAG:
                name = parser.getName();
                if (name.equalsIgnoreCase("terminology")){

                }else if (word != null && abbr1 != null && abbr2 != null && definition != null && formula != null){
                    if (name.equalsIgnoreCase("term")){

                    }else if (name.equalsIgnoreCase("word")){
                        currentWord = new String(parser.getAttributeValue(0));
                    }else if (name.equalsIgnoreCase("abbr1")){
                        currentAbbr1 = new String(parser.getAttributeValue(0));
                    }else if (name.equalsIgnoreCase("abbr2")){
                        currentAbbr2 = new String(parser.getAttributeValue(0));
                    }else if (name.equalsIgnoreCase("definition")){
                        currentDefinition = new String(parser.getAttributeValue(0));
                    }else if (name.equalsIgnoreCase("formula")){
                        currentFormula = new String(parser.getAttributeValue(0));
                    }
                }
                break;
            case XmlPullParser.END_TAG:
                name = parser.getName();
                if (name.equalsIgnoreCase("formula") && currentFormula != null){
                    formula.add(currentFormula);
                }else if (name.equalsIgnoreCase("definition") && currentDefinition != null){
                    definition.add(currentDefinition);
                }else if (name.equalsIgnoreCase("abbr2") && currentAbbr2 != null){
                    abbr2.add(currentAbbr2);
                }else if (name.equalsIgnoreCase("abbr1") && currentAbbr1 != null){
                    abbr1.add(currentAbbr1);
                }else if (name.equalsIgnoreCase("word") && currentWord != null){
                    word.add(currentWord);
                }else if (name.equalsIgnoreCase("term")){
                }else if (name.equalsIgnoreCase("terminology")){
                    done = true;
                }
                break;  
            }
            eventType = parser.next();
        }



    }
    catch (FileNotFoundException e){

    }
    catch (IOException e){

    }
    catch (Exception e){

    }

    for (int i=0; i < word.size(); i++){
        Term term = new Term();
        term.setWord(word.get(i));
        term.setAbbr1(abbr1.get(i));
        term.setAbbr2(abbr2.get(i));
        term.setDefinition(definition.get(i));
        term.setFormula(formula.get(i));
        termsList.add(term);


    }


    return termsList;
}

This has been wonderful for me. it's a lot of code, but it works, pretty quickly too actually. I notice no lag time, and there are nearly 30 "terms" in my XML, each with 5 attributes. just store your XML under res/xml (you will likely have to create the XML folder).

Answer 2

Not quite an answer, but you could also consider using Simple: http://simple.sourceforge.net/download/stream/doc/tutorial/tutorial.php#deserialize

It has a pretty comprehensize set of tutorials and if I remember correctly, it's quite small, so it shouldn't add much size to your application.

As with most of these XML parsing libraries, you'll need to create a data object of some sort to hold your deserialized data and you'll need to add some tags in that class to let the deserializer know what data you want to capture from the XML file and where to store it.