Compile time error in client code for simple example

[Gowher Naik]

Hi,
i am developing simple example which contains HashMap as shown below.
I am using jdk6.

  
@WebService
public class TestMapImpl {
	@WebMethod
	public HashMap<String, String> getMap() {
		HashMap<String, String> hash = new HashMap<String, String>();
		hash.put("key1", "value1");
		hash.put("key2", "value2");
		return hash;
	}
}

After publishing I generate required artifacts of above class using wsimport.
wsimport -p ch01.misc.wsimport -keep http://localhost:8888/testmap?wsdl

The client code for above example is shown below.

    
import ch01.misc.wsimport.HashMap;
import ch01.misc.wsimport.TestMapImpl;
import ch01.misc.wsimport.TestMapImplService;

public class MiscClient {
	public static void main(String[] args) {
		TestMapImplService impl=new TestMapImplService();
		TestMapImpl service=impl.getTestMapImplPort();
		HashMap testMap=service.getMap();
		testMap.get("key1");//Error The method get(String) is undefined for type HashMap 
	}
}

Now the problem is that i am getting compile time error in client code at last line.The method get(String) is undefined for type HashMap .
The code generated by wsimport for HashMap is shown below.

    
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;


/**
 * <p>Java class for hashMap complex type.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * 
 * <pre>
 * <complexType name="hashMap">
 *   <complexContent>
 *     <extension base="{http://misc.ch01/}abstractMap">
 *       <sequence>
 *       </sequence>
 *     </extension>
 *   </complexContent>
 * </complexType>
 * </pre>
 * 
 * 
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "hashMap")
public class HashMap
    extends AbstractMap
{


}

Please help me.

Thanks

[M Serentia]

I think you cannot put any java specific return type on any web service operation, because web sercies are all about interoperability think about some dot net client want to access your web service? they might have diffrent implementation for HashMap or so...

[Ivan Krizsan]

Hi!
The problem is that there is no representation of maps in an XML schema.
You can, however, translate the map to something that can be represented using an array and a POJO.
The array is an array of POJOs an each POJO instance holds a key and a value.
The key and value are of some simple type, like String, Number or similar.

Here is a code example:

    // In the web service endpoint implementation class:
    public KeyValueHolder[] someMethod()
    {
        Map<String, String> theMap = new HashMap<String, String>();

        ...

        KeyValueHolder[] theResult = new KeyValueHolder[theMap.size()];
        int i = 0;

        for (String theKey : theMap.keySet())
        {
            KeyValueHolder theKV = new KeyValueHolder();
            theKV.setKey(theKey);
            theKV.setValue(theMap.get(theKey));
            theResult[i++] = theKV;
        }

        return theResult;
    }

    // In another file, KeyValueHolder.java
    public class KeyValueHolder {
        private String key;
        private String value;

        // ...and getters and setters for each field.
    }

Note that this will not readily be transformed to a map, so the client has to have some additional information, apart from the WSDL, as to how to treat this data.
Best wishes!