/*
* Copyright 2014-2014 Chen Lichao
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cn.chenlichao.wmi4j;
import org.jinterop.dcom.common.JIException;
import org.jinterop.dcom.core.IJIComObject;
import org.jinterop.dcom.core.JIArray;
import org.jinterop.dcom.core.JIVariant;
import org.jinterop.dcom.impls.JIObjectFactory;
import org.jinterop.dcom.impls.automation.IJIDispatch;
import org.jinterop.dcom.impls.automation.IJIEnumVariant;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Iterator;
/**
* Abstract object collection.
* Created by chenlichao on 14-7-23.
*/
abstract class AbstractWbemSet<E extends AbstractScriptingObject> extends AbstractScriptingObject {
AbstractWbemSet(IJIDispatch dispatch) {
super(dispatch);
}
/**
* Get how many items are in this SWbemObjectSet collection. This property is read-only.
*
* <p>One thing to be careful of when using Count is that WMI does not keep a running tally of the number of items in a collection.
* If you request Count for a collection, WMI cannot instantly respond with a number;
* instead, it must literally count the items, enumerating the entire collection.
* For a collection that has relatively few items, such as services, this enumeration likely takes less than a second.
* Counting the number of events in an event log collection, however, can take considerably longer.</p>
* <p>And then suppose you want to display the property values for every event in the collection.
* If so, WMI will have to enumerate the entire collection a second time.</p>
*
* <p><strong>Note: </strong>If you attempt to get this property from an SWbemObjectSet object
* that is returned from a method where the specified flags are included the wbemFlagForwardOnly flag,
* you will get an wbemErrFailed error.</p>
* @return The count of items in this SWbemObjectSet collection.
* @throws WMIException
*/
public int getCount() throws WMIException {
try {
JIVariant result = dispatch.get("Count");
if(result == null) {
throw new WMIException(0, "Get count property failed.");
}
return result.getObjectAsInt();
} catch (JIException e) {
throw new WMIException(e);
}
}
/**
* Create a iterator of this object set.
* @return Iterator instance.
* @throws WMIException
*/
public Iterator<E> iterator() throws WMIException {
try {
JIVariant variant = dispatch.get("_NewEnum");
IJIComObject setObj = variant.getObjectAsComObject();
final IJIEnumVariant enumVariant = (IJIEnumVariant) JIObjectFactory.narrowObject(setObj.queryInterface(IJIEnumVariant.IID));
final int count = getCount();
final Class<?> elementClass = getElementType();
return new Iterator<E>() {
private int index = 0;
@Override
public boolean hasNext() {
return index < count;
}
@Override
public E next() {
try {
Object[] objs = enumVariant.next(1);
JIArray array = (JIArray)objs[0];
Object[] arrayObj = (Object[])array.getArrayInstance();
JIVariant ele = (JIVariant)arrayObj[0];
IJIDispatch dispatch = (IJIDispatch) JIObjectFactory.narrowObject(ele.getObjectAsComObject());
@SuppressWarnings("unchecked")
E result = (E)elementClass.getDeclaredConstructor(IJIDispatch.class).newInstance(dispatch);
index++;
return result;
} catch (Exception e) {
index = count;
throw new IllegalStateException(e.getMessage(), e);
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
} catch (JIException e) {
throw new WMIException(e);
}
}
private Class<?> getElementType() {
Type superClass = this.getClass().getGenericSuperclass();
Type returnType = ((ParameterizedType) superClass).getActualTypeArguments()[0];
return (Class<?>)returnType;
}
}