org.apache.activemq.artemis.core.management.impl.view.ActiveMQAbstractView Maven / Gradle / Ivy
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* 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 org.apache.activemq.artemis.core.management.impl.view;
import javax.json.JsonArrayBuilder;
import javax.json.JsonObject;
import javax.json.JsonObjectBuilder;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import org.apache.activemq.artemis.api.core.JsonUtil;
import org.apache.activemq.artemis.core.management.impl.view.predicate.ActiveMQFilterPredicate;
import org.apache.activemq.artemis.utils.JsonLoader;
public abstract class ActiveMQAbstractView {
private static final String FILTER_FIELD = "field";
private static final String FILTER_OPERATION = "operation";
private static final String FILTER_VALUE = "value";
private static final String SORT_ORDER = "sortOrder";
private static final String SORT_COLUMN = "sortColumn";
protected Collection collection;
protected ActiveMQFilterPredicate predicate;
protected String sortColumn;
protected String sortOrder;
protected String options;
public ActiveMQAbstractView() {
this.sortColumn = getDefaultOrderColumn();
this.sortOrder = "asc";
}
public void setCollection(Collection collection) {
this.collection = collection;
}
public String getResultsAsJson(int page, int pageSize) {
JsonObjectBuilder obj = JsonLoader.createObjectBuilder();
JsonArrayBuilder array = JsonLoader.createArrayBuilder();
collection = collection.stream().filter(getPredicate()).collect(Collectors.toList());
for (T element : getPagedResult(page, pageSize)) {
JsonObjectBuilder jsonObjectBuilder = toJson(element);
//toJson() may return a null
if (jsonObjectBuilder != null) {
array.add(jsonObjectBuilder);
}
}
obj.add("data", array);
obj.add("count", collection.size());
return obj.build().toString();
}
public List getPagedResult(int page, int pageSize) {
List builder = new ArrayList<>();
int start = (page - 1) * pageSize;
int end = Math.min(page * pageSize, collection.size());
int i = 0;
for (T e : collection.stream().sorted(getComparator()).collect(Collectors.toList())) {
if (i >= start && i < end) {
builder.add(e);
}
i++;
}
return Collections.unmodifiableList(builder);
}
public Predicate getPredicate() {
return predicate;
}
public Comparator getComparator() {
return (left, right) -> {
try {
Object leftValue = getField(left, sortColumn);
Object rightValue = getField(right, sortColumn);
if (leftValue instanceof Comparable && rightValue instanceof Comparable) {
if (sortOrder.equals("desc")) {
return ((Comparable) rightValue).compareTo(leftValue);
} else {
return ((Comparable) leftValue).compareTo(rightValue);
}
}
return 0;
} catch (Exception e) {
//LOG.info("Exception sorting destinations", e);
return 0;
}
};
}
abstract Object getField(T t, String fieldName);
public void setOptions(String options) {
JsonObject json = JsonUtil.readJsonObject(options);
if (predicate != null) {
predicate.setField(json.getString(FILTER_FIELD));
predicate.setOperation(json.getString(FILTER_OPERATION));
predicate.setValue(json.getString(FILTER_VALUE));
if (json.containsKey(SORT_COLUMN) && json.containsKey(SORT_ORDER)) {
this.sortColumn = json.getString(SORT_COLUMN);
this.sortOrder = json.getString(SORT_ORDER);
}
}
}
public abstract Class getClassT();
public abstract JsonObjectBuilder toJson(T obj);
public abstract String getDefaultOrderColumn();
/**
* JsonObjectBuilder will throw an NPE if a null value is added. For this reason we check for null explicitly when
* adding objects.
*
* @param o
* @return
*/
protected String toString(Object o) {
return o == null ? "" : o.toString();
}
}