1 files changed, 124 insertions, 0 deletions
diff --git a/src/org/traccar/database/BaseObjectManager.java b/src/org/traccar/database/BaseObjectManager.java
new file mode 100644
index 000000000..d515fc2a9
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+++ b/src/org/traccar/database/BaseObjectManager.java
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+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed 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.traccar.database;
+
+import java.sql.SQLException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.traccar.helper.Log;
+import org.traccar.model.BaseModel;
+
+public class BaseObjectManager {
+
+    private final DataManager dataManager;
+
+    private Map<Long, BaseModel> items;
+    private Class<? extends BaseModel> baseClass;
+
+    protected BaseObjectManager(DataManager dataManager, Class<? extends BaseModel> baseClass) {
+        this.dataManager = dataManager;
+        this.baseClass = baseClass;
+        refreshItems();
+    }
+
+    protected final DataManager getDataManager() {
+        return dataManager;
+    }
+
+    protected final Class<? extends BaseModel> getBaseClass() {
+        return baseClass;
+    }
+
+    public final BaseModel getById(long itemId) {
+        return items.get(itemId);
+    }
+
+    public void refreshItems() {
+        if (dataManager != null) {
+            try {
+                Collection<? extends BaseModel> databaseItems = dataManager.getObjects(baseClass);
+                if (items == null) {
+                    items = new ConcurrentHashMap<>(databaseItems.size());
+                }
+                Set<Long> databaseItemIds = new HashSet<>();
+                for (BaseModel item : databaseItems) {
+                    databaseItemIds.add(item.getId());
+                    if (items.containsKey(item.getId())) {
+                        updateCachedItem(item);
+                    } else {
+                        addNewItem(item);
+                    }
+                }
+                for (Long cachedItemId : items.keySet()) {
+                    if (!databaseItemIds.contains(cachedItemId)) {
+                        removeCachedItem(cachedItemId);
+                    }
+                }
+            } catch (SQLException error) {
+                Log.warning(error);
+            }
+        }
+    }
+
+    protected void addNewItem(BaseModel item) {
+        items.put(item.getId(), item);
+    }
+
+    public void addItem(BaseModel item) throws SQLException {
+        dataManager.addObject(item);
+        addNewItem(item);
+    }
+
+    protected void updateCachedItem(BaseModel item) {
+        items.put(item.getId(), item);
+    }
+
+    public void updateItem(BaseModel item) throws SQLException {
+        dataManager.updateObject(item);
+        updateCachedItem(item);
+    }
+
+    protected void removeCachedItem(long itemId) {
+        items.remove(itemId);
+    }
+
+    public void removeItem(long itemId) throws SQLException {
+        BaseModel item = getById(itemId);
+        if (item != null) {
+            dataManager.removeObject(baseClass, itemId);
+            removeCachedItem(itemId);
+        }
+    }
+
+    public final <T> Collection<T> getItems(Class<T> clazz, Set<Long> itemIds) {
+        Collection<T> result = new LinkedList<>();
+        for (long itemId : itemIds) {
+            result.add((T) getById(itemId));
+        }
+        return result;
+    }
+
+    public Set<Long> getAllItems() {
+        return items.keySet();
+    }
+
+}