Implements better schema management

l2jserver2-common/src/main/java/com/l2jserver/util/QPathUtils.java

@@ -0,0 +1,173 @@
+/*
+ * This file is part of l2jserver2 <l2jserver2.com>.
+ *
+ * l2jserver2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * l2jserver2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with l2jserver2.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.l2jserver.util;
+
+import java.lang.reflect.Field;
+
+import com.l2jserver.service.database.ddl.annotation.ColumnAutoIncrement;
+import com.l2jserver.service.database.ddl.annotation.ColumnDefault;
+import com.l2jserver.service.database.ddl.annotation.ColumnNullable;
+import com.l2jserver.service.database.ddl.annotation.ColumnSize;
+import com.l2jserver.util.transformer.Transformer;
+import com.l2jserver.util.transformer.TransformerFactory;
+import com.mysema.query.sql.RelationalPath;
+import com.mysema.query.types.Path;
+
+/**
+ * Class serving several utilities for {@link Path} and {@link RelationalPath}
+ * 
+ * @author <a href="http://www.rogiel.com">Rogiel</a>
+ */
+public class QPathUtils {
+	/**
+	 * Returns the {@link Path} represented by <code>name</code> within the
+	 * given {@link RelationalPath}
+	 * 
+	 * @param relationalPath
+	 *            the {@link RelationalPath}
+	 * @param name
+	 *            the {@link Path} name
+	 * @return the {@link Path} instance, if existent
+	 */
+	public static Path<?> getPath(RelationalPath<?> relationalPath, String name) {
+		for (final Path<?> path : relationalPath.getColumns()) {
+			if (path.getMetadata().getExpression().toString().equals(name))
+				return path;
+		}
+		return null;
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path} to be searched in its root entity
+	 * @return the {@link Field} holding <code>path</code>
+	 */
+	public static Field getReflectionField(Path<?> path) {
+		return ClassUtils.getFieldWithValue(path.getMetadata().getParent(), path);
+	}
+
+	/**
+	 * @param relationalPath
+	 *            the {@link RelationalPath}
+	 * @param pathName
+	 *            the {@link Path} name
+	 * @return the {@link Field} holding <code>pathName</code>
+	 * @see #getPath(RelationalPath, String)
+	 */
+	public static Field getRefelctionField(RelationalPath<?> relationalPath,
+			String pathName) {
+		return ClassUtils.getFieldWithValue(relationalPath,
+				getPath(relationalPath, pathName));
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path}
+	 * @return the column maximum size
+	 */
+	public static int getColumnSize(Path<?> path) {
+		final Field field = getReflectionField(path);
+		if(field == null)
+			return 0;
+		final ColumnSize size = field.getAnnotation(ColumnSize.class);
+		if (size != null)
+			return size.value();
+		return -1;
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path}
+	 * @return whether the column is auto incrementable or not
+	 */
+	public static boolean isAutoIncrementable(Path<?> path) {
+		final Field field = getReflectionField(path);
+		if(field == null)
+			return false;
+		final ColumnAutoIncrement autoInc = field
+				.getAnnotation(ColumnAutoIncrement.class);
+		if (autoInc != null)
+			return true;
+		return false;
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path}
+	 * @return whether the column can be <code>null</code>
+	 */
+	public static boolean isNullable(Path<?> path) {
+		final Field field = getReflectionField(path);
+		if(field == null)
+			return false;
+		final ColumnNullable nullable = field
+				.getAnnotation(ColumnNullable.class);
+		if (nullable == null) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path}
+	 * @return <code>true</code> if the column has an default value
+	 */
+	public static boolean hasDefaultValue(Path<?> path) {
+		final Field field = getReflectionField(path);
+		if(field == null)
+			return false;
+		final ColumnDefault def = field.getAnnotation(ColumnDefault.class);
+		if (def == null) {
+			return false;
+		} else {
+			return true;
+		}
+	}
+
+	/**
+	 * @param path
+	 *            the {@link Path}
+	 * @return the column default value
+	 */
+	public static String getDefaultUntransformedValue(Path<?> path) {
+		final Field field = getReflectionField(path);
+		if(field == null)
+			return null;
+		final ColumnDefault def = field.getAnnotation(ColumnDefault.class);
+		if (def != null)
+			return def.value();
+		return null;
+	}
+
+	/**
+	 * @param <T>
+	 *            the column return type
+	 * @param path
+	 *            the {@link Path}
+	 * @return the column default value (already transformed)
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T> T getDefaultValue(Path<T> path) {
+		@SuppressWarnings("rawtypes")
+		final Transformer transformer = TransformerFactory.getTransfromer(path
+				.getType());
+		return (T) transformer.untransform(path.getType(),
+				getDefaultUntransformedValue(path));
+	}
+}