PropertyAccessorBuilder.java

/*
 * Copyright 2014 Daniel Bechler
 *
 * 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 de.danielbechler.diff.introspection;

import java.lang.reflect.Method;

/**
 * @author Daniel Bechler
 */
final class PropertyAccessorBuilder
{
	private PropertyAccessorBuilder()
	{
	}

	public static NameAndType forPropertyOf(final Class<?> targetType)
	{
		final Builder builder = new Builder();
		builder.targetType = targetType;
		return builder;
	}

	public interface Buildable
	{
		PropertyAccessor build();
	}

	public interface NameAndType
	{
		ReadOnly property(String name, Class<?> type);
	}

	public interface ReadOnly extends Buildable
	{
		Buildable readOnly(boolean readOnly);
	}

	public static class Builder implements NameAndType, ReadOnly, Buildable
	{
		private String propertyName;
		private Class<?> propertyType;
		private Class<?> targetType;
		private boolean readOnly;

		public ReadOnly property(final String name, final Class<?> type)
		{
			this.propertyName = name;
			this.propertyType = type;
			return this;
		}

		public Buildable readOnly(final boolean readOnly)
		{
			this.readOnly = readOnly;
			return this;
		}

		public PropertyAccessor build()
		{
			try
			{
				final Method readMethod = targetType.getDeclaredMethod(name("get"));
				final Method writeMethod;
				if (readOnly)
				{
					writeMethod = null;
				}
				else
				{
					writeMethod = targetType.getDeclaredMethod(name("set"), propertyType);
				}
				return new PropertyAccessor(propertyName, readMethod, writeMethod);
			}
			catch (final NoSuchMethodException e)
			{
				throw new RuntimeException(e);
			}
		}

		private String name(final String prefix)
		{
			return prefix + Character.toUpperCase(propertyName.charAt(0)) + propertyName.substring(1);
		}
	}
}