    001// Copyright 2006 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.services;
    016
    017import static org.apache.tapestry5.commons.util.CollectionFactory.newMap;
    018
    019import java.util.Map;
    020
    021/**
    022 * Support code for generating code (used when transforming component classes).
    023 */
    024public final class TransformUtils
    025{
    026    private static final Map<String, PrimitiveTypeInfo> nameToInfo = newMap();
    027
    028    private static final Map<Class, PrimitiveTypeInfo> classToInfo = newMap();
    029
    030    static class PrimitiveTypeInfo
    031    {
    032        private final Class wrapperType;
    033
    034        private final String unwrapperMethodName;
    035
    036        private final String defaultValue;
    037
    038        public PrimitiveTypeInfo(Class wrapperType, String unwrapperMethodName, String defaultValue)
    039        {
    040            this.wrapperType = wrapperType;
    041            this.unwrapperMethodName = unwrapperMethodName;
    042            this.defaultValue = defaultValue;
    043        }
    044    }
    045
    046    static
    047    {
    048        add(boolean.class, Boolean.class, "booleanValue", "false");
    049        add(byte.class, Byte.class, "byteValue", "0");
    050        add(char.class, Character.class, "charValue", "0");
    051        add(short.class, Short.class, "shortValue", "0");
    052        add(int.class, Integer.class, "intValue", "0");
    053        add(long.class, Long.class, "longValue", "0L");
    054        add(float.class, Float.class, "floatValue", "0.0f");
    055        add(double.class, Double.class, "doubleValue", "0.0d");
    056    }
    057
    058    private TransformUtils()
    059    {
    060    }
    061
    062    private static void add(Class primitiveType, Class wrapperType, String unwrapperMethodName, String defaultValue)
    063    {
    064        PrimitiveTypeInfo info = new PrimitiveTypeInfo(wrapperType, unwrapperMethodName, defaultValue);
    065
    066        classToInfo.put(primitiveType, info);
    067        nameToInfo.put(primitiveType.getName(), info);
    068    }
    069
    070    /**
    071     * Returns true if the specified type is a primitive type.
    072     */
    073    public static boolean isPrimitive(String type)
    074    {
    075        return nameToInfo.containsKey(type);
    076    }
    077
    078    /**
    079     * Returns the name of wrapper type for a given input type. For primitive types, returns the wrapper type. For other
    080     * types, returns the input type name.
    081     *
    082     * @param type primitive type name, or fully qualified class name
    083     */
    084    public static String getWrapperTypeName(String type)
    085    {
    086        PrimitiveTypeInfo info = nameToInfo.get(type);
    087
    088        return info == null ? type : info.wrapperType.getName();
    089    }
    090
    091    /**
    092     * For primitive types, returns the method on the <em>wrapper type</em> that converts back to the primitive.
    093     *
    094     * @param type the primitive type
    095     * @return the method of the corresponding wrapper type, or null if type is not a primitive type
    096     */
    097    public static String getUnwrapperMethodName(String type)
    098    {
    099        PrimitiveTypeInfo info = nameToInfo.get(type);
    100
    101        return info == null ? null : info.unwrapperMethodName;
    102    }
    103
    104    /**
    105     * Returns the wrapper type for a given input type. For primitive types, returns the wrapper type. For other types,
    106     * returns the type itself.
    107     *
    108     * @param type primitive or object type
    109     */
    110    public static Class getWrapperType(Class type)
    111    {
    112        PrimitiveTypeInfo info = classToInfo.get(type);
    113
    114        return info == null ? type : info.wrapperType;
    115    }
    116
    117    /**
    118     * Returns the default value for a type. This is the string "null" for most types, or a literal value for primitive
    119     * types.
    120     */
    121    public static String getDefaultValue(String type)
    122    {
    123        PrimitiveTypeInfo info = nameToInfo.get(type);
    124
    125        return info == null ? "null" : info.defaultValue;
    126    }
    127}