001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.util;
018
019import java.util.Date;
020import java.util.HashMap;
021
022import org.apache.activemq.command.ActiveMQDestination;
023
024public final class TypeConversionSupport {
025
026    static class ConversionKey {
027        final Class from;
028        final Class to;
029        final int hashCode;
030
031        public ConversionKey(Class from, Class to) {
032            this.from = from;
033            this.to = to;
034            this.hashCode = from.hashCode() ^ (to.hashCode() << 1);
035        }
036
037        public boolean equals(Object o) {
038            ConversionKey x = (ConversionKey)o;
039            return x.from == from && x.to == to;
040        }
041
042        public int hashCode() {
043            return hashCode;
044        }
045    }
046
047    interface Converter {
048        Object convert(Object value);
049    }
050
051    private static final HashMap<ConversionKey, Converter> CONVERSION_MAP = new HashMap<ConversionKey, Converter>();
052    static {
053        Converter toStringConverter = new Converter() {
054            public Object convert(Object value) {
055                return value.toString();
056            }
057        };
058        CONVERSION_MAP.put(new ConversionKey(Boolean.class, String.class), toStringConverter);
059        CONVERSION_MAP.put(new ConversionKey(Byte.class, String.class), toStringConverter);
060        CONVERSION_MAP.put(new ConversionKey(Short.class, String.class), toStringConverter);
061        CONVERSION_MAP.put(new ConversionKey(Integer.class, String.class), toStringConverter);
062        CONVERSION_MAP.put(new ConversionKey(Long.class, String.class), toStringConverter);
063        CONVERSION_MAP.put(new ConversionKey(Float.class, String.class), toStringConverter);
064        CONVERSION_MAP.put(new ConversionKey(Double.class, String.class), toStringConverter);
065
066        CONVERSION_MAP.put(new ConversionKey(String.class, Boolean.class), new Converter() {
067            public Object convert(Object value) {
068                return Boolean.valueOf((String)value);
069            }
070        });
071        CONVERSION_MAP.put(new ConversionKey(String.class, Byte.class), new Converter() {
072            public Object convert(Object value) {
073                return Byte.valueOf((String)value);
074            }
075        });
076        CONVERSION_MAP.put(new ConversionKey(String.class, Short.class), new Converter() {
077            public Object convert(Object value) {
078                return Short.valueOf((String)value);
079            }
080        });
081        CONVERSION_MAP.put(new ConversionKey(String.class, Integer.class), new Converter() {
082            public Object convert(Object value) {
083                return Integer.valueOf((String)value);
084            }
085        });
086        CONVERSION_MAP.put(new ConversionKey(String.class, Long.class), new Converter() {
087            public Object convert(Object value) {
088                return Long.valueOf((String)value);
089            }
090        });
091        CONVERSION_MAP.put(new ConversionKey(String.class, Float.class), new Converter() {
092            public Object convert(Object value) {
093                return Float.valueOf((String)value);
094            }
095        });
096        CONVERSION_MAP.put(new ConversionKey(String.class, Double.class), new Converter() {
097            public Object convert(Object value) {
098                return Double.valueOf((String)value);
099            }
100        });
101
102        Converter longConverter = new Converter() {
103            public Object convert(Object value) {
104                return Long.valueOf(((Number)value).longValue());
105            }
106        };
107        CONVERSION_MAP.put(new ConversionKey(Byte.class, Long.class), longConverter);
108        CONVERSION_MAP.put(new ConversionKey(Short.class, Long.class), longConverter);
109        CONVERSION_MAP.put(new ConversionKey(Integer.class, Long.class), longConverter);
110        CONVERSION_MAP.put(new ConversionKey(Date.class, Long.class), new Converter() {
111            public Object convert(Object value) {
112                return Long.valueOf(((Date)value).getTime());
113            }
114        });
115
116        Converter intConverter = new Converter() {
117            public Object convert(Object value) {
118                return Integer.valueOf(((Number)value).intValue());
119            }
120        };
121        CONVERSION_MAP.put(new ConversionKey(Byte.class, Integer.class), intConverter);
122        CONVERSION_MAP.put(new ConversionKey(Short.class, Integer.class), intConverter);
123
124        CONVERSION_MAP.put(new ConversionKey(Byte.class, Short.class), new Converter() {
125            public Object convert(Object value) {
126                return Short.valueOf(((Number)value).shortValue());
127            }
128        });
129
130        CONVERSION_MAP.put(new ConversionKey(Float.class, Double.class), new Converter() {
131            public Object convert(Object value) {
132                return new Double(((Number)value).doubleValue());
133            }
134        });
135        CONVERSION_MAP.put(new ConversionKey(String.class, ActiveMQDestination.class), new Converter() {
136            public Object convert(Object value) {
137                return ActiveMQDestination.createDestination((String)value, ActiveMQDestination.QUEUE_TYPE);
138            }
139        });
140    }
141
142    private TypeConversionSupport() {
143    }
144
145    public static Object convert(Object value, Class clazz) {
146
147        assert value != null && clazz != null;
148
149        if (value.getClass() == clazz) {
150            return value;
151        }
152
153        Converter c = CONVERSION_MAP.get(new ConversionKey(value.getClass(), clazz));
154        if (c == null) {
155            return null;
156        }
157        return c.convert(value);
158
159    }
160
161}