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     */
017    package org.apache.camel;
018    
019    
020    /**
021     * A pluggable strategy to be able to convert objects <a
022     * href="http://camel.apache.org/type-converter.html">to different
023     * types</a> such as to and from String, InputStream/OutputStream,
024     * Reader/Writer, Document, byte[], ByteBuffer etc
025     * 
026     * @version 
027     */
028    public interface TypeConverter {
029    
030        /**
031         * Converts the value to the specified type
032         *
033         * @param type the requested type
034         * @param value the value to be converted
035         * @return the converted value, or <tt>null</tt> if not possible to convert
036         * @throws TypeConversionException is thrown if error during type conversion
037         */
038        <T> T convertTo(Class<T> type, Object value) throws TypeConversionException;
039    
040        /**
041         * Converts the value to the specified type in the context of an exchange
042         * <p/>
043         * Used when conversion requires extra information from the current
044         * exchange (such as encoding).
045         *
046         * @param type the requested type
047         * @param exchange the current exchange
048         * @param value the value to be converted
049         * @return the converted value, or <tt>null</tt> if not possible to convert
050         * @throws TypeConversionException is thrown if error during type conversion
051         */
052        <T> T convertTo(Class<T> type, Exchange exchange, Object value) throws TypeConversionException;
053    
054        /**
055         * Converts the value to the specified type
056         *
057         * @param type the requested type
058         * @param value the value to be converted
059         * @return the converted value, is never <tt>null</tt>
060         * @throws TypeConversionException is thrown if error during type conversion
061         * @throws NoTypeConversionAvailableException} if no type converters exists to convert to the given type
062         */
063        <T> T mandatoryConvertTo(Class<T> type, Object value) throws TypeConversionException, NoTypeConversionAvailableException;
064    
065        /**
066         * Converts the value to the specified type in the context of an exchange
067         * <p/>
068         * Used when conversion requires extra information from the current
069         * exchange (such as encoding).
070         *
071         * @param type the requested type
072         * @param exchange the current exchange
073         * @param value the value to be converted
074         * @return the converted value, is never <tt>null</tt>
075         * @throws TypeConversionException is thrown if error during type conversion
076         * @throws NoTypeConversionAvailableException} if no type converters exists to convert to the given type
077         */
078        <T> T mandatoryConvertTo(Class<T> type, Exchange exchange, Object value) throws TypeConversionException, NoTypeConversionAvailableException;
079    
080        /**
081         * Tries to convert the value to the specified type,
082         * returning <tt>null</tt> if not possible to convert.
083         * <p/>
084         * This method will <b>not</b> throw an exception if an exception occurred during conversion.
085         *
086         * @param type the requested type
087         * @param value the value to be converted
088         * @return the converted value, or <tt>null</tt> if not possible to convert
089         */
090        <T> T tryConvertTo(Class<T> type, Object value);
091    
092        /**
093         * Tries to convert the value to the specified type in the context of an exchange,
094         * returning <tt>null</tt> if not possible to convert.
095         * <p/>
096         * This method will <b>not</b> throw an exception if an exception occurred during conversion.
097         * Converts the value to the specified type in the context of an exchange
098         * <p/>
099         * Used when conversion requires extra information from the current
100         * exchange (such as encoding).
101         *
102         * @param type the requested type
103         * @param exchange the current exchange
104         * @param value the value to be converted
105         * @return the converted value, or <tt>null</tt> if not possible to convert
106         */
107        <T> T tryConvertTo(Class<T> type, Exchange exchange, Object value);
108    
109    }