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.camel.model.transformer;
018
019import javax.xml.bind.annotation.XmlAccessType;
020import javax.xml.bind.annotation.XmlAccessorType;
021import javax.xml.bind.annotation.XmlAttribute;
022import javax.xml.bind.annotation.XmlType;
023
024import org.apache.camel.CamelContext;
025import org.apache.camel.model.InputTypeDefinition;
026import org.apache.camel.model.OutputTypeDefinition;
027import org.apache.camel.spi.DataType;
028import org.apache.camel.spi.Metadata;
029import org.apache.camel.spi.Transformer;
030
031/**
032 * <p>Represents a {@link Transformer} which declaratively transforms message content
033 * according to the input type declared by {@link InputTypeDefinition} and/or output type
034 * declared by {@link OutputTypeDefinition}.</p>
035 * <p>If you specify from='java:com.example.ABC' and to='xml:XYZ', the transformer
036 * will be picked up when current message type is 'java:com.example.ABC' and expected
037 * message type is 'xml:XYZ'.
038 * If you specify from='java' to='xml', then it will be picked up for all of java
039 * to xml transformation.
040 * Also it's possible to specify scheme='xml' so that the transformer will be picked up
041 * for all of java to xml and xml to java transformation.</p>
042 * 
043 * {@see Transformer}
044 * {@see InputTypeDefinition}
045 * {@see OutputTypeDefinition}
046 */
047@Metadata(label = "transformation")
048@XmlType(name = "transformer")
049@XmlAccessorType(XmlAccessType.FIELD)
050public abstract class TransformerDefinition {
051
052    @XmlAttribute
053    private String scheme;
054    @XmlAttribute
055    private String fromType;
056    @XmlAttribute
057    private String toType;
058
059    public Transformer createTransformer(CamelContext context) throws Exception {
060        return doCreateTransformer(context);
061    };
062
063    protected abstract Transformer doCreateTransformer(CamelContext context) throws Exception;
064
065    public String getScheme() {
066        return scheme;
067    }
068
069    /**
070     * Set a scheme name supported by the transformer.
071     * If you specify 'csv', the transformer will be picked up for all of 'csv' from/to
072     * Java transformation. Note that the scheme matching is performed only when
073     * no exactly matched transformer exists.
074     *
075     * @param scheme scheme name
076     */
077    public void setScheme(String scheme) {
078        this.scheme = scheme;
079    }
080
081    public String getFromType() {
082        return fromType;
083    }
084
085    /**
086     * Set the 'from' data type name.
087     * If you specify 'xml:XYZ', the transformer will be picked up if source type is
088     * 'xml:XYZ'. If you specify just 'xml', the transformer matches with all of
089     * 'xml' source type like 'xml:ABC' or 'xml:DEF'.
090     * 
091     * @param from 'from' data type name
092     */
093    public void setFromType(String from) {
094        this.fromType = from;
095    }
096
097    /**
098     * Set the 'from' data type using Java class.
099     *
100     * @param clazz 'from' Java class
101     */
102    public void setFromType(Class<?> clazz) {
103        this.fromType = new DataType(clazz).toString();
104    }
105
106    public String getToType() {
107        return toType;
108    }
109
110    /**
111     * Set the 'to' data type name.
112     * If you specify 'json:XYZ', the transformer will be picked up if destination type is
113     * 'json:XYZ'. If you specify just 'json', the transformer matches with all of
114     * 'json' destination type like 'json:ABC' or 'json:DEF'.
115     *
116     * @param to 'to' data type name
117     */
118    public void setToType(String to) {
119        this.toType = to;
120    }
121
122    /**
123     * Set the 'to' data type using Java class.
124     *
125     * @param clazz 'to' Java class
126     */
127    public void setToType(Class<?> clazz) {
128        this.toType = new DataType(clazz).toString();
129    }
130
131}
132