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.commons.mail2.jakarta.resolver;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.net.URL;
022
023import jakarta.activation.DataSource;
024import jakarta.activation.FileTypeMap;
025import jakarta.mail.util.ByteArrayDataSource;
026
027/**
028 * Creates a {@code DataSource} based on an class path.
029 *
030 * @since 1.3
031 */
032public class DataSourceClassPathResolver extends DataSourceBaseResolver {
033    /** The base string of the resource relative to the classpath when resolving relative paths */
034    private final String classPathBase;
035
036    /**
037     * Constructs a new instance.
038     */
039    public DataSourceClassPathResolver() {
040        this("/");
041    }
042
043    /**
044     * Constructs a new instance.
045     *
046     * @param classPathBase a base class path
047     */
048    public DataSourceClassPathResolver(final String classPathBase) {
049        this(classPathBase, false);
050    }
051
052    /**
053     * Constructs a new instance.
054     *
055     * @param classPathBase a base class path
056     * @param lenient       shall we ignore resources not found or throw an exception?
057     */
058    public DataSourceClassPathResolver(final String classPathBase, final boolean lenient) {
059        super(lenient);
060        this.classPathBase = classPathBase.endsWith("/") ? classPathBase : classPathBase + "/";
061    }
062
063    /**
064     * Gets the class path base.
065     *
066     * @return the classPathBase
067     */
068    public String getClassPathBase() {
069        return classPathBase;
070    }
071
072    /**
073     * Returns the resource name for a given resource location.
074     *
075     * @param resourceLocation the resource location
076     * @return {@link #getClassPathBase()} + {@code resourceLocation}
077     * @see #getClassPathBase()
078     */
079    private String getResourceName(final String resourceLocation) {
080        return (getClassPathBase() + resourceLocation).replace("//", "/");
081    }
082
083    /** {@inheritDoc} */
084    @Override
085    public DataSource resolve(final String resourceLocation) throws IOException {
086        return resolve(resourceLocation, isLenient());
087    }
088
089    /** {@inheritDoc} */
090    @Override
091    public DataSource resolve(final String resourceLocation, final boolean isLenient) throws IOException {
092        try {
093            if (!isCid(resourceLocation) && !isHttpUrl(resourceLocation)) {
094                final String mimeType = FileTypeMap.getDefaultFileTypeMap().getContentType(resourceLocation);
095                final String resourceName = getResourceName(resourceLocation);
096                try (InputStream inputStream = DataSourceClassPathResolver.class.getResourceAsStream(resourceName)) {
097                    if (inputStream == null) {
098                        if (isLenient) {
099                            return null;
100                        }
101                        throw new IOException("The following class path resource was not found : " + resourceLocation);
102                    }
103                    final ByteArrayDataSource ds = new ByteArrayDataSource(inputStream, mimeType);
104                    // EMAIL-125: set the name of the DataSource to the normalized resource URL
105                    // similar to other DataSource implementations, e.g. FileDataSource, URLDataSource
106                    final URL resource = DataSourceClassPathResolver.class.getResource(resourceName);
107                    if (resource != null) {
108                        ds.setName(resource.toString());
109                    } else if (isLenient) {
110                        return null;
111                    } else {
112                        throw new IOException("The following class path resource was not found : " + resourceName);
113                    }
114                    return ds;
115                }
116            }
117            return null;
118        } catch (final IOException e) {
119            if (isLenient) {
120                return null;
121            }
122            throw e;
123        }
124    }
125}