com.adaptris.util.text.mime.InputStreamDataSource.java Source code

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Here is the source code for com.adaptris.util.text.mime.InputStreamDataSource.java

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/*
 * Copyright 2015 Adaptris Ltd.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/

package com.adaptris.util.text.mime;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.activation.DataSource;
import javax.mail.MessagingException;
import javax.mail.internet.InternetHeaders;
import javax.mail.util.SharedByteArrayInputStream;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;

import com.adaptris.core.util.Args;

public class InputStreamDataSource implements DataSource, MimeConstants, MimeHeaders {

    private InternetHeaders headers = null;
    private String contentType = null;
    private String messageId = null;
    private byte[] wrappedBytes;

    private InputStreamDataSource() {
    }

    /** Constructor.
     *  @param input the input stream.
     *  @throws IOException if there was an error reading the stream.
     *  @throws MessagingException if there was an error initialising the
     *  datasource.
     */
    public InputStreamDataSource(InputStream input) throws IOException, MessagingException {
        this();
        initialise(input);
    }

    private void initialise(InputStream input) throws IOException, MessagingException {
        headers = new InternetHeaders(input);
        initContent(input);
    }

    @Override
    public String getContentType() {
        if (contentType == null) {
            contentType = get(HEADER_CONTENT_TYPE);
        }
        return contentType;
    }

    @Override
    public InputStream getInputStream() throws IOException {
        return new SharedByteArrayInputStream(wrappedBytes);
    }

    @Override
    public String getName() {
        if (messageId == null) {
            messageId = get(HEADER_MESSAGE_ID);
        }
        return messageId;
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
        throw new UnsupportedOperationException();
    }

    private void initContent(InputStream in) throws IOException {
        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            IOUtils.copy(in, out);
            wrappedBytes = out.toByteArray();
        }
    }

    @Override
    public InternetHeaders getHeaders() {
        return headers;
    }

    private String get(String headerName) {
        String result = null;
        try {
            String[] s = Args.notNull(headers.getHeader(headerName), headerName);
            result = s[0];
        } catch (IllegalArgumentException e) {

        }
        return StringUtils.defaultIfEmpty(result, "");
    }
}