javax.mail.internet.ContentType.java Source code

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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://oss.oracle.com/licenses/CDDL+GPL-1.1
 * or LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
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 * If you wish your version of this file to be governed by only the CDDL or
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 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
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 */

package javax.mail.internet;

import javax.mail.*;
import java.util.*;
import java.io.*;

/**
 * This class represents a MIME Content-Type value. It provides
 * methods to parse a Content-Type string into individual components
 * and to generate a MIME style Content-Type string.
 *
 * @author  John Mani
 */

public class ContentType {

    private String primaryType; // primary type
    private String subType; // subtype
    private ParameterList list; // parameter list

    /**
     * No-arg Constructor.
     */
    public ContentType() {
    }

    /**
     * Constructor.
     *
     * @param   primaryType   primary type
     * @param   subType   subType
     * @param   list   ParameterList
     */
    public ContentType(String primaryType, String subType, ParameterList list) {
        this.primaryType = primaryType;
        this.subType = subType;
        this.list = list;
    }

    /**
     * Constructor that takes a Content-Type string. The String
     * is parsed into its constituents: primaryType, subType
     * and parameters. A ParseException is thrown if the parse fails. 
     *
     * @param   s   the Content-Type string.
     * @exception   ParseException if the parse fails.
     */
    public ContentType(String s) throws ParseException {
        HeaderTokenizer h = new HeaderTokenizer(s, HeaderTokenizer.MIME);
        HeaderTokenizer.Token tk;

        // First "type" ..
        tk = h.next();
        if (tk.getType() != HeaderTokenizer.Token.ATOM)
            throw new ParseException(
                    "In Content-Type string <" + s + ">" + ", expected MIME type, got " + tk.getValue());
        primaryType = tk.getValue();

        // The '/' separator ..
        tk = h.next();
        if ((char) tk.getType() != '/')
            throw new ParseException("In Content-Type string <" + s + ">" + ", expected '/', got " + tk.getValue());

        // Then "subType" ..
        tk = h.next();
        if (tk.getType() != HeaderTokenizer.Token.ATOM)
            throw new ParseException(
                    "In Content-Type string <" + s + ">" + ", expected MIME subtype, got " + tk.getValue());
        subType = tk.getValue();

        // Finally parameters ..
        String rem = h.getRemainder();
        if (rem != null)
            list = new ParameterList(rem);
    }

    /**
     * Return the primary type.
     * @return the primary type
     */
    public String getPrimaryType() {
        return primaryType;
    }

    /**
     * Return the subType.
     * @return the subType
     */
    public String getSubType() {
        return subType;
    }

    /**
     * Return the MIME type string, without the parameters.
     * The returned value is basically the concatenation of
     * the primaryType, the '/' character and the secondaryType.
     *
     * @return the type
     */
    public String getBaseType() {
        if (primaryType == null || subType == null)
            return "";
        return primaryType + '/' + subType;
    }

    /**
     * Return the specified parameter value. Returns <code>null</code>
     * if this parameter is absent.
     *
     * @param   name   the parameter name
     * @return   parameter value
     */
    public String getParameter(String name) {
        if (list == null)
            return null;

        return list.get(name);
    }

    /**
     * Return a ParameterList object that holds all the available 
     * parameters. Returns null if no parameters are available.
     *
     * @return   ParameterList
     */
    public ParameterList getParameterList() {
        return list;
    }

    /**
     * Set the primary type. Overrides existing primary type.
     * @param   primaryType   primary type
     */
    public void setPrimaryType(String primaryType) {
        this.primaryType = primaryType;
    }

    /**
     * Set the subType.  Replaces the existing subType.
     * @param   subType   the subType
     */
    public void setSubType(String subType) {
        this.subType = subType;
    }

    /**
     * Set the specified parameter. If this parameter already exists,
     * it is replaced by this new value.
     *
     * @param   name   parameter name
     * @param   value   parameter value
     */
    public void setParameter(String name, String value) {
        if (list == null)
            list = new ParameterList();

        list.set(name, value);
    }

    /**
     * Set a new ParameterList.
     * @param   list   ParameterList
     */
    public void setParameterList(ParameterList list) {
        this.list = list;
    }

    /**
     * Retrieve a RFC2045 style string representation of
     * this Content-Type. Returns an empty string if
     * the conversion failed.
     *
     * @return   RFC2045 style string
     */
    @Override
    public String toString() {
        if (primaryType == null || subType == null) // need both
            return "";

        StringBuilder sb = new StringBuilder();
        sb.append(primaryType).append('/').append(subType);
        if (list != null)
            // append the parameter list 
            // use the length of the string buffer + the length of
            // the header name formatted as follows "Content-Type: "
            sb.append(list.toString(sb.length() + 14));

        return sb.toString();
    }

    /**
     * Match with the specified ContentType object. This method
     * compares <strong>only the <code>primaryType</code> and 
     * <code>subType</code> </strong>. The parameters of both operands
     * are ignored. <p>
     *
     * For example, this method will return <code>true</code> when
     * comparing the ContentTypes for <strong>"text/plain"</strong>
     * and <strong>"text/plain; charset=foobar"</strong>.
     *
     * If the <code>subType</code> of either operand is the special
     * character '*', then the subtype is ignored during the match. 
     * For example, this method will return <code>true</code> when 
     * comparing the ContentTypes for <strong>"text/plain"</strong> 
     * and <strong>"text/*" </strong>
     *
     * @param   cType   ContentType to compare this against
     * @return   true if it matches
     */
    public boolean match(ContentType cType) {
        // Match primaryType
        if (!((primaryType == null && cType.getPrimaryType() == null)
                || (primaryType != null && primaryType.equalsIgnoreCase(cType.getPrimaryType()))))
            return false;

        String sType = cType.getSubType();

        // If either one of the subTypes is wildcarded, return true
        if ((subType != null && subType.startsWith("*")) || (sType != null && sType.startsWith("*")))
            return true;

        // Match subType
        return (subType == null && sType == null) || (subType != null && subType.equalsIgnoreCase(sType));
    }

    /**
     * Match with the specified content-type string. This method
     * compares <strong>only the <code>primaryType</code> and 
     * <code>subType</code> </strong>.
     * The parameters of both operands are ignored. <p>
     *
     * For example, this method will return <code>true</code> when
     * comparing the ContentType for <strong>"text/plain"</strong>
     * with <strong>"text/plain; charset=foobar"</strong>.
     *
     * If the <code>subType</code> of either operand is the special 
     * character '*', then the subtype is ignored during the match. 
     * For example, this method will return <code>true</code> when 
     * comparing the ContentType for <strong>"text/plain"</strong> 
     * with <strong>"text/*" </strong>
     *
     * @param   s   the content-type string to match
     * @return   true if it matches
     */
    public boolean match(String s) {
        try {
            return match(new ContentType(s));
        } catch (ParseException pex) {
            return false;
        }
    }
}