alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (MimeType.java)

This example Java source code file (MimeType.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

classnotfoundexception, cloneable, clonenotsupportedexception, ioexception, mimetype, mimetypeparameterlist, mimetypeparseexception, object, primary, string, sub, tspecials, unable, utf, util

The MimeType.java Java example source code

/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.awt.datatransfer;

import java.io.Externalizable;
import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Locale;


/**
 * A Multipurpose Internet Mail Extension (MIME) type, as defined
 * in RFC 2045 and 2046.
 *
 * THIS IS *NOT* - REPEAT *NOT* - A PUBLIC CLASS! DataFlavor IS
 * THE PUBLIC INTERFACE, AND THIS IS PROVIDED AS A ***PRIVATE***
 * (THAT IS AS IN *NOT* PUBLIC) HELPER CLASS!
 */
class MimeType implements Externalizable, Cloneable {

    /*
     * serialization support
     */

    static final long serialVersionUID = -6568722458793895906L;

    /**
     * Constructor for externalization; this constructor should not be
     * called directly by an application, since the result will be an
     * uninitialized, immutable <code>MimeType object.
     */
    public MimeType() {
    }

    /**
     * Builds a <code>MimeType from a String.
     *
     * @param rawdata text used to initialize the <code>MimeType
     * @throws NullPointerException if <code>rawdata is null
     */
    public MimeType(String rawdata) throws MimeTypeParseException {
        parse(rawdata);
    }

    /**
     * Builds a <code>MimeType with the given primary and sub
     * type but has an empty parameter list.
     *
     * @param primary the primary type of this <code>MimeType
     * @param sub the subtype of this <code>MimeType
     * @throws NullPointerException if either <code>primary or
     *         <code>sub is null
     */
    public MimeType(String primary, String sub) throws MimeTypeParseException {
        this(primary, sub, new MimeTypeParameterList());
    }

    /**
     * Builds a <code>MimeType with a pre-defined
     * and valid (or empty) parameter list.
     *
     * @param primary the primary type of this <code>MimeType
     * @param sub the subtype of this <code>MimeType
     * @param mtpl the requested parameter list
     * @throws NullPointerException if either <code>primary,
     *         <code>sub or mtpl is null
     */
    public MimeType(String primary, String sub, MimeTypeParameterList mtpl) throws
MimeTypeParseException {
        //    check to see if primary is valid
        if(isValidToken(primary)) {
            primaryType = primary.toLowerCase(Locale.ENGLISH);
        } else {
            throw new MimeTypeParseException("Primary type is invalid.");
        }

        //    check to see if sub is valid
        if(isValidToken(sub)) {
            subType = sub.toLowerCase(Locale.ENGLISH);
        } else {
            throw new MimeTypeParseException("Sub type is invalid.");
        }

        parameters = (MimeTypeParameterList)mtpl.clone();
    }

    public int hashCode() {

        // We sum up the hash codes for all of the strings. This
        // way, the order of the strings is irrelevant
        int code = 0;
        code += primaryType.hashCode();
        code += subType.hashCode();
        code += parameters.hashCode();
        return code;
    } // hashCode()

    /**
     * <code>MimeTypes are equal if their primary types,
     * subtypes, and  parameters are all equal. No default values
     * are taken into account.
     * @param thatObject the object to be evaluated as a
     *    <code>MimeType
     * @return <code>true if thatObject is
     *    a <code>MimeType; otherwise returns false
     */
    public boolean equals(Object thatObject) {
        if (!(thatObject instanceof MimeType)) {
            return false;
        }
        MimeType that = (MimeType)thatObject;
        boolean isIt =
            ((this.primaryType.equals(that.primaryType)) &&
             (this.subType.equals(that.subType)) &&
             (this.parameters.equals(that.parameters)));
        return isIt;
    } // equals()

    /**
     * A routine for parsing the MIME type out of a String.
     *
     * @throws NullPointerException if <code>rawdata is null
     */
    private void parse(String rawdata) throws MimeTypeParseException {
        int slashIndex = rawdata.indexOf('/');
        int semIndex = rawdata.indexOf(';');
        if((slashIndex < 0) && (semIndex < 0)) {
            //    neither character is present, so treat it
            //    as an error
            throw new MimeTypeParseException("Unable to find a sub type.");
        } else if((slashIndex < 0) && (semIndex >= 0)) {
            //    we have a ';' (and therefore a parameter list),
            //    but no '/' indicating a sub type is present
            throw new MimeTypeParseException("Unable to find a sub type.");
        } else if((slashIndex >= 0) && (semIndex < 0)) {
            //    we have a primary and sub type but no parameter list
            primaryType = rawdata.substring(0,slashIndex).
                trim().toLowerCase(Locale.ENGLISH);
            subType = rawdata.substring(slashIndex + 1).
                trim().toLowerCase(Locale.ENGLISH);
            parameters = new MimeTypeParameterList();
        } else if (slashIndex < semIndex) {
            //    we have all three items in the proper sequence
            primaryType = rawdata.substring(0, slashIndex).
                trim().toLowerCase(Locale.ENGLISH);
            subType = rawdata.substring(slashIndex + 1,
                semIndex).trim().toLowerCase(Locale.ENGLISH);
            parameters = new
MimeTypeParameterList(rawdata.substring(semIndex));
        } else {
            //    we have a ';' lexically before a '/' which means we have a primary type
            //    & a parameter list but no sub type
            throw new MimeTypeParseException("Unable to find a sub type.");
        }

        //    now validate the primary and sub types

        //    check to see if primary is valid
        if(!isValidToken(primaryType)) {
            throw new MimeTypeParseException("Primary type is invalid.");
        }

        //    check to see if sub is valid
        if(!isValidToken(subType)) {
            throw new MimeTypeParseException("Sub type is invalid.");
        }
    }

    /**
     * Retrieve the primary type of this object.
     */
    public String getPrimaryType() {
        return primaryType;
    }

    /**
     * Retrieve the sub type of this object.
     */
    public String getSubType() {
        return subType;
    }

    /**
     * Retrieve a copy of this object's parameter list.
     */
    public MimeTypeParameterList getParameters() {
        return (MimeTypeParameterList)parameters.clone();
    }

    /**
     * Retrieve the value associated with the given name, or null if there
     * is no current association.
     */
    public String getParameter(String name) {
        return parameters.get(name);
    }

    /**
     * Set the value to be associated with the given name, replacing
     * any previous association.
     *
     * @throw IllegalArgumentException if parameter or value is illegal
     */
    public void setParameter(String name, String value) {
        parameters.set(name, value);
    }

    /**
     * Remove any value associated with the given name.
     *
     * @throw IllegalArgumentExcpetion if parameter may not be deleted
     */
    public void removeParameter(String name) {
        parameters.remove(name);
    }

    /**
     * Return the String representation of this object.
     */
    public String toString() {
        return getBaseType() + parameters.toString();
    }

    /**
     * Return a String representation of this object
     * without the parameter list.
     */
    public String getBaseType() {
        return primaryType + "/" + subType;
    }

    /**
     * Returns <code>true if the primary type and the
     * subtype of this object are the same as the specified
     * <code>type; otherwise returns false.
     *
     * @param type the type to compare to <code>this's type
     * @return <code>true if the primary type and the
     *    subtype of this object are the same as the
     *    specified <code>type; otherwise returns
     *    <code>false
     */
    public boolean match(MimeType type) {
        if (type == null)
            return false;
        return primaryType.equals(type.getPrimaryType())
                    && (subType.equals("*")
                            || type.getSubType().equals("*")
                            || (subType.equals(type.getSubType())));
    }

    /**
     * Returns <code>true if the primary type and the
     * subtype of this object are the same as the content type
     * described in <code>rawdata; otherwise returns
     * <code>false.
     *
     * @param rawdata the raw data to be examined
     * @return <code>true if the primary type and the
     *    subtype of this object are the same as the content type
     *    described in <code>rawdata; otherwise returns
     *    <code>false; if rawdata is
     *    <code>null, returns false
     */
    public boolean match(String rawdata) throws MimeTypeParseException {
        if (rawdata == null)
            return false;
        return match(new MimeType(rawdata));
    }

    /**
     * The object implements the writeExternal method to save its contents
     * by calling the methods of DataOutput for its primitive values or
     * calling the writeObject method of ObjectOutput for objects, strings
     * and arrays.
     * @exception IOException Includes any I/O exceptions that may occur
     */
    public void writeExternal(ObjectOutput out) throws IOException {
        String s = toString(); // contains ASCII chars only
        // one-to-one correspondence between ASCII char and byte in UTF string
        if (s.length() <= 65535) { // 65535 is max length of UTF string
            out.writeUTF(s);
        } else {
            out.writeByte(0);
            out.writeByte(0);
            out.writeInt(s.length());
            out.write(s.getBytes());
        }
    }

    /**
     * The object implements the readExternal method to restore its
     * contents by calling the methods of DataInput for primitive
     * types and readObject for objects, strings and arrays.  The
     * readExternal method must read the values in the same sequence
     * and with the same types as were written by writeExternal.
     * @exception ClassNotFoundException If the class for an object being
     *              restored cannot be found.
     */
    public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
        String s = in.readUTF();
        if (s == null || s.length() == 0) { // long mime type
            byte[] ba = new byte[in.readInt()];
            in.readFully(ba);
            s = new String(ba);
        }
        try {
            parse(s);
        } catch(MimeTypeParseException e) {
            throw new IOException(e.toString());
        }
    }

    /**
     * Returns a clone of this object.
     * @return a clone of this object
     */

    public Object clone() {
        MimeType newObj = null;
        try {
            newObj = (MimeType)super.clone();
        } catch (CloneNotSupportedException cannotHappen) {
        }
        newObj.parameters = (MimeTypeParameterList)parameters.clone();
        return newObj;
    }

    private String    primaryType;
    private String    subType;
    private MimeTypeParameterList parameters;

    //    below here be scary parsing related things

    /**
     * Determines whether or not a given character belongs to a legal token.
     */
    private static boolean isTokenChar(char c) {
        return ((c > 040) && (c < 0177)) && (TSPECIALS.indexOf(c) < 0);
    }

    /**
     * Determines whether or not a given string is a legal token.
     *
     * @throws NullPointerException if <code>s is null
     */
    private boolean isValidToken(String s) {
        int len = s.length();
        if(len > 0) {
            for (int i = 0; i < len; ++i) {
                char c = s.charAt(i);
                if (!isTokenChar(c)) {
                    return false;
                }
            }
            return true;
        } else {
            return false;
        }
    }

    /**
     * A string that holds all the special chars.
     */

    private static final String TSPECIALS = "()<>@,;:\\\"/[]?=";

} // class MimeType

Other Java examples (source code examples)

Here is a short list of links related to this Java MimeType.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.