item.java

DSPACE的源码 dspace-1.4-source

    {
        Collection myCollection = null;

        // get the collection ID
        int cid = itemRow.getIntColumn("owning_collection");

        myCollection = Collection.find(ourContext, cid);

        return myCollection;
    }

    /**
     * Get Dublin Core metadata for the item.
     * Passing in a <code>null</code> value for <code>qualifier</code>
     * or <code>lang</code> only matches Dublin Core fields where that
     * qualifier or languages is actually <code>null</code>.
     * Passing in <code>Item.ANY</code>
     * retrieves all metadata fields with any value for the qualifier or
     * language, including <code>null</code>
     * <P>
     * Examples:
     * <P>
     * Return values of the unqualified "title" field, in any language.
     * Qualified title fields (e.g. "title.uniform") are NOT returned:
     * <P>
     * <code>item.getDC( "title", null, Item.ANY );</code>
     * <P>
     * Return all US English values of the "title" element, with any qualifier
     * (including unqualified):
     * <P>
     * <code>item.getDC( "title", Item.ANY, "en_US" );</code>
     * <P>
     * The ordering of values of a particular element/qualifier/language
     * combination is significant. When retrieving with wildcards, values of a
     * particular element/qualifier/language combinations will be adjacent, but
     * the overall ordering of the combinations is indeterminate.
     * 
     * @param element
     *            the Dublin Core element. <code>Item.ANY</code> matches any
     *            element. <code>null</code> doesn't really make sense as all
     *            DC must have an element.
     * @param qualifier
     *            the qualifier. <code>null</code> means unqualified, and
     *            <code>Item.ANY</code> means any qualifier (including
     *            unqualified.)
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means only
     *            values with no language are returned, and
     *            <code>Item.ANY</code> means values with any country code or
     *            no country code are returned.
     * @return Dublin Core fields that match the parameters
     */
    public DCValue[] getDC(String element, String qualifier, String lang)
    {
        return getMetadata(MetadataSchema.DC_SCHEMA, element, qualifier, lang);
    }

    /**
     * Get metadata for the item in a chosen schema.
     * See <code>MetadataSchema</code> for more information about schemas.
     * Passing in a <code>null</code> value for <code>qualifier</code>
     * or <code>lang</code> only matches metadata fields where that
     * qualifier or languages is actually <code>null</code>.
     * Passing in <code>Item.ANY</code>
     * retrieves all metadata fields with any value for the qualifier or
     * language, including <code>null</code>
     * <P>
     * Examples:
     * <P>
     * Return values of the unqualified "title" field, in any language.
     * Qualified title fields (e.g. "title.uniform") are NOT returned:
     * <P>
     * <code>item.getMetadata("dc", "title", null, Item.ANY );</code>
     * <P>
     * Return all US English values of the "title" element, with any qualifier
     * (including unqualified):
     * <P>
     * <code>item.getMetadata("dc, "title", Item.ANY, "en_US" );</code>
     * <P>
     * The ordering of values of a particular element/qualifier/language
     * combination is significant. When retrieving with wildcards, values of a
     * particular element/qualifier/language combinations will be adjacent, but
     * the overall ordering of the combinations is indeterminate.
     *
     * @param schema
     *            the schema for the metadata field. <em>Must</em> match
     *            the <code>name</code> of an existing metadata schema.
     * @param element
     *            the element name. <code>Item.ANY</code> matches any
     *            element. <code>null</code> doesn't really make sense as all
     *            metadata must have an element.
     * @param qualifier
     *            the qualifier. <code>null</code> means unqualified, and
     *            <code>Item.ANY</code> means any qualifier (including
     *            unqualified.)
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means only
     *            values with no language are returned, and
     *            <code>Item.ANY</code> means values with any country code or
     *            no country code are returned.
     * @return metadata fields that match the parameters
     */
    public DCValue[] getMetadata(String schema, String element, String qualifier,
            String lang)
    {
        // Build up list of matching values
        List values = new ArrayList();
        Iterator i = dublinCore.iterator();

        while (i.hasNext())
        {
            DCValue dcv = (DCValue) i.next();

            if (match(schema, element, qualifier, lang, dcv))
            {
                // We will return a copy of the object in case it is altered
                DCValue copy = new DCValue();
                copy.element = dcv.element;
                copy.qualifier = dcv.qualifier;
                copy.value = dcv.value;
                copy.language = dcv.language;
                copy.schema = dcv.schema;

                values.add(copy);
            }
        }

        // Create an array of matching values
        DCValue[] valueArray = new DCValue[values.size()];
        valueArray = (DCValue[]) values.toArray(valueArray);

        return valueArray;
    }

    /**
     * Add Dublin Core metadata fields. These are appended to existing values.
     * Use <code>clearDC</code> to remove values. The ordering of values
     * passed in is maintained.
     * 
     * @param element
     *            the Dublin Core element
     * @param qualifier
     *            the Dublin Core qualifer, or <code>null</code> for
     *            unqualified
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means the
     *            value has no language (for example, a date).
     * @param values
     *            the values to add.
     */
    public void addDC(String element, String qualifier, String lang,
            String[] values)
    {
        addMetadata(MetadataSchema.DC_SCHEMA, element, qualifier, lang, values);
    }

    /**
     * Add a single Dublin Core metadata field. This is appended to existing
     * values. Use <code>clearDC</code> to remove values.
     *
     * @param element
     *            the Dublin Core element
     * @param qualifier
     *            the Dublin Core qualifer, or <code>null</code> for
     *            unqualified
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means the
     *            value has no language (for example, a date).
     * @param value
     *            the value to add.
     */
    public void addDC(String element, String qualifier, String lang,
            String value)
    {
        addMetadata(MetadataSchema.DC_SCHEMA, element, qualifier, lang, value);
    }
    
    /**
     * Add metadata fields. These are appended to existing values.
     * Use <code>clearDC</code> to remove values. The ordering of values
     * passed in is maintained.
     * @param schema
     *            the schema for the metadata field. <em>Must</em> match
     *            the <code>name</code> of an existing metadata schema.
     * @param element
     *            the metadata element name
     * @param qualifier
     *            the metadata qualifer name, or <code>null</code> for
     *            unqualified
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means the
     *            value has no language (for example, a date).
     * @param values
     *            the values to add.
     */
    public void addMetadata(String schema, String element, String qualifier, String lang,
            String[] values)
    {
        // We will not verify that they are valid entries in the registry
        // until update() is called.
        for (int i = 0; i < values.length; i++)
        {
            DCValue dcv = new DCValue();
            dcv.schema = schema;
            dcv.element = element;
            dcv.qualifier = qualifier;
            dcv.language = lang;
            dcv.value = (values[i] == null ? null : values[i].trim());
            dublinCore.add(dcv);
        }

        if (values.length > 0)
        {
            dublinCoreChanged = true;
        }
    }

    /**
     * Add a single metadata field. This is appended to existing
     * values. Use <code>clearDC</code> to remove values.
     * 
     * @param schema
     *            the schema for the metadata field. <em>Must</em> match
     *            the <code>name</code> of an existing metadata schema.
     * @param element
     *            the metadata element name
     * @param qualifier
     *            the metadata qualifer, or <code>null</code> for
     *            unqualified
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means the
     *            value has no language (for example, a date).
     * @param value
     *            the value to add.
     */
    public void addMetadata(String schema, String element, String qualifier,
            String lang, String value)
    {
        String[] valArray = new String[1];
        valArray[0] = value;

        addMetadata(schema, element, qualifier, lang, valArray);
    }

    /**
     * Clear Dublin Core metadata values. As with <code>getDC</code> above,
     * passing in <code>null</code> only matches fields where the qualifier or
     * language is actually <code>null</code>.<code>Item.ANY</code> will
     * match any element, qualifier or language, including <code>null</code>.
     * Thus, <code>item.clearDC(Item.ANY, Item.ANY, Item.ANY)</code> will
     * remove all Dublin Core metadata associated with an item.
     * 
     * @param element
     *            the Dublin Core element to remove, or <code>Item.ANY</code>
     * @param qualifier
     *            the qualifier. <code>null</code> means unqualified, and
     *            <code>Item.ANY</code> means any qualifier (including
     *            unqualified.)
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means only
     *            values with no language are removed, and <code>Item.ANY</code>
     *            means values with any country code or no country code are
     *            removed.
     */
    public void clearDC(String element, String qualifier, String lang)
    {
        clearMetadata(MetadataSchema.DC_SCHEMA, element, qualifier, lang);
    }

    /**
     * Clear metadata values. As with <code>getDC</code> above,
     * passing in <code>null</code> only matches fields where the qualifier or
     * language is actually <code>null</code>.<code>Item.ANY</code> will
     * match any element, qualifier or language, including <code>null</code>.
     * Thus, <code>item.clearDC(Item.ANY, Item.ANY, Item.ANY)</code> will
     * remove all Dublin Core metadata associated with an item.
     *
     * @param schema
     *            the schema for the metadata field. <em>Must</em> match
     *            the <code>name</code> of an existing metadata schema.
     * @param element
     *            the Dublin Core element to remove, or <code>Item.ANY</code>
     * @param qualifier
     *            the qualifier. <code>null</code> means unqualified, and
     *            <code>Item.ANY</code> means any qualifier (including
     *            unqualified.)
     * @param lang
     *            the ISO639 language code, optionally followed by an underscore
     *            and the ISO3166 country code. <code>null</code> means only
     *            values with no language are removed, and <code>Item.ANY</code>
     *            means values with any country code or no country code are
     *            removed.
     */
    public void clearMetadata(String schema, String element, String qualifier,
            String lang)
    {
        // We will build a list of values NOT matching the values to clear
        List values = new ArrayList();
        Iterator i = dublinCore.iterator();

        while (i.hasNext())
        {
            DCValue dcv = (DCValue) i.next();

            if (!match(schema, element, qualifier, lang, dcv))
            {
                values.add(dcv);
            }
        }

        // Now swap the old list of values for the new, unremoved values
        dublinCore = values;
        dublinCoreChanged = true;
    }

    /**
     * Utility method for pattern-matching metadata elements.  This
     * method will return <code>true</code> if the given schema,
     * element, qualifier and language match the schema, element,
     * qualifier and language of the <code>DCValue</code> object passed
     * in.  Any or all of the elemenent, qualifier and language passed
     * in can be the <code>Item.ANY</code> wildcard.
     *
     * @param schema
     *            the schema for the metadata field. <em>Must</em> match
     *            the <code>name</code> of an existing metadata schema.
     * @param element
     *            the element to match, or <code>Item.ANY</code>
     * @param qualifier
     *            the qualifier to match, or <code>Item.ANY</code>
     * @param language
     *            the language to match, or <code>Item.ANY</code>
     * @param dcv
     *            the Dublin Core value
     * @return <code>true</code> if there is a match
     */
    private boolean match(String schema, String element, String qualifier,
            String language, DCValue dcv)
    {
        // We will attempt to disprove a match - if we can't we have a match
        if (!element.equals(Item.ANY) && !element.equals(dcv.element))
        {
            // Elements do not match, no wildcard
            return false;
        }

        if (qualifier == null)
        {
            // Value must be unqualified
            if (dcv.qualifier != null)
            {
                // Value is qualified, so no match
                return false;
            }
        }
        else if (!qualifier.equals(Item.ANY))
        {
            // Not a wildcard, so qualifier must match exactly
            if (!qualifier.equals(dcv.qualifier))
            {
                return false;
            }
        }

        if (language == null)
        {
            // Value must be null language to match
            if (dcv.language != null)
            {
                // Value is qualified, so no match
                return false;
            }
        }
        else if (!language.equals(Item.ANY))
        {
            // Not a wildcard, so language must match exactly
            if (!language.equals(dcv.language))
            {