org.wicketstuff.rest.resource.urlsegments.AbstractURLSegment.java Source code

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Here is the source code for org.wicketstuff.rest.resource.urlsegments.AbstractURLSegment.java

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/**
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.wicketstuff.rest.resource.urlsegments;

import static org.apache.wicket.util.parse.metapattern.MetaPattern.COLON;
import static org.apache.wicket.util.parse.metapattern.MetaPattern.LEFT_CURLY;
import static org.apache.wicket.util.parse.metapattern.MetaPattern.RIGHT_CURLY;
import static org.apache.wicket.util.parse.metapattern.MetaPattern.VARIABLE_NAME;

import java.util.HashMap;
import java.util.Map;

import org.apache.wicket.util.parse.metapattern.MetaPattern;
import org.apache.wicket.util.parse.metapattern.OptionalMetaPattern;
import org.apache.wicket.util.parse.metapattern.parsers.VariableAssignmentParser;
import org.apache.wicket.util.string.StringValue;
import org.wicketstuff.rest.resource.urlsegments.visitor.ISegementElement;

/**
 * Base class to contain the informations of the segments that compose the URL used to map a method.
 * It's used to use simple segments with no path parameters.
 * 
 * @author andrea del bene
 * 
 */
public abstract class AbstractURLSegment extends StringValue implements ISegementElement {
    private static final long serialVersionUID = 1L;

    /** MetaPattern to identify the content of a regular expression. */
    public static final MetaPattern REGEXP_BODY = new MetaPattern("([^\\}\\{]*|(\\{[\\d]+\\}))*");
    /** MetaPattern to identify the declaration of a regular expression. */
    public static final MetaPattern REGEXP_DECLARATION = new MetaPattern(COLON, REGEXP_BODY);
    /**
     * MetaPattern to identify a path parameter inside a segment (i.e. "{paramName:regexp}")
     */
    public static final MetaPattern SEGMENT_PARAMETER = new MetaPattern(LEFT_CURLY, VARIABLE_NAME,
            new OptionalMetaPattern(REGEXP_DECLARATION), RIGHT_CURLY);

    /** The MetaPattern (i.e regular expression) corresponding to the current segment. */
    private final MetaPattern metaPattern;

    AbstractURLSegment(String text) {
        super(text);
        this.metaPattern = loadMetaPattern();
    }

    /**
     * Method invoked to load the MetaPattern for the current segment.
     * 
     * @return the MetaPattern for the current segment.
     */
    protected abstract MetaPattern loadMetaPattern();

    /**
     * Factory method to create new instances of AbstractURLSegment.
     * 
     * @param segment
     *            The content of the new segment.
     * @return the new instance of AbstractURLSegment.
     */
    static public AbstractURLSegment newSegment(String segment) {
        if (SEGMENT_PARAMETER.matcher(segment).matches())
            return new ParamSegment(segment);

        if (SEGMENT_PARAMETER.matcher(segment).find())
            return new MultiParamSegment(segment);

        return new FixedURLSegment(segment);
    }

    /**
     * Get the segment value without optional matrix parameters. For example given the following
     * value 'segment;parm=value', the function returns 'segment'.
     * 
     * @param fullSegment
     * @return the value of the segment without matrix parameters.
     */
    static public String getActualSegment(String fullSegment) {
        String[] segmentParts = fullSegment.split(MetaPattern.SEMICOLON.toString());
        return segmentParts[0];
    }

    /**
     * Extract matrix parameters from the segment in input.
     * 
     * @param fullSegment
     *            the segment in input.
     * @return a map containing matrix parameters.
     */
    static public Map<String, String> getSegmentMatrixParameters(String fullSegment) {
        String[] segmentParts = fullSegment.split(MetaPattern.SEMICOLON.toString());
        HashMap<String, String> matrixParameters = new HashMap<String, String>();

        if (segmentParts.length < 2)
            return matrixParameters;

        for (int i = 1; i < segmentParts.length; i++) {
            String parameterDeclar = segmentParts[i];
            VariableAssignmentParser parser = new VariableAssignmentParser(parameterDeclar);

            parser.matcher().find();
            matrixParameters.put(parser.getKey(), parser.getValue());
        }

        return matrixParameters;
    }

    /**
     * Getter method for segment MetaPattern.
     **/
    public final MetaPattern getMetaPattern() {
        return metaPattern;
    }
}