# Variable.java

    /*
    *  Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
    *
    *  WSO2 Inc. 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.apache.synapse.commons.templates.uri.parser;

    import org.apache.synapse.commons.templates.uri.URITemplateException;

    public class Variable {

        private String name;
        private int prefix = -1;

        public Variable(String value) throws URITemplateException {
            this.name = value;
            for (int i = 0; i < value.length(); i++) {
                char ch = value.charAt(i);
                if (!isValid(value.charAt(i)) && ch != ':') {
                    throw new URITemplateException("Invalid character: '" + ch + "' in expression");
                } else if (ch == ':') {
                    this.name = value.substring(0, i);
                    this.prefix = Integer.parseInt(value.substring(i + 1));
                    if (prefix <= 0) {
                        throw new URITemplateException("Invalid variable prefix: " + prefix);
                    }
                    break;
                }
            }
        }

        private boolean isValid(char ch) {
            return ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') ||
                    (ch >= '0' && ch <= '9') || ch == '.'  || ch == '-' || ch == '_');
        }

        public String getName() {
            return name;
        }

        public String modify(String value) {
            if (prefix > 0 && prefix < value.length()) {
                return value.substring(0, prefix);
            }
            return value;
        }

        public boolean checkModifier(String value) {
            if (prefix > 0) {
                return value.length() == prefix;
            }
            return true;
        }
    }