001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.console.filter; 018 019import java.util.ArrayList; 020import java.util.Iterator; 021import java.util.List; 022 023public abstract class ResultTransformFilter implements QueryFilter { 024 private QueryFilter next; 025 026 /** 027 * Constructs a query filter that transform the format of the query result 028 * 029 * @param next - the query filter to retrieve the results from 030 */ 031 protected ResultTransformFilter(QueryFilter next) { 032 this.next = next; 033 } 034 035 /** 036 * Transforms the queried results to a collection of different objects 037 * 038 * @param query - the query string 039 * @return collections of transformed objects 040 * @throws Exception 041 */ 042 public List query(String query) throws Exception { 043 return transformList(next.query(query)); 044 } 045 046 /** 047 * Transforms the queried results to a collection of different objects 048 * 049 * @param queries - the query map 050 * @return collections of transformed objects 051 * @throws Exception 052 */ 053 public List<Object> query(List queries) throws Exception { 054 return transformList(next.query(queries)); 055 } 056 057 /** 058 * Transforms a collection to a collection of different objects. 059 * 060 * @param result - the collection to transform 061 * @return collection of properties objects 062 */ 063 protected List<Object> transformList(List<Object> result) throws Exception { 064 List<Object> props = new ArrayList<Object>(); 065 066 for (Iterator<Object> i = result.iterator(); i.hasNext();) { 067 props.add(transformElement(i.next())); 068 } 069 070 return props; 071 } 072 073 /** 074 * Transform a result object 075 * 076 * @param obj - the object instance to transform 077 * @return the transformed object 078 */ 079 protected abstract Object transformElement(Object obj) throws Exception; 080 081}