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.*; 020 021public class PropertiesViewFilter implements QueryFilter { 022 protected QueryFilter next; 023 protected Set viewFilter; 024 025 /** 026 * Creates a filter that will select the properties of a map object to view 027 * 028 * @param next - the next query filter that will return a collection of maps 029 */ 030 public PropertiesViewFilter(QueryFilter next) { 031 this(null, next); 032 } 033 034 /** 035 * Creates a filter that will select the properties of a map object to view 036 * 037 * @param viewFilter - the properties to view 038 * @param next - the next query filter that will return a collection of maps 039 */ 040 public PropertiesViewFilter(Set viewFilter, QueryFilter next) { 041 this.next = next; 042 this.viewFilter = viewFilter; 043 } 044 045 /** 046 * Filter the properties to view of the query result 047 * 048 * @param query - the query string 049 * @return list of objects that has been view filtered 050 */ 051 public List<Map<Object, Object>> query(String query) throws Exception { 052 return filterViewCollection(next.query(query), viewFilter); 053 } 054 055 /** 056 * Filter the properties to view of the query result 057 * 058 * @param queries - the query map 059 * @return list of objects that has been view filtered 060 * @throws Exception 061 */ 062 public List<Map<Object, Object>> query(List queries) throws Exception { 063 return filterViewCollection(next.query(queries), viewFilter); 064 } 065 066 /** 067 * Filter the view of each element in the collection 068 * 069 * @param result - the lists to filter the view from 070 * @param viewFilter - the views to select 071 * @return list of objects whose view has been filtered 072 */ 073 protected List<Map<Object, Object>> filterViewCollection(Collection<Map<Object, Object>> result, Set viewFilter) { 074 // Use a list to allow duplicate entries 075 List<Map<Object, Object>> newCollection = new ArrayList<Map<Object, Object>>(); 076 077 for (Iterator<Map<Object, Object>> i = result.iterator(); i.hasNext();) { 078 newCollection.add(filterView(i.next())); 079 } 080 081 return newCollection; 082 } 083 084 /** 085 * Select only the attributes to view from the map data 086 * 087 * @param data - data to filter the view from 088 * @return - data with the view filtered 089 */ 090 protected Map<Object, Object> filterView(Map<Object, Object> data) { 091 // If no view specified, display all attributes 092 if (viewFilter == null || viewFilter.isEmpty()) { 093 return data; 094 } 095 096 Map<Object, Object> newData; 097 try { 098 // Lets try to use the same class as the original 099 newData = new LinkedHashMap(data.getClass().newInstance()); 100 } catch (Exception e) { 101 // Lets use a default HashMap 102 newData = new LinkedHashMap<Object, Object>(); 103 } 104 105 // Filter the keys to view 106 for (Iterator i = viewFilter.iterator(); i.hasNext();) { 107 Object key = i.next(); 108 Object val = data.get(key); 109 110 if (val != null) { 111 newData.put(key, val); 112 } 113 } 114 115 return newData; 116 } 117 118}