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 */ 017 package org.apache.activemq.console.filter; 018 019 import java.util.ArrayList; 020 import java.util.Collection; 021 import java.util.HashMap; 022 import java.util.Iterator; 023 import java.util.List; 024 import java.util.Map; 025 import java.util.Set; 026 027 public class PropertiesViewFilter implements QueryFilter { 028 protected QueryFilter next; 029 protected Set viewFilter; 030 031 /** 032 * Creates a filter that will select the properties of a map object to view 033 * 034 * @param next - the next query filter that will return a collection of maps 035 */ 036 public PropertiesViewFilter(QueryFilter next) { 037 this(null, next); 038 } 039 040 /** 041 * Creates a filter that will select the properties of a map object to view 042 * 043 * @param viewFilter - the properties to view 044 * @param next - the next query filter that will return a collection of maps 045 */ 046 public PropertiesViewFilter(Set viewFilter, QueryFilter next) { 047 this.next = next; 048 this.viewFilter = viewFilter; 049 } 050 051 /** 052 * Filter the properties to view of the query result 053 * 054 * @param query - the query string 055 * @return list of objects that has been view filtered 056 */ 057 public List<Map<Object, Object>> query(String query) throws Exception { 058 return filterViewCollection(next.query(query), viewFilter); 059 } 060 061 /** 062 * Filter the properties to view of the query result 063 * 064 * @param queries - the query map 065 * @return list of objects that has been view filtered 066 * @throws Exception 067 */ 068 public List<Map<Object, Object>> query(List queries) throws Exception { 069 return filterViewCollection(next.query(queries), viewFilter); 070 } 071 072 /** 073 * Filter the view of each element in the collection 074 * 075 * @param result - the lists to filter the view from 076 * @param viewFilter - the views to select 077 * @return list of objects whose view has been filtered 078 */ 079 protected List<Map<Object, Object>> filterViewCollection(Collection<Map<Object, Object>> result, Set viewFilter) { 080 // Use a list to allow duplicate entries 081 List<Map<Object, Object>> newCollection = new ArrayList<Map<Object, Object>>(); 082 083 for (Iterator<Map<Object, Object>> i = result.iterator(); i.hasNext();) { 084 newCollection.add(filterView(i.next())); 085 } 086 087 return newCollection; 088 } 089 090 /** 091 * Select only the attributes to view from the map data 092 * 093 * @param data - data to filter the view from 094 * @return - data with the view filtered 095 */ 096 protected Map<Object, Object> filterView(Map<Object, Object> data) { 097 // If no view specified, display all attributes 098 if (viewFilter == null || viewFilter.isEmpty()) { 099 return data; 100 } 101 102 Map<Object, Object> newData; 103 try { 104 // Lets try to use the same class as the original 105 newData = data.getClass().newInstance(); 106 } catch (Exception e) { 107 // Lets use a default HashMap 108 newData = new HashMap<Object, Object>(); 109 } 110 111 // Filter the keys to view 112 for (Iterator i = viewFilter.iterator(); i.hasNext();) { 113 Object key = i.next(); 114 Object val = data.get(key); 115 116 if (val != null) { 117 newData.put(key, val); 118 } 119 } 120 121 return newData; 122 } 123 124 }