Coverage Report - org.apache.commons.lang3.text.StrLookup
 
Classes in this File Line Coverage Branch Coverage Complexity
StrLookup
100%
7/7
N/A
1,875
StrLookup$1
N/A
N/A
1,875
StrLookup$MapStrLookup
100%
9/9
100%
4/4
1,875
StrLookup$SystemPropertiesStrLookup
80%
4/5
100%
2/2
1,875
 
 1  
 /*
 2  
  * Licensed to the Apache Software Foundation (ASF) under one or more
 3  
  * contributor license agreements.  See the NOTICE file distributed with
 4  
  * this work for additional information regarding copyright ownership.
 5  
  * The ASF licenses this file to You under the Apache License, Version 2.0
 6  
  * (the "License"); you may not use this file except in compliance with
 7  
  * the License.  You may obtain a copy of the License at
 8  
  *
 9  
  *      http://www.apache.org/licenses/LICENSE-2.0
 10  
  *
 11  
  * Unless required by applicable law or agreed to in writing, software
 12  
  * distributed under the License is distributed on an "AS IS" BASIS,
 13  
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 14  
  * See the License for the specific language governing permissions and
 15  
  * limitations under the License.
 16  
  */
 17  
 package org.apache.commons.lang3.text;
 18  
 
 19  
 import java.util.Map;
 20  
 
 21  
 /**
 22  
  * Lookup a String key to a String value.
 23  
  * <p>
 24  
  * This class represents the simplest form of a string to string map.
 25  
  * It has a benefit over a map in that it can create the result on
 26  
  * demand based on the key.
 27  
  * <p>
 28  
  * This class comes complete with various factory methods.
 29  
  * If these do not suffice, you can subclass and implement your own matcher.
 30  
  * <p>
 31  
  * For example, it would be possible to implement a lookup that used the
 32  
  * key as a primary key, and looked up the value on demand from the database
 33  
  *
 34  
  * @since 2.2
 35  
  * @deprecated as of 3.6, use commons-text
 36  
  * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StrLookup.html">
 37  
  * StrLookup</a> instead
 38  
  */
 39  
 @Deprecated
 40  
 public abstract class StrLookup<V> {
 41  
 
 42  
     /**
 43  
      * Lookup that always returns null.
 44  
      */
 45  1
     private static final StrLookup<String> NONE_LOOKUP = new MapStrLookup<>(null);
 46  
 
 47  
     /**
 48  
      * Lookup based on system properties.
 49  
      */
 50  1
     private static final StrLookup<String> SYSTEM_PROPERTIES_LOOKUP = new SystemPropertiesStrLookup();
 51  
 
 52  
     //-----------------------------------------------------------------------
 53  
     /**
 54  
      * Returns a lookup which always returns null.
 55  
      *
 56  
      * @return a lookup that always returns null, not null
 57  
      */
 58  
     public static StrLookup<?> noneLookup() {
 59  3
         return NONE_LOOKUP;
 60  
     }
 61  
 
 62  
     /**
 63  
      * Returns a new lookup which uses a copy of the current
 64  
      * {@link System#getProperties() System properties}.
 65  
      * <p>
 66  
      * If a security manager blocked access to system properties, then null will
 67  
      * be returned from every lookup.
 68  
      * <p>
 69  
      * If a null key is used, this lookup will throw a NullPointerException.
 70  
      *
 71  
      * @return a lookup using system properties, not null
 72  
      */
 73  
     public static StrLookup<String> systemPropertiesLookup() {
 74  8
         return SYSTEM_PROPERTIES_LOOKUP;
 75  
     }
 76  
 
 77  
     /**
 78  
      * Returns a lookup which looks up values using a map.
 79  
      * <p>
 80  
      * If the map is null, then null will be returned from every lookup.
 81  
      * The map result object is converted to a string using toString().
 82  
      *
 83  
      * @param <V> the type of the values supported by the lookup
 84  
      * @param map  the map of keys to values, may be null
 85  
      * @return a lookup using the map, not null
 86  
      */
 87  
     public static <V> StrLookup<V> mapLookup(final Map<String, V> map) {
 88  70
         return new MapStrLookup<>(map);
 89  
     }
 90  
 
 91  
     //-----------------------------------------------------------------------
 92  
     /**
 93  
      * Constructor.
 94  
      */
 95  
     protected StrLookup() {
 96  72
         super();
 97  72
     }
 98  
 
 99  
     /**
 100  
      * Looks up a String key to a String value.
 101  
      * <p>
 102  
      * The internal implementation may use any mechanism to return the value.
 103  
      * The simplest implementation is to use a Map. However, virtually any
 104  
      * implementation is possible.
 105  
      * <p>
 106  
      * For example, it would be possible to implement a lookup that used the
 107  
      * key as a primary key, and looked up the value on demand from the database
 108  
      * Or, a numeric based implementation could be created that treats the key
 109  
      * as an integer, increments the value and return the result as a string -
 110  
      * converting 1 to 2, 15 to 16 etc.
 111  
      * <p>
 112  
      * The {@link #lookup(String)} method always returns a String, regardless of
 113  
      * the underlying data, by converting it as necessary. For example:
 114  
      * <pre>
 115  
      * Map&lt;String, Object&gt; map = new HashMap&lt;String, Object&gt;();
 116  
      * map.put("number", Integer.valueOf(2));
 117  
      * assertEquals("2", StrLookup.mapLookup(map).lookup("number"));
 118  
      * </pre>
 119  
      * @param key  the key to be looked up, may be null
 120  
      * @return the matching value, null if no match
 121  
      */
 122  
     public abstract String lookup(String key);
 123  
 
 124  
     //-----------------------------------------------------------------------
 125  
     /**
 126  
      * Lookup implementation that uses a Map.
 127  
      */
 128  
     static class MapStrLookup<V> extends StrLookup<V> {
 129  
 
 130  
         /** Map keys are variable names and value. */
 131  
         private final Map<String, V> map;
 132  
 
 133  
         /**
 134  
          * Creates a new instance backed by a Map.
 135  
          *
 136  
          * @param map  the map of keys to values, may be null
 137  
          */
 138  71
         MapStrLookup(final Map<String, V> map) {
 139  71
             this.map = map;
 140  71
         }
 141  
 
 142  
         /**
 143  
          * Looks up a String key to a String value using the map.
 144  
          * <p>
 145  
          * If the map is null, then null is returned.
 146  
          * The map result object is converted to a string using toString().
 147  
          *
 148  
          * @param key  the key to be looked up, may be null
 149  
          * @return the matching value, null if no match
 150  
          */
 151  
         @Override
 152  
         public String lookup(final String key) {
 153  791
             if (map == null) {
 154  6
                 return null;
 155  
             }
 156  785
             final Object obj = map.get(key);
 157  785
             if (obj == null) {
 158  176
                 return null;
 159  
             }
 160  609
             return obj.toString();
 161  
         }
 162  
     }
 163  
 
 164  
     //-----------------------------------------------------------------------
 165  
     /**
 166  
      * Lookup implementation based on system properties.
 167  
      */
 168  2
     private static class SystemPropertiesStrLookup extends StrLookup<String> {
 169  
         /**
 170  
          * {@inheritDoc} This implementation directly accesses system properties.
 171  
          */
 172  
         @Override
 173  
         public String lookup(final String key) {
 174  10
             if (key.length() > 0) {
 175  
                 try {
 176  8
                     return System.getProperty(key);
 177  0
                 } catch (final SecurityException scex) {
 178  
                     // Squelched. All lookup(String) will return null.
 179  
                 }
 180  
             }
 181  1
             return null;
 182  
         }
 183  
     }
 184  
 }