scolebourne 2003/09/20 05:03:52
Modified: collections/src/java/org/apache/commons/collections
MapUtils.java
Log:
Javadoc and code tidying
Revision Changes Path
1.36 +160 -191
jakarta-commons/collections/src/java/org/apache/commons/collections/MapUtils.java
Index: MapUtils.java
===================================================================
RCS file:
/home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/MapUtils.java,v
retrieving revision 1.35
retrieving revision 1.36
diff -u -r1.35 -r1.36
--- MapUtils.java 20 Sep 2003 11:26:32 -0000 1.35
+++ MapUtils.java 20 Sep 2003 12:03:52 -0000 1.36
@@ -143,34 +143,32 @@
// Type safe getters
//-------------------------------------------------------------------------
/**
- * Synonym for [EMAIL PROTECTED] Map#get(Object)}.
+ * Gets from a Map in a null-safe manner.
*
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return null if the map is null; or the result of
- * <Code>map.get(key)</Code>
- */
- public static Object getObject( Map map, Object key ) {
- if ( map != null ) {
- return map.get( key );
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map, <code>null</code> if null map input
+ */
+ public static Object getObject(final Map map, final Object key) {
+ if (map != null) {
+ return map.get(key);
}
return null;
}
/**
- * Looks up the given key in the given map, converting the result into
- * a string.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return null if the map is null; null if the value mapped by that
- * key is null; or the <Code>toString()</Code>
- * result of the value for that key
- */
- public static String getString( Map map, Object key ) {
- if ( map != null ) {
- Object answer = map.get( key );
- if ( answer != null ) {
+ * Gets a String from a Map in a null-safe manner.
+ * <p>
+ * The String is obtained via <code>toString</code>.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a String, <code>null</code> if null map input
+ */
+ public static String getString(final Map map, final Object key) {
+ if (map != null) {
+ Object answer = map.get(key);
+ if (answer != null) {
return answer.toString();
}
}
@@ -178,39 +176,32 @@
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Boolean}. If the map is null, this method returns null.
- * If the value mapped by the given key is a
- * [EMAIL PROTECTED] Boolean}, then it is returned as-is. Otherwise, if the
value
- * is a string, then if that string ignoring case equals "true", then
- * a true [EMAIL PROTECTED] Boolean} is returned. Any other string value will
- * result in a false [EMAIL PROTECTED] Boolean} being returned. OR, if the
value
- * is a [EMAIL PROTECTED] Number}, and that [EMAIL PROTECTED] Number} is 0,
then a false
- * [EMAIL PROTECTED] Boolean} is returned. Any other [EMAIL PROTECTED]
Number} value results
- * in a true [EMAIL PROTECTED] Boolean} being returned.<P>
- *
- * Any value that is not a [EMAIL PROTECTED] Boolean}, [EMAIL PROTECTED]
String} or
- * [EMAIL PROTECTED] Number} results in null being returned.<P>
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Boolean} or null
- */
- public static Boolean getBoolean( Map map, Object key ) {
- if ( map != null ) {
- Object answer = map.get( key );
- if ( answer != null ) {
- if ( answer instanceof Boolean ) {
+ * Gets a Boolean from a Map in a null-safe manner.
+ * <p>
+ * If the value is a <code>Boolean</code> it is returned directly.
+ * If the value is a <code>String</code> and it equals 'true' ignoring case
+ * then <code>true</code> is returned, otherwise <code>false</code>.
+ * If the value is a <code>Number</code> an integer zero value returns
+ * <code>false</code> and non-zero returns <code>true</code>.
+ * Otherwise, <code>null</code> is returned.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Boolean, <code>null</code> if null map
input
+ */
+ public static Boolean getBoolean(final Map map, final Object key) {
+ if (map != null) {
+ Object answer = map.get(key);
+ if (answer != null) {
+ if (answer instanceof Boolean) {
return (Boolean) answer;
- }
- else
- if ( answer instanceof String ) {
- return new Boolean( (String) answer );
- }
- else
- if ( answer instanceof Number ) {
+
+ } else if (answer instanceof String) {
+ return new Boolean((String) answer);
+
+ } else if (answer instanceof Number) {
Number n = (Number) answer;
- return ( n.intValue() != 0 ) ? Boolean.TRUE : Boolean.FALSE;
+ return (n.intValue() != 0) ? Boolean.TRUE : Boolean.FALSE;
}
}
}
@@ -218,36 +209,32 @@
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Number}. If the map is null, this method returns null.
- * Otherwise, if the key maps to a [EMAIL PROTECTED] Number}, then that number
- * is returned as-is. Otherwise, if the key maps to a [EMAIL PROTECTED]
String},
- * that string is parsed into a number using the system default
- * [EMAIL PROTECTED] NumberFormat}.<P>
- *
- * If the value is not a [EMAIL PROTECTED] Number} or a [EMAIL PROTECTED]
String}, or if
- * the value is a [EMAIL PROTECTED] String} that cannot be parsed into a
- * [EMAIL PROTECTED] Number}, then null is returned.<P>
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Number} or null
- */
- public static Number getNumber( Map map, Object key ) {
- if ( map != null ) {
- Object answer = map.get( key );
- if ( answer != null ) {
- if ( answer instanceof Number ) {
+ * Gets a Number from a Map in a null-safe manner.
+ * <p>
+ * If the value is a <code>Number</code> it is returned directly.
+ * If the value is a <code>String</code> it is converted using
+ * [EMAIL PROTECTED] NumberFormat#parse(String)} on the system default formatter
+ * returning <code>null</code> if the conversion fails.
+ * Otherwise, <code>null</code> is returned.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Number, <code>null</code> if null map input
+ */
+ public static Number getNumber(final Map map, final Object key) {
+ if (map != null) {
+ Object answer = map.get(key);
+ if (answer != null) {
+ if (answer instanceof Number) {
return (Number) answer;
- }
- else
- if ( answer instanceof String ) {
+
+ } else if (answer instanceof String) {
try {
String text = (String) answer;
- return NumberFormat.getInstance().parse( text );
- }
- catch (ParseException e) {
- logInfo( e );
+ return NumberFormat.getInstance().parse(text);
+
+ } catch (ParseException e) {
+ logInfo(e);
}
}
}
@@ -256,151 +243,133 @@
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Byte}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * byte value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Byte} or null
- */
- public static Byte getByte( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Byte from a Map in a null-safe manner.
+ * <p>
+ * The Byte is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Byte, <code>null</code> if null map input
+ */
+ public static Byte getByte(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Byte ) {
+ } else if (answer instanceof Byte) {
return (Byte) answer;
}
- return new Byte( answer.byteValue() );
+ return new Byte(answer.byteValue());
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Short}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * short value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Short} or null
- */
- public static Short getShort( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Short from a Map in a null-safe manner.
+ * <p>
+ * The Short is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Short, <code>null</code> if null map input
+ */
+ public static Short getShort(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Short ) {
+ } else if (answer instanceof Short) {
return (Short) answer;
}
- return new Short( answer.shortValue() );
+ return new Short(answer.shortValue());
}
/**
- * Looks up the given key in the given map, converting the result into
- * an [EMAIL PROTECTED] Integer}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * integer value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return an [EMAIL PROTECTED] Integer} or null
- */
- public static Integer getInteger( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Integer from a Map in a null-safe manner.
+ * <p>
+ * The Integer is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Integer, <code>null</code> if null map
input
+ */
+ public static Integer getInteger(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Integer ) {
+ } else if (answer instanceof Integer) {
return (Integer) answer;
}
- return new Integer( answer.intValue() );
+ return new Integer(answer.intValue());
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Long}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * long value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Long} or null
- */
- public static Long getLong( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Long from a Map in a null-safe manner.
+ * <p>
+ * The Long is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Long, <code>null</code> if null map input
+ */
+ public static Long getLong(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Long ) {
+ } else if (answer instanceof Long) {
return (Long) answer;
}
- return new Long( answer.longValue() );
+ return new Long(answer.longValue());
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Float}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * float value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Float} or null
- */
- public static Float getFloat( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Float from a Map in a null-safe manner.
+ * <p>
+ * The Float is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Float, <code>null</code> if null map input
+ */
+ public static Float getFloat(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Float ) {
+ } else if (answer instanceof Float) {
return (Float) answer;
}
- return new Float( answer.floatValue() );
+ return new Float(answer.floatValue());
}
/**
- * Looks up the given key in the given map, converting the result into
- * a [EMAIL PROTECTED] Double}. First, [EMAIL PROTECTED]
#getNumber(Map,Object)} is invoked.
- * If the result is null, then null is returned. Otherwise, the
- * double value of the resulting [EMAIL PROTECTED] Number} is returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Double} or null
- */
- public static Double getDouble( Map map, Object key ) {
- Number answer = getNumber( map, key );
- if ( answer == null ) {
+ * Gets a Double from a Map in a null-safe manner.
+ * <p>
+ * The Double is obtained from the results of [EMAIL PROTECTED]
#getNumber(Map,Object)}.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Double, <code>null</code> if null map input
+ */
+ public static Double getDouble(final Map map, final Object key) {
+ Number answer = getNumber(map, key);
+ if (answer == null) {
return null;
- }
- else
- if ( answer instanceof Double ) {
+ } else if (answer instanceof Double) {
return (Double) answer;
}
- return new Double( answer.doubleValue() );
+ return new Double(answer.doubleValue());
}
/**
- * Looks up the given key in the given map, returning another map.
- * If the given map is null or if the given key doesn't map to another
- * map, then this method returns null. Otherwise the mapped map is
- * returned.
- *
- * @param map the map whose value to look up
- * @param key the key whose value to look up in that map
- * @return a [EMAIL PROTECTED] Map} or null
- */
- public static Map getMap( Map map, Object key ) {
- if ( map != null ) {
- Object answer = map.get( key );
- if ( answer != null && answer instanceof Map ) {
+ * Gets a Map from a Map in a null-safe manner.
+ * <p>
+ * If the value returned from the specified map is not a Map then
+ * <code>null</code> is returned.
+ *
+ * @param map the map to use
+ * @param key the key to look up
+ * @return the value in the Map as a Map, <code>null</code> if null map input
+ */
+ public static Map getMap(final Map map, final Object key) {
+ if (map != null) {
+ Object answer = map.get(key);
+ if (answer != null && answer instanceof Map) {
return (Map) answer;
}
}
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