001 /**
002 *
003 */
004 package org.wdssii.core;
005
006 import java.beans.BeanInfo;
007 import java.beans.Introspector;
008 import java.beans.PropertyDescriptor;
009 import java.lang.reflect.Method;
010 import java.util.Enumeration;
011 import java.util.HashSet;
012 import java.util.List;
013 import java.util.Properties;
014 import java.util.Set;
015
016 import org.apache.commons.logging.Log;
017 import org.apache.commons.logging.LogFactory;
018
019 /**
020 * A generic property setter that uses a Properties file to set properties on an
021 * object. Built on top of java.beans
022 *
023 * @author lakshman
024 *
025 */
026 public class PropertyGetterSetter {
027 private static Log log = LogFactory.getLog(PropertyGetterSetter.class);
028
029 /**
030 * Invoke any setter method on object if the corresponding property is found
031 * in props. If any properties are not set, explanation of why is sent to
032 * the debug log.
033 *
034 * @param object
035 * whose setter methods should be invoked
036 * @param props
037 * contains name=value pairs with the corresponding properties
038 */
039 @SuppressWarnings("unchecked")
040 public static void setProperties(Object object, Properties props) {
041 try {
042 BeanInfo p = Introspector.getBeanInfo(object.getClass(),
043 Object.class);
044
045 // Get the list of all keys, including those in defaults backing
046 // props
047 Enumeration keyIter = props.propertyNames();
048 Set<String> keys = new HashSet<String>();
049 while (keyIter.hasMoreElements()) {
050 keys.add((String) keyIter.nextElement());
051 }
052
053 PropertyDescriptor[] propDescriptors = p.getPropertyDescriptors();
054 for (PropertyDescriptor propDescriptor : propDescriptors) {
055 // get name of property
056 String name = propDescriptor.getName();
057
058 if (keys.contains(name) == false) {
059 if (log.isDebugEnabled()) {
060 log
061 .debug("Property "
062 + name
063 + " not set as the key was not found in properties passed in");
064 }
065 continue;
066 }
067 // find setter method and expected param type
068 Method setter = propDescriptor.getWriteMethod();
069
070 // set the property
071 String value = props.getProperty(name);
072 setProperty(object, setter, name, value);
073 }
074 } catch (Exception e) {
075 log.warn("Properties not set: ", e);
076 }
077 }
078
079 /**
080 * Invoke all getter methods on object
081 *
082 * @param object
083 * whose getter methods should be invoked
084 * @return properties object that contains name=value pairs with the
085 * corresponding properties
086 */
087 public static Properties getProperties(Object object) {
088 Properties result = new Properties();
089 try {
090 BeanInfo p = Introspector.getBeanInfo(object.getClass(),
091 Object.class);
092
093 PropertyDescriptor[] propDescriptors = p.getPropertyDescriptors();
094 for (PropertyDescriptor propDescriptor : propDescriptors) {
095 try {
096 String name = propDescriptor.getName();
097 Method getter = propDescriptor.getReadMethod();
098 String value = getter.invoke(object, (Object[]) null)
099 .toString();
100 result.setProperty(name, value);
101 if (log.isDebugEnabled()) {
102 log.debug(name + "=" + value);
103 }
104 } catch (Exception e) {
105 if (log.isDebugEnabled()) {
106 log.debug("Skipping " + propDescriptor + ": " + e);
107 }
108 }
109 }
110 } catch (Exception e) {
111 log.error("Could not get properties: ", e);
112 }
113 return result;
114 }
115
116 /**
117 * Invoke setter on object with the provided value.
118 *
119 * @param object
120 * @param setter
121 * @param name
122 * name of property (used only for logging)
123 * @param value
124 * value to call setter method with
125 * @return whether the setter method succeeded. On failure, see debug log.
126 */
127 @SuppressWarnings("unchecked")
128 public static boolean setProperty(Object object, Method setter,
129 String name, String value) {
130 Object settableValue = null;
131 try {
132 // Find paramType
133 Class[] paramTypes = setter.getParameterTypes();
134 if (paramTypes.length != 1) {
135 if (log.isDebugEnabled()) {
136 log
137 .debug("Not setting "
138 + name
139 + " since the number of parameters in setter method is not 1");
140 }
141 return false;
142 }
143 Class paramType = paramTypes[0];
144
145 // convert the value to the appropriate type
146 if (value != null) {
147 if (String.class.isAssignableFrom(paramType)) {
148 settableValue = value;
149 } else if (Boolean.TYPE.isAssignableFrom(paramType)) {
150 if (value.equals("true")) {
151 settableValue = Boolean.TRUE;
152 } else {
153 settableValue = Boolean.FALSE;
154 }
155 } else if (Short.TYPE.isAssignableFrom(paramType)) {
156 settableValue = Short.parseShort(value);
157 } else if (Integer.TYPE.isAssignableFrom(paramType)) {
158 settableValue = Integer.parseInt(value);
159 } else if (Long.TYPE.isAssignableFrom(paramType)) {
160 settableValue = Long.parseLong(value);
161 } else if (Float.TYPE.isAssignableFrom(paramType)) {
162 settableValue = Float.parseFloat(value);
163 } else if (Double.TYPE.isAssignableFrom(paramType)) {
164 settableValue = Double.parseDouble(value);
165 } else if (double[].class.isAssignableFrom(paramType)){
166 List<String> pieces = StringUtil.split(value);
167 double[] values = new double[pieces.size()];
168 for (int i=0; i < values.length; ++i){
169 values[i] = Double.parseDouble(pieces.get(i));
170 }
171 settableValue = values;
172 } else if (float[].class.isAssignableFrom(paramType)){
173 List<String> pieces = StringUtil.split(value);
174 float[] values = new float[pieces.size()];
175 for (int i=0; i < values.length; ++i){
176 values[i] = Float.parseFloat(pieces.get(i));
177 }
178 settableValue = values;
179 } else if (int[].class.isAssignableFrom(paramType)){
180 List<String> pieces = StringUtil.split(value);
181 int[] values = new int[pieces.size()];
182 for (int i=0; i < values.length; ++i){
183 values[i] = Integer.parseInt(pieces.get(i));
184 }
185 settableValue = values;
186 }
187 else {
188 log.debug("Unsupported type: " + paramType);
189 return false;
190 }
191 }
192
193 // invoke method
194 setter.invoke(object, new Object[] { settableValue });
195 if (log.isInfoEnabled()) {
196 log.info("Set " + name + "=" + settableValue);
197 }
198 return true;
199 } catch (Exception e) {
200 log.debug(
201 "Unable to set name= " + name + " value=" + settableValue,
202 e);
203 return false;
204 }
205 }
206 }