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1
18 package org.apache.beehive.netui.script.el.util;
19
20 import java.io.StringReader  ;
21 import java.lang.reflect.Array ;
22 import java.lang.reflect.Method ;
23 import java.util.HashMap ;
24
25 import org.apache.beehive.netui.script.el.parser.NetUIELParser;
26 import org.apache.beehive.netui.script.el.NetUIVariableResolver;
27 import org.apache.beehive.netui.script.el.ParsedExpression;
28 import org.apache.beehive.netui.script.el.ExpressionParseException;
29 import org.apache.beehive.netui.script.el.parser.TokenMgrError;
30 import org.apache.beehive.netui.script.el.parser.ParseException;
31 import org.apache.beehive.netui.util.internal.InternalStringBuilder;
32 import org.apache.beehive.netui.util.internal.cache.PropertyCache;
33 import org.apache.beehive.netui.util.type.TypeUtils;
34 import org.apache.beehive.netui.util.logging.Logger;
35
36
39 public class ParseUtils {
40
41 private static final Logger LOGGER = Logger.getInstance(ParseUtils.class);
42
43 private static final HashMap PARSED_CACHE = new HashMap ();
44
45
46 private ParseUtils() {}
47
48 public static final ParsedExpression parse(String exprStr) {
49 ParsedExpression pe = (ParsedExpression) PARSED_CACHE.get(exprStr);
50
51 if(pe != null)
52 return pe;
53
54 try {
55 NetUIELParser learn = new NetUIELParser(new StringReader (exprStr));
56
57 ParsedExpression expr = learn.parse();
58 expr.seal();
59
60
61 synchronized(PARSED_CACHE) {
62 PARSED_CACHE.put(exprStr, expr);
63 }
64
65 return expr;
66 } catch(ParseException e) {
67 String msg = "Error occurred parsing expression \"" + exprStr + "\".";
68 LOGGER.error(msg, e);
69 throw new ExpressionParseException(msg, e);
70 } catch(TokenMgrError tm) {
71 String msg = "Error occurred parsing expression \"" + exprStr + "\".";
72 LOGGER.error(msg, tm);
73 throw new ExpressionParseException(msg, tm);
74 }
75 }
76
77 public static final Object evaluate(String exprStr, NetUIVariableResolver vr) {
78 ParsedExpression expr = parse(exprStr);
79 assert expr != null;
80 return expr.evaluate(vr);
81 }
82
83 public static final void update(String exprStr, Object value, NetUIVariableResolver vr) {
84 ParsedExpression expr = parse(exprStr);
85 assert expr != null;
86 expr.update(value, vr);
87 }
88
89 public static final Class getPropertyType(Object value, String name, PropertyCache cache) {
90 assert value != null;
91 assert cache != null;
92
93 Class type = value.getClass();
94
95 Method m = cache.getPropertySetter(type, name);
96 if(m == null) {
97 String msg = "Can not find setter method for property \"" + name + "\" on object of type \"" + value.getClass() + "\".";
98 LOGGER.error(msg);
99 throw new RuntimeException (msg);
100 }
101 else {
103 assert m.getParameterTypes().length == 1;
104 return m.getParameterTypes()[0];
105 }
106 }
107
108 public static final Object getProperty(Object value, String name, PropertyCache cache) {
109 assert value != null;
110 assert cache != null;
111
112 Class type = value.getClass();
113
114 Method m = cache.getPropertyGetter(type, name);
115 if(m != null) {
116 try {
117 return m.invoke(value, (Object [])null);
118 } catch(Exception e) {
119 String msg = "An error occurred invoking a getter for the property \"" + name + "\" on an object of type \"" + type + "\".";
120 LOGGER.error(msg, e);
121 throw new RuntimeException (msg, e);
122 }
123 }
124
125 String msg = "Could not find JavaBean property named \"" + name + "\" on object of type \"" + type + "\"";
126 LOGGER.error(msg);
127 throw new RuntimeException (msg);
128 }
129
130 public static final Object convertType(Object value, Class toType) {
131 assert toType != null;
132
133 try {
134 boolean sourceIsArray = false;
135
136
137 if(value != null && !(value instanceof String || (sourceIsArray = (value instanceof String []))))
138 return value;
139
140
141 if(toType.isArray()) {
142 if(value == null)
143 return null;
144 else {
145 Class compType = toType.getComponentType();
146
147 String [] strs = null;
148 if(value.getClass().isArray())
149 strs = (String [])value;
150 else
151 strs = new String []{(String )value};
152
153 Object tgt = Array.newInstance(compType, strs.length);
154
155 for(int i = 0; i < strs.length; i++) {
156 Object o = null;
157 try {
158
159 o = TypeUtils.convertToObject(strs[i], compType);
160 } catch(IllegalArgumentException e) {
161 String msg = "Can not set Object types via expressions that are not supported by the set of registered type converters. Cause: " + e;
162 LOGGER.error(msg, e);
163 throw new RuntimeException (msg, e);
164 }
165
166 Array.set(tgt, i, o);
167 }
168
169 return tgt;
170 }
171 }
172 else {
174 if(sourceIsArray) {
179 assert value instanceof String [];
180 assert Array.getLength(value) > 0 && Array.getLength(value) - 1 >= 0;
181
182 value = Array.get(value, Array.getLength(value) - 1);
183 }
184
185 try {
186 assert value == null || value instanceof String ;
187
188 return TypeUtils.convertToObject((String )value, toType);
189 } catch(IllegalArgumentException e) {
190 String msg = "The type \"" + toType.getName() + "\" can not be set through the NetUI expression language.";
191 LOGGER.error(msg, e);
192 throw new RuntimeException (msg, e);
193 }
194 }
195 } catch(Exception e) {
196 String msg = "Unable to convert a value of type \"" + value.getClass() + "\" to the array element type of \"" + toType + "\". Cause: " + e;
197 LOGGER.error(msg, e);
198 throw new RuntimeException (msg, e);
199 }
200 }
201
202 public static String getContextString(String [] contexts) {
203 InternalStringBuilder builder = new InternalStringBuilder();
204 builder.append("[");
205 if(contexts != null) {
206 for(int i = 0; i < contexts.length; i++) {
207 if(i > 0) builder.append(", ");
208 builder.append(contexts[i]);
209 }
210 }
211 builder.append("]");
212 return builder.toString();
213 }
214
215 public static Throwable getRootCause(Throwable t) {
216 Throwable root = t;
217 while(root.getCause() != null)
218 root = root.getCause();
219 return root;
220 }
221 }
222 |
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