| 1 | package org.apache.velocity.runtime.parser.node; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2000-2002,2004 The Apache Software Foundation. |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | import org.apache.velocity.context.InternalContextAdapter; |
| 20 | import org.apache.velocity.runtime.parser.Parser; |
| 21 | import org.apache.velocity.util.introspection.IntrospectionCacheData; |
| 22 | import org.apache.velocity.util.introspection.Info; |
| 23 | import org.apache.velocity.util.introspection.VelPropertyGet; |
| 24 | |
| 25 | import org.apache.velocity.exception.MethodInvocationException; |
| 26 | import org.apache.velocity.app.event.EventCartridge; |
| 27 | |
| 28 | import java.lang.reflect.InvocationTargetException; |
| 29 | |
| 30 | /** |
| 31 | * ASTIdentifier.java |
| 32 | * |
| 33 | * Method support for identifiers : $foo |
| 34 | * |
| 35 | * mainly used by ASTRefrence |
| 36 | * |
| 37 | * Introspection is now moved to 'just in time' or at render / execution |
| 38 | * time. There are many reasons why this has to be done, but the |
| 39 | * primary two are thread safety, to remove any context-derived |
| 40 | * information from class member variables. |
| 41 | * |
| 42 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| 43 | * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| 44 | * @version $Id: ASTIdentifier.java,v 1.19.4.1 2004/03/03 23:22:58 geirm Exp $ |
| 45 | */ |
| 46 | public class ASTIdentifier extends SimpleNode |
| 47 | { |
| 48 | private String identifier = ""; |
| 49 | |
| 50 | /** |
| 51 | * This is really immutable after the init, so keep one for this node |
| 52 | */ |
| 53 | protected Info uberInfo; |
| 54 | |
| 55 | public ASTIdentifier(int id) |
| 56 | { |
| 57 | super(id); |
| 58 | } |
| 59 | |
| 60 | public ASTIdentifier(Parser p, int id) |
| 61 | { |
| 62 | super(p, id); |
| 63 | } |
| 64 | |
| 65 | /** Accept the visitor. **/ |
| 66 | public Object jjtAccept(ParserVisitor visitor, Object data) |
| 67 | { |
| 68 | return visitor.visit(this, data); |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * simple init - don't do anything that is context specific. |
| 73 | * just get what we need from the AST, which is static. |
| 74 | */ |
| 75 | public Object init(InternalContextAdapter context, Object data) |
| 76 | throws Exception |
| 77 | { |
| 78 | super.init(context, data); |
| 79 | |
| 80 | identifier = getFirstToken().image; |
| 81 | |
| 82 | uberInfo = new Info(context.getCurrentTemplateName(), |
| 83 | getLine(), getColumn()); |
| 84 | |
| 85 | return data; |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * invokes the method on the object passed in |
| 90 | */ |
| 91 | public Object execute(Object o, InternalContextAdapter context) |
| 92 | throws MethodInvocationException |
| 93 | { |
| 94 | |
| 95 | VelPropertyGet vg = null; |
| 96 | |
| 97 | try |
| 98 | { |
| 99 | Class c = o.getClass(); |
| 100 | |
| 101 | /* |
| 102 | * first, see if we have this information cached. |
| 103 | */ |
| 104 | |
| 105 | IntrospectionCacheData icd = context.icacheGet(this); |
| 106 | |
| 107 | /* |
| 108 | * if we have the cache data and the class of the object we are |
| 109 | * invoked with is the same as that in the cache, then we must |
| 110 | * be allright. The last 'variable' is the method name, and |
| 111 | * that is fixed in the template :) |
| 112 | */ |
| 113 | |
| 114 | if (icd != null && icd.contextData == c) |
| 115 | { |
| 116 | vg = (VelPropertyGet) icd.thingy; |
| 117 | } |
| 118 | else |
| 119 | { |
| 120 | /* |
| 121 | * otherwise, do the introspection, and cache it. Use the |
| 122 | * uberspector |
| 123 | */ |
| 124 | |
| 125 | vg = rsvc.getUberspect().getPropertyGet(o,identifier, uberInfo); |
| 126 | |
| 127 | if (vg != null && vg.isCacheable()) |
| 128 | { |
| 129 | icd = new IntrospectionCacheData(); |
| 130 | icd.contextData = c; |
| 131 | icd.thingy = vg; |
| 132 | context.icachePut(this,icd); |
| 133 | } |
| 134 | } |
| 135 | } |
| 136 | catch(Exception e) |
| 137 | { |
| 138 | rsvc.error("ASTIdentifier.execute() : identifier = " |
| 139 | + identifier + " : " + e); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * we have no getter... punt... |
| 144 | */ |
| 145 | |
| 146 | if (vg == null) |
| 147 | { |
| 148 | return null; |
| 149 | } |
| 150 | |
| 151 | /* |
| 152 | * now try and execute. If we get a MIE, throw that |
| 153 | * as the app wants to get these. If not, log and punt. |
| 154 | */ |
| 155 | try |
| 156 | { |
| 157 | return vg.invoke(o); |
| 158 | } |
| 159 | catch(InvocationTargetException ite) |
| 160 | { |
| 161 | EventCartridge ec = context.getEventCartridge(); |
| 162 | |
| 163 | /* |
| 164 | * if we have an event cartridge, see if it wants to veto |
| 165 | * also, let non-Exception Throwables go... |
| 166 | */ |
| 167 | |
| 168 | if (ec != null |
| 169 | && ite.getTargetException() instanceof java.lang.Exception) |
| 170 | { |
| 171 | try |
| 172 | { |
| 173 | return ec.methodException(o.getClass(), vg.getMethodName(), |
| 174 | (Exception)ite.getTargetException()); |
| 175 | } |
| 176 | catch(Exception e) |
| 177 | { |
| 178 | throw new MethodInvocationException( |
| 179 | "Invocation of method '" + vg.getMethodName() + "'" |
| 180 | + " in " + o.getClass() |
| 181 | + " threw exception " |
| 182 | + ite.getTargetException().getClass() + " : " |
| 183 | + ite.getTargetException().getMessage(), |
| 184 | ite.getTargetException(), vg.getMethodName()); |
| 185 | } |
| 186 | } |
| 187 | else |
| 188 | { |
| 189 | /* |
| 190 | * no event cartridge to override. Just throw |
| 191 | */ |
| 192 | |
| 193 | throw new MethodInvocationException( |
| 194 | "Invocation of method '" + vg.getMethodName() + "'" |
| 195 | + " in " + o.getClass() |
| 196 | + " threw exception " |
| 197 | + ite.getTargetException().getClass() + " : " |
| 198 | + ite.getTargetException().getMessage(), |
| 199 | ite.getTargetException(), vg.getMethodName()); |
| 200 | |
| 201 | |
| 202 | } |
| 203 | } |
| 204 | catch(IllegalArgumentException iae) |
| 205 | { |
| 206 | return null; |
| 207 | } |
| 208 | catch(Exception e) |
| 209 | { |
| 210 | rsvc.error("ASTIdentifier() : exception invoking method " |
| 211 | + "for identifier '" + identifier + "' in " |
| 212 | + o.getClass() + " : " + e); |
| 213 | } |
| 214 | |
| 215 | return null; |
| 216 | } |
| 217 | } |