| 1 | // SECTION-START[License Header] |
| 2 | // <editor-fold defaultstate="collapsed" desc=" Generated License "> |
| 3 | /* |
| 4 | * Copyright (c) 2010 The JOMC Project |
| 5 | * Copyright (c) 2005 Christian Schulte <cs@jomc.org> |
| 6 | * All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * |
| 12 | * o Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * |
| 15 | * o Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in |
| 17 | * the documentation and/or other materials provided with the |
| 18 | * distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE JOMC PROJECT AND CONTRIBUTORS "AS IS" |
| 21 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 22 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE JOMC PROJECT OR |
| 24 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 25 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 26 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 27 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 28 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 29 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 30 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | * $Id: DefaultInvoker.java 1346 2010-01-19 12:16:43Z schulte2005 $ |
| 33 | * |
| 34 | */ |
| 35 | // </editor-fold> |
| 36 | // SECTION-END |
| 37 | package org.jomc.ri; |
| 38 | |
| 39 | import java.lang.reflect.InvocationTargetException; |
| 40 | import org.jomc.model.Instance; |
| 41 | import org.jomc.spi.Invocation; |
| 42 | import org.jomc.spi.Invoker; |
| 43 | |
| 44 | // SECTION-START[Documentation] |
| 45 | // <editor-fold defaultstate="collapsed" desc=" Generated Documentation "> |
| 46 | /** |
| 47 | * Default {@code Invoker} implementation. |
| 48 | * |
| 49 | * @author <a href="mailto:cs@jomc.org">Christian Schulte</a> 1.0 |
| 50 | * @version $Id: DefaultInvoker.java 1346 2010-01-19 12:16:43Z schulte2005 $ |
| 51 | */ |
| 52 | // </editor-fold> |
| 53 | // SECTION-END |
| 54 | // SECTION-START[Annotations] |
| 55 | // <editor-fold defaultstate="collapsed" desc=" Generated Annotations "> |
| 56 | @javax.annotation.Generated( value = "org.jomc.tools.JavaSources", |
| 57 | comments = "See http://jomc.sourceforge.net/jomc/1.0-alpha-15/jomc-tools" ) |
| 58 | // </editor-fold> |
| 59 | // SECTION-END |
| 60 | public class DefaultInvoker implements Invoker |
| 61 | { |
| 62 | // SECTION-START[Invoker] |
| 63 | |
| 64 | /** |
| 65 | * Performs a method invocation on an object. |
| 66 | * <p>This method first passes the given invocation to the {@code preInvoke} method. If the result property of the |
| 67 | * invocation returned by the {@code preInvoke} method is an instance of {@code Throwable}, that instance will be |
| 68 | * thrown; otherwise the invocation returned by the {@code preInvoke} method is performed and then passed to the |
| 69 | * {@code postInvoke} method. If the result property of the invocation returned from the {@code postInvoke} method |
| 70 | * is an instance of {@code Throwable}, that instance will be thrown; otherwise the value of the result property is |
| 71 | * returned by this method.</p> |
| 72 | * |
| 73 | * @param invocation The invocation to perform. |
| 74 | * |
| 75 | * @return The return value of the invocation. If the declared return type of the method of the invocation is a |
| 76 | * primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper |
| 77 | * class; otherwise, it must be a type assignable to the declared return type of the method of the invocation. |
| 78 | * If the value returned by this method is {@code null} and the declared return type of the method of the invocation |
| 79 | * is primitive, then a {@code NullPointerException} will be thrown. If the value returned by this method is |
| 80 | * otherwise not compatible to the declared return type of the method of the invocation, a |
| 81 | * {@code ClassCastException} will be thrown. |
| 82 | * |
| 83 | * @throws Throwable The exception thrown from the method invocation. The exception's type must be assignable |
| 84 | * either to any of the exception types declared in the {@code throws} clause of the method of the invocation or to |
| 85 | * the unchecked exception types {@code java.lang.RuntimeException} or {@code java.lang.Error}. |
| 86 | * If a checked exception is thrown by this method that is not assignable to any of the exception types declared in |
| 87 | * the {@code throws} clause of the method of the invocation, then an {@code UndeclaredThrowableException} |
| 88 | * containing the exception that was thrown by this method will be thrown. |
| 89 | * |
| 90 | * @see #preInvoke(org.jomc.spi.Invocation) |
| 91 | * @see #postInvoke(org.jomc.spi.Invocation) |
| 92 | */ |
| 93 | public Object invoke( final Invocation invocation ) throws Throwable |
| 94 | { |
| 95 | Invocation current = invocation; |
| 96 | final Instance instance = (Instance) current.getContext().get( DefaultInvocation.INSTANCE_KEY ); |
| 97 | |
| 98 | try |
| 99 | { |
| 100 | if ( instance != null && instance.isStateless() ) |
| 101 | { |
| 102 | try |
| 103 | { |
| 104 | current = this.preInvoke( current ); |
| 105 | } |
| 106 | catch ( final Throwable t ) |
| 107 | { |
| 108 | this.handleException( current, t ); |
| 109 | } |
| 110 | |
| 111 | if ( !( current.getResult() instanceof Throwable ) ) |
| 112 | { |
| 113 | try |
| 114 | { |
| 115 | current.setResult( current.getMethod().invoke( current.getObject(), current.getArguments() ) ); |
| 116 | } |
| 117 | catch ( final Throwable t ) |
| 118 | { |
| 119 | this.handleException( current, t ); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | try |
| 124 | { |
| 125 | current = this.postInvoke( current ); |
| 126 | } |
| 127 | catch ( final Throwable t ) |
| 128 | { |
| 129 | this.handleException( current, t ); |
| 130 | } |
| 131 | |
| 132 | if ( current.getResult() instanceof Throwable ) |
| 133 | { |
| 134 | throw (Throwable) current.getResult(); |
| 135 | } |
| 136 | |
| 137 | return current.getResult(); |
| 138 | } |
| 139 | else |
| 140 | { |
| 141 | synchronized ( invocation.getObject() ) |
| 142 | { |
| 143 | try |
| 144 | { |
| 145 | current = this.preInvoke( current ); |
| 146 | } |
| 147 | catch ( final Throwable t ) |
| 148 | { |
| 149 | this.handleException( current, t ); |
| 150 | } |
| 151 | |
| 152 | if ( !( current.getResult() instanceof Throwable ) ) |
| 153 | { |
| 154 | try |
| 155 | { |
| 156 | current.setResult( current.getMethod().invoke( current.getObject(), |
| 157 | current.getArguments() ) ); |
| 158 | |
| 159 | } |
| 160 | catch ( final Throwable t ) |
| 161 | { |
| 162 | this.handleException( current, t ); |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | try |
| 167 | { |
| 168 | current = this.postInvoke( current ); |
| 169 | } |
| 170 | catch ( final Throwable t ) |
| 171 | { |
| 172 | this.handleException( current, t ); |
| 173 | } |
| 174 | |
| 175 | if ( current.getResult() instanceof Throwable ) |
| 176 | { |
| 177 | throw (Throwable) current.getResult(); |
| 178 | } |
| 179 | |
| 180 | return current.getResult(); |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | finally |
| 185 | { |
| 186 | invocation.getContext().clear(); |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | // SECTION-END |
| 191 | // SECTION-START[DefaultInvoker] |
| 192 | /** |
| 193 | * Called before an invocation is performed. |
| 194 | * <p>Overriding classes may use this method to perform any kind of operation prior to an invocation and to create |
| 195 | * custom invocation instances. If an overriding class wishes to throw an exception, it may do so by setting the |
| 196 | * result property of the returned invocation to an instance of {@code Throwable} thrown as the result of the |
| 197 | * invocation. If an overriding class wishes to provide a custom {@code Invocation} class, it may do so by returning |
| 198 | * a different instance from this method. By default, this method does nothing and returns the given invocation |
| 199 | * unchanged.</p> |
| 200 | * |
| 201 | * @param invocation The invocation about to be performed. |
| 202 | * |
| 203 | * @return The processed invocation. |
| 204 | * |
| 205 | * @throws NullPointerException if {@code invocation} is {@code null}. |
| 206 | */ |
| 207 | public Invocation preInvoke( final Invocation invocation ) |
| 208 | { |
| 209 | if ( invocation == null ) |
| 210 | { |
| 211 | throw new NullPointerException( "invocation" ); |
| 212 | } |
| 213 | |
| 214 | return invocation; |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Called after an invocation has been performed. |
| 219 | * <p>Overriding classes may use this method to perform any kind of operation after an invocation has been |
| 220 | * performed and to maintain custom invocation instances. If an overriding class wishes to throw an exception, it |
| 221 | * may do so by setting the result property of the returned invocation to an instance of {@code Throwable} thrown as |
| 222 | * the result of the invocation. Since the result property of the given invocation already holds the result of the |
| 223 | * invocation (which may already be an instance of {@code Throwable}), care must be taken when updating that result. |
| 224 | * By default, this method does nothing and returns the given invocation unchanged.</p> |
| 225 | * |
| 226 | * @param invocation The performed invocation. |
| 227 | * |
| 228 | * @return The processed invocation. |
| 229 | * |
| 230 | * @throws NullPointerException if {@code invocation} is {@code null}. |
| 231 | */ |
| 232 | public Invocation postInvoke( final Invocation invocation ) |
| 233 | { |
| 234 | if ( invocation == null ) |
| 235 | { |
| 236 | throw new NullPointerException( "invocation" ); |
| 237 | } |
| 238 | |
| 239 | return invocation; |
| 240 | } |
| 241 | |
| 242 | /** |
| 243 | * Called whenever an exception has been caught. |
| 244 | * <p>Overriding classes may use this method for handling exceptions. By default, this method updates the result of |
| 245 | * the given invocation with the given throwable. If that throwable is an instance of |
| 246 | * {@code InvocationTargetException}, this method updates the result with the value of that exception's target |
| 247 | * exception. If the result of the given invocation already is an instance of {@code Throwable}, this method does |
| 248 | * not update the result.</p> |
| 249 | * |
| 250 | * @param invocation The invocation to update. |
| 251 | * @param t The throwable to update {@code invocation} with. |
| 252 | */ |
| 253 | public void handleException( final Invocation invocation, final Throwable t ) |
| 254 | { |
| 255 | if ( invocation != null && !( invocation.getResult() instanceof Throwable ) ) |
| 256 | { |
| 257 | if ( t instanceof InvocationTargetException && |
| 258 | ( (InvocationTargetException) t ).getTargetException() != null ) |
| 259 | { |
| 260 | invocation.setResult( ( (InvocationTargetException) t ).getTargetException() ); |
| 261 | return; |
| 262 | } |
| 263 | |
| 264 | invocation.setResult( t ); |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | // SECTION-END |
| 269 | // SECTION-START[Constructors] |
| 270 | // <editor-fold defaultstate="collapsed" desc=" Generated Constructors "> |
| 271 | |
| 272 | /** Creates a new {@code DefaultInvoker} instance. */ |
| 273 | @javax.annotation.Generated( value = "org.jomc.tools.JavaSources", |
| 274 | comments = "See http://jomc.sourceforge.net/jomc/1.0-alpha-15/jomc-tools" ) |
| 275 | public DefaultInvoker() |
| 276 | { |
| 277 | // SECTION-START[Default Constructor] |
| 278 | super(); |
| 279 | // SECTION-END |
| 280 | } |
| 281 | // </editor-fold> |
| 282 | // SECTION-END |
| 283 | // SECTION-START[Dependencies] |
| 284 | // SECTION-END |
| 285 | // SECTION-START[Properties] |
| 286 | // SECTION-END |
| 287 | // SECTION-START[Messages] |
| 288 | // SECTION-END |
| 289 | } |