| 1 | /* |
| 2 | * Copyright 2006-2008 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.springframework.batch.core.configuration.xml; |
| 17 | |
| 18 | import java.util.ArrayList; |
| 19 | import java.util.Arrays; |
| 20 | import java.util.Collection; |
| 21 | import java.util.HashMap; |
| 22 | import java.util.HashSet; |
| 23 | import java.util.List; |
| 24 | import java.util.Map; |
| 25 | import java.util.Set; |
| 26 | |
| 27 | import org.springframework.batch.core.job.flow.FlowExecutionStatus; |
| 28 | import org.springframework.batch.core.job.flow.support.SimpleFlow; |
| 29 | import org.springframework.beans.factory.config.BeanDefinition; |
| 30 | import org.springframework.beans.factory.parsing.CompositeComponentDefinition; |
| 31 | import org.springframework.beans.factory.support.BeanDefinitionBuilder; |
| 32 | import org.springframework.beans.factory.support.ManagedList; |
| 33 | import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser; |
| 34 | import org.springframework.beans.factory.xml.ParserContext; |
| 35 | import org.springframework.util.StringUtils; |
| 36 | import org.springframework.util.xml.DomUtils; |
| 37 | import org.w3c.dom.Element; |
| 38 | import org.w3c.dom.Node; |
| 39 | import org.w3c.dom.NodeList; |
| 40 | |
| 41 | /** |
| 42 | * @author Dave Syer |
| 43 | * |
| 44 | */ |
| 45 | public class FlowParser extends AbstractSingleBeanDefinitionParser { |
| 46 | |
| 47 | private static final String ID_ATTR = "id"; |
| 48 | |
| 49 | private static final String STEP_ELE = "step"; |
| 50 | |
| 51 | private static final String DECISION_ELE = "decision"; |
| 52 | |
| 53 | private static final String SPLIT_ELE = "split"; |
| 54 | |
| 55 | private static final String NEXT_ATTR = "next"; |
| 56 | |
| 57 | private static final String NEXT_ELE = "next"; |
| 58 | |
| 59 | private static final String END_ELE = "end"; |
| 60 | |
| 61 | private static final String FAIL_ELE = "fail"; |
| 62 | |
| 63 | private static final String STOP_ELE = "stop"; |
| 64 | |
| 65 | private static final String ON_ATTR = "on"; |
| 66 | |
| 67 | private static final String TO_ATTR = "to"; |
| 68 | |
| 69 | private static final String RESTART_ATTR = "restart"; |
| 70 | |
| 71 | private static final String EXIT_CODE_ATTR = "exit-code"; |
| 72 | |
| 73 | private static final InlineStepParser stepParser = new InlineStepParser(); |
| 74 | |
| 75 | private static final DecisionParser decisionParser = new DecisionParser(); |
| 76 | |
| 77 | // For generating unique state names for end transitions |
| 78 | private static int endCounter = 0; |
| 79 | |
| 80 | private final String flowName; |
| 81 | |
| 82 | private final String jobFactoryRef; |
| 83 | |
| 84 | /** |
| 85 | * Construct a {@link FlowParser} with the specified name and using the |
| 86 | * provided job repository ref. |
| 87 | * |
| 88 | * @param flowName the name of the flow |
| 89 | * @param jobFactoryRef the reference to the {@link JobParserJobFactoryBean} |
| 90 | * from the enclosing tag |
| 91 | */ |
| 92 | public FlowParser(String flowName, String jobFactoryRef) { |
| 93 | this.flowName = flowName; |
| 94 | this.jobFactoryRef = jobFactoryRef; |
| 95 | |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * (non-Javadoc) |
| 100 | * |
| 101 | * @see AbstractSingleBeanDefinitionParser#getBeanClass(Element) |
| 102 | */ |
| 103 | @Override |
| 104 | protected Class<SimpleFlow> getBeanClass(Element element) { |
| 105 | return SimpleFlow.class; |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * @param element the top level element containing a flow definition |
| 110 | * @param parserContext the {@link ParserContext} |
| 111 | */ |
| 112 | @Override |
| 113 | protected void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) { |
| 114 | List<BeanDefinition> stateTransitions = new ArrayList<BeanDefinition>(); |
| 115 | |
| 116 | SplitParser splitParser = new SplitParser(jobFactoryRef); |
| 117 | CompositeComponentDefinition compositeDef = new CompositeComponentDefinition(element.getTagName(), |
| 118 | parserContext.extractSource(element)); |
| 119 | parserContext.pushContainingComponent(compositeDef); |
| 120 | |
| 121 | boolean stepExists = false; |
| 122 | Map<String, Set<String>> reachableElementMap = new HashMap<String, Set<String>>(); |
| 123 | String startElement = null; |
| 124 | NodeList children = element.getChildNodes(); |
| 125 | for (int i = 0; i < children.getLength(); i++) { |
| 126 | Node node = children.item(i); |
| 127 | if (node instanceof Element) { |
| 128 | String nodeName = node.getLocalName(); |
| 129 | Element child = (Element) node; |
| 130 | if (nodeName.equals(STEP_ELE)) { |
| 131 | stateTransitions.addAll(stepParser.parse(child, parserContext, jobFactoryRef)); |
| 132 | stepExists = true; |
| 133 | } |
| 134 | else if (nodeName.equals(DECISION_ELE)) { |
| 135 | stateTransitions.addAll(decisionParser.parse(child, parserContext)); |
| 136 | } |
| 137 | else if (nodeName.equals(SPLIT_ELE)) { |
| 138 | stateTransitions.addAll(splitParser |
| 139 | .parse(child, new ParserContext(parserContext.getReaderContext(), parserContext |
| 140 | .getDelegate(), builder.getBeanDefinition()))); |
| 141 | stepExists = true; |
| 142 | } |
| 143 | |
| 144 | if (Arrays.asList(STEP_ELE, DECISION_ELE, SPLIT_ELE).contains(nodeName)) { |
| 145 | reachableElementMap.put(child.getAttribute(ID_ATTR), findReachableElements(child)); |
| 146 | if (startElement == null) { |
| 147 | startElement = child.getAttribute(ID_ATTR); |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | if (!stepExists && !StringUtils.hasText(element.getAttribute("parent"))) { |
| 154 | parserContext.getReaderContext().error("The flow [" + flowName + "] must contain at least one step", |
| 155 | element); |
| 156 | } |
| 157 | |
| 158 | // Ensure that all elements are reachable |
| 159 | Set<String> allReachableElements = new HashSet<String>(); |
| 160 | findAllReachableElements(startElement, reachableElementMap, allReachableElements); |
| 161 | for (String elementId : reachableElementMap.keySet()) { |
| 162 | if (!allReachableElements.contains(elementId)) { |
| 163 | parserContext.getReaderContext().error("The element [" + elementId + "] is unreachable", element); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | builder.addConstructorArgValue(flowName); |
| 168 | ManagedList managedList = new ManagedList(); |
| 169 | @SuppressWarnings( { "unchecked", "unused" }) |
| 170 | boolean dummy = managedList.addAll(stateTransitions); |
| 171 | builder.addPropertyValue("stateTransitions", managedList); |
| 172 | |
| 173 | builder.setRole(BeanDefinition.ROLE_INFRASTRUCTURE); |
| 174 | |
| 175 | parserContext.popAndRegisterContainingComponent(); |
| 176 | |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * Find all of the elements that are pointed to by this element. |
| 181 | * |
| 182 | * @param element |
| 183 | * @return a collection of reachable element names |
| 184 | */ |
| 185 | private Set<String> findReachableElements(Element element) { |
| 186 | Set<String> reachableElements = new HashSet<String>(); |
| 187 | |
| 188 | String nextAttribute = element.getAttribute(NEXT_ATTR); |
| 189 | if (StringUtils.hasText(nextAttribute)) { |
| 190 | reachableElements.add(nextAttribute); |
| 191 | } |
| 192 | |
| 193 | @SuppressWarnings("unchecked") |
| 194 | List<Element> nextElements = (List<Element>) DomUtils.getChildElementsByTagName(element, NEXT_ELE); |
| 195 | for (Element nextElement : nextElements) { |
| 196 | String toAttribute = nextElement.getAttribute(TO_ATTR); |
| 197 | reachableElements.add(toAttribute); |
| 198 | } |
| 199 | |
| 200 | @SuppressWarnings("unchecked") |
| 201 | List<Element> stopElements = (List<Element>) DomUtils.getChildElementsByTagName(element, STOP_ELE); |
| 202 | for (Element stopElement : stopElements) { |
| 203 | String restartAttribute = stopElement.getAttribute(RESTART_ATTR); |
| 204 | reachableElements.add(restartAttribute); |
| 205 | } |
| 206 | |
| 207 | return reachableElements; |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * Find all of the elements reachable from the startElement. |
| 212 | * |
| 213 | * @param startElement |
| 214 | * @param reachableElementMap |
| 215 | * @param accumulator a collection of reachable element names |
| 216 | */ |
| 217 | private void findAllReachableElements(String startElement, Map<String, Set<String>> reachableElementMap, |
| 218 | Set<String> accumulator) { |
| 219 | Set<String> reachableIds = reachableElementMap.get(startElement); |
| 220 | accumulator.add(startElement); |
| 221 | if (reachableIds != null) { |
| 222 | for (String reachable : reachableIds) { |
| 223 | // don't explore a previously explored element; prevent loop |
| 224 | if (!accumulator.contains(reachable)) { |
| 225 | findAllReachableElements(reachable, reachableElementMap, accumulator); |
| 226 | } |
| 227 | } |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * @param parserContext the parser context for the bean factory |
| 233 | * @param stateDef The bean definition for the current state |
| 234 | * @param element the <step/gt; element to parse |
| 235 | * @return a collection of |
| 236 | * {@link org.springframework.batch.core.job.flow.support.StateTransition} |
| 237 | * references |
| 238 | */ |
| 239 | protected static Collection<BeanDefinition> getNextElements(ParserContext parserContext, BeanDefinition stateDef, |
| 240 | Element element) { |
| 241 | return getNextElements(parserContext, null, stateDef, element); |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * @param parserContext the parser context for the bean factory |
| 246 | * @param stepId the id of the current state if it is a step state, null |
| 247 | * otherwise |
| 248 | * @param stateDef The bean definition for the current state |
| 249 | * @param element the <step/gt; element to parse |
| 250 | * @return a collection of |
| 251 | * {@link org.springframework.batch.core.job.flow.support.StateTransition} |
| 252 | * references |
| 253 | */ |
| 254 | protected static Collection<BeanDefinition> getNextElements(ParserContext parserContext, String stepId, |
| 255 | BeanDefinition stateDef, Element element) { |
| 256 | |
| 257 | Collection<BeanDefinition> list = new ArrayList<BeanDefinition>(); |
| 258 | |
| 259 | String shortNextAttribute = element.getAttribute(NEXT_ATTR); |
| 260 | boolean hasNextAttribute = StringUtils.hasText(shortNextAttribute); |
| 261 | if (hasNextAttribute) { |
| 262 | list.add(getStateTransitionReference(parserContext, stateDef, null, shortNextAttribute)); |
| 263 | } |
| 264 | |
| 265 | boolean transitionElementExists = false; |
| 266 | List<String> patterns = new ArrayList<String>(); |
| 267 | for (String transitionName : new String[] { NEXT_ELE, STOP_ELE, END_ELE, FAIL_ELE }) { |
| 268 | @SuppressWarnings("unchecked") |
| 269 | List<Element> transitionElements = (List<Element>) DomUtils.getChildElementsByTagName(element, |
| 270 | transitionName); |
| 271 | for (Element transitionElement : transitionElements) { |
| 272 | verifyUniquePattern(transitionElement, patterns, element, parserContext); |
| 273 | list.addAll(parseTransitionElement(transitionElement, stepId, stateDef, parserContext)); |
| 274 | transitionElementExists = true; |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | if (!transitionElementExists) { |
| 279 | list.addAll(createTransition(FlowExecutionStatus.FAILED, FlowExecutionStatus.FAILED.getName(), null, null, |
| 280 | stateDef, parserContext, false)); |
| 281 | if (!hasNextAttribute) { |
| 282 | list.addAll(createTransition(FlowExecutionStatus.COMPLETED, null, null, null, stateDef, parserContext, |
| 283 | false)); |
| 284 | } |
| 285 | } |
| 286 | else if (hasNextAttribute) { |
| 287 | parserContext.getReaderContext().error( |
| 288 | "The <" + element.getNodeName() + "/> may not contain a '" + NEXT_ATTR |
| 289 | + "' attribute and a transition element", element); |
| 290 | } |
| 291 | |
| 292 | return list; |
| 293 | } |
| 294 | |
| 295 | /** |
| 296 | * @param transitionElement The element to parse |
| 297 | * @param patterns a list of patterns on state transitions for this element |
| 298 | * @param element |
| 299 | * @param parserContext the parser context for the bean factory |
| 300 | */ |
| 301 | private static void verifyUniquePattern(Element transitionElement, List<String> patterns, Element element, |
| 302 | ParserContext parserContext) { |
| 303 | String onAttribute = transitionElement.getAttribute(ON_ATTR); |
| 304 | if (patterns.contains(onAttribute)) { |
| 305 | parserContext.getReaderContext().error("Duplicate transition pattern found for '" + onAttribute + "'", |
| 306 | element); |
| 307 | } |
| 308 | patterns.add(onAttribute); |
| 309 | } |
| 310 | |
| 311 | /** |
| 312 | * @param transitionElement The element to parse |
| 313 | * @param stateDef The bean definition for the current state |
| 314 | * @param parserContext the parser context for the bean factory |
| 315 | * @param a collection of |
| 316 | * {@link org.springframework.batch.core.job.flow.support.StateTransition} |
| 317 | * references |
| 318 | */ |
| 319 | private static Collection<BeanDefinition> parseTransitionElement(Element transitionElement, String stateId, |
| 320 | BeanDefinition stateDef, ParserContext parserContext) { |
| 321 | |
| 322 | FlowExecutionStatus status = getBatchStatusFromEndTransitionName(transitionElement.getNodeName()); |
| 323 | String onAttribute = transitionElement.getAttribute(ON_ATTR); |
| 324 | String restartAttribute = transitionElement.getAttribute(RESTART_ATTR); |
| 325 | String nextAttribute = transitionElement.getAttribute(TO_ATTR); |
| 326 | if (!StringUtils.hasText(nextAttribute)) { |
| 327 | nextAttribute = restartAttribute; |
| 328 | } |
| 329 | boolean abandon = stateId != null && StringUtils.hasText(restartAttribute) && !restartAttribute.equals(stateId); |
| 330 | String exitCodeAttribute = transitionElement.getAttribute(EXIT_CODE_ATTR); |
| 331 | |
| 332 | return createTransition(status, onAttribute, nextAttribute, exitCodeAttribute, stateDef, parserContext, abandon); |
| 333 | } |
| 334 | |
| 335 | /** |
| 336 | * @param status The batch status that this transition will set. Use |
| 337 | * BatchStatus.UNKNOWN if not applicable. |
| 338 | * @param on The pattern that this transition should match. Use null for |
| 339 | * "no restriction" (same as "*"). |
| 340 | * @param next The state to which this transition should go. Use null if not |
| 341 | * applicable. |
| 342 | * @param exitCode The exit code that this transition will set. Use null to |
| 343 | * default to batchStatus. |
| 344 | * @param stateDef The bean definition for the current state |
| 345 | * @param parserContext the parser context for the bean factory |
| 346 | * @param a collection of |
| 347 | * {@link org.springframework.batch.core.job.flow.support.StateTransition} |
| 348 | * references |
| 349 | */ |
| 350 | private static Collection<BeanDefinition> createTransition(FlowExecutionStatus status, String on, String next, |
| 351 | String exitCode, BeanDefinition stateDef, ParserContext parserContext, boolean abandon) { |
| 352 | |
| 353 | BeanDefinition endState = null; |
| 354 | |
| 355 | // TODO: revise this for clarity |
| 356 | if (status == FlowExecutionStatus.STOPPED || status == FlowExecutionStatus.COMPLETED |
| 357 | || status == FlowExecutionStatus.FAILED) { |
| 358 | |
| 359 | BeanDefinitionBuilder endBuilder = BeanDefinitionBuilder |
| 360 | .genericBeanDefinition("org.springframework.batch.core.job.flow.support.state.EndState"); |
| 361 | |
| 362 | boolean exitCodeExists = StringUtils.hasText(exitCode); |
| 363 | |
| 364 | endBuilder.addConstructorArgValue(status); |
| 365 | |
| 366 | endBuilder.addConstructorArgValue(exitCodeExists ? exitCode : status.getName()); |
| 367 | |
| 368 | String endName = (status == FlowExecutionStatus.STOPPED ? STOP_ELE |
| 369 | : status == FlowExecutionStatus.FAILED ? FAIL_ELE : END_ELE) |
| 370 | + (endCounter++); |
| 371 | endBuilder.addConstructorArgValue(endName); |
| 372 | |
| 373 | endBuilder.addConstructorArgValue(abandon); |
| 374 | |
| 375 | String nextOnEnd = exitCodeExists ? null : next; |
| 376 | endState = getStateTransitionReference(parserContext, endBuilder.getBeanDefinition(), null, nextOnEnd); |
| 377 | next = endName; |
| 378 | |
| 379 | } |
| 380 | |
| 381 | Collection<BeanDefinition> list = new ArrayList<BeanDefinition>(); |
| 382 | list.add(getStateTransitionReference(parserContext, stateDef, on, next)); |
| 383 | if (endState != null) { |
| 384 | // |
| 385 | // Must be added after the state to ensure that the state is the |
| 386 | // first in the list |
| 387 | // |
| 388 | list.add(endState); |
| 389 | } |
| 390 | return list; |
| 391 | } |
| 392 | |
| 393 | /** |
| 394 | * @param elementName An end transition element name |
| 395 | * @return the BatchStatus corresponding to the transition name |
| 396 | */ |
| 397 | private static FlowExecutionStatus getBatchStatusFromEndTransitionName(String elementName) { |
| 398 | if (STOP_ELE.equals(elementName)) { |
| 399 | return FlowExecutionStatus.STOPPED; |
| 400 | } |
| 401 | else if (END_ELE.equals(elementName)) { |
| 402 | return FlowExecutionStatus.COMPLETED; |
| 403 | } |
| 404 | else if (FAIL_ELE.equals(elementName)) { |
| 405 | return FlowExecutionStatus.FAILED; |
| 406 | } |
| 407 | else { |
| 408 | return FlowExecutionStatus.UNKNOWN; |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * @param parserContext the parser context |
| 414 | * @param stateDefinition a reference to the state implementation |
| 415 | * @param on the pattern value |
| 416 | * @param next the next step id |
| 417 | * @return a bean definition for a |
| 418 | * {@link org.springframework.batch.core.job.flow.support.StateTransition} |
| 419 | */ |
| 420 | public static BeanDefinition getStateTransitionReference(ParserContext parserContext, |
| 421 | BeanDefinition stateDefinition, String on, String next) { |
| 422 | |
| 423 | BeanDefinitionBuilder nextBuilder = BeanDefinitionBuilder |
| 424 | .genericBeanDefinition("org.springframework.batch.core.job.flow.support.StateTransition"); |
| 425 | nextBuilder.addConstructorArgValue(stateDefinition); |
| 426 | |
| 427 | if (StringUtils.hasText(on)) { |
| 428 | nextBuilder.addConstructorArgValue(on); |
| 429 | } |
| 430 | |
| 431 | if (StringUtils.hasText(next)) { |
| 432 | nextBuilder.setFactoryMethod("createStateTransition"); |
| 433 | nextBuilder.addConstructorArgValue(next); |
| 434 | } |
| 435 | else { |
| 436 | nextBuilder.setFactoryMethod("createEndStateTransition"); |
| 437 | } |
| 438 | |
| 439 | return nextBuilder.getBeanDefinition(); |
| 440 | |
| 441 | } |
| 442 | |
| 443 | } |