Update SpringBootBatch源码.md

docs/SpringBootBatch/SpringBootBatch源码.md

@@ -5,7 +5,6 @@
 版本使用 2.7.13
 
 ```xml
-
 <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-dependencies</artifactId>
@@ -237,7 +236,7 @@ public ExitStatus afterStep(StepExecution stepExecution){
 中有个`protected final CommonStepProperties properties;`属性。
 对`CommonStepProperties`中`name`，`JobRepository`和`PlatformTransactionManager`进行赋值。
 
-#### .<Integer, Integer>chunk(2)
+#### <Integer, Integer>chunk(2)
 
 ```java
 /**
@@ -306,7 +305,6 @@ public void write(List<?extends Integer> items){
             System.out.println("一次读取：" + Arrays.toString(items.toArray()));
         }
     };
-
 }
 ```
 
@@ -393,8 +391,7 @@ public TaskletStep build(){
 
     try {
         step.afterPropertiesSet();
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         throw new StepBuilderException(e);
     }
 
@@ -563,8 +560,7 @@ public SimpleJobBuilder start(Step step){
     job.setSteps(steps);
     try {
         job.afterPropertiesSet();
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         throw new JobBuilderException(e);
     }
     return job;
@@ -628,7 +624,6 @@ public SimpleJobBuilder start(Step step){
 也是使用这个`JobLauncherApplicationRunner#executeRegisteredJobs(JobParameters jobParameters)`。
 
 ```java
-
 @RestController
 public class BatchController {
 
@@ -721,8 +716,7 @@ public JobExecution createJobExecution(String jobName,JobParameters jobParameter
             }
         }
         executionContext = ecDao.getExecutionContext(jobExecutionDao.getLastJobExecution(jobInstance));
-        }
+    } else {
-        else{
         // no job found, create one
         jobInstance = jobInstanceDao.createJobInstance(jobName, jobParameters);
         executionContext = new ExecutionContext();
@@ -818,23 +812,21 @@ public void updateExecutionContext(JobExecution jobExecution){
         public void run() {
             try {
                 job.execute(jobExecution);
-        }
+            } catch (Throwable t) {
-        catch(Throwable t){
                 rethrow(t);
             }
         }
+
         private void rethrow(Throwable t) {
             if (t instanceof RuntimeException) {
                 throw (RuntimeException) t;
-        }
+            } else if (t instanceof Error) {
-        else if(t instanceof Error){
                 throw (Error) t;
             }
             throw new IllegalStateException(t);
         }
     });
-        }
+} catch (TaskRejectedException e) {
-        catch(TaskRejectedException e){
     jobExecution.upgradeStatus(BatchStatus.FAILED);
     if (jobExecution.getExitStatus().equals(ExitStatus.UNKNOWN)) {
         jobExecution.setExitStatus(ExitStatus.FAILED.addExitDescription(e));
@@ -1243,16 +1235,14 @@ public StepExecution handleStep(Step step,JobExecution execution)throws JobInter
             if (lastStepExecution.getExecutionContext().containsKey("batch.executed")) {
                 currentStepExecution.getExecutionContext().remove("batch.executed");
             }
-        }
+        } else {
-        else{
             currentStepExecution.setExecutionContext(new ExecutionContext(executionContext));
         }
         jobRepository.add(currentStepExecution);
         try {
             step.execute(currentStepExecution);
             currentStepExecution.getExecutionContext().put("batch.executed", true);
-        }
+        } catch (JobInterruptedException e) {
-        catch(JobInterruptedException e){
             execution.setStatus(BatchStatus.STOPPING);
             throw e;
         }
@@ -1334,8 +1324,7 @@ protected boolean shouldStart(StepExecution lastStepExecution,JobExecution jobEx
     BatchStatus stepStatus;
     if (lastStepExecution == null) {
         stepStatus = BatchStatus.STARTING;
-        }
+    } else {
-        else{
         stepStatus = lastStepExecution.getStatus();
     }
 
@@ -1358,8 +1347,7 @@ protected boolean shouldStart(StepExecution lastStepExecution,JobExecution jobEx
     if (jobRepository.getStepExecutionCount(jobExecution.getJobInstance(), step.getName()) < step.getStartLimit()) {
         // step start count is less than start max, return true
         return true;
-        }
+    } else {
-        else{
         // start max has been exceeded, throw an exception.
         throw new StartLimitExceededException("Maximum start limit exceeded for step: " + step.getName()
                 + "StartMax: " + step.getStartLimit());
@@ -1463,6 +1451,7 @@ public void saveStepExecution(StepExecution stepExecution){
 public void saveExecutionContext(StepExecution stepExecution) {
     updateExecutionContext(stepExecution);
 }
+
 @Override
 public void updateExecutionContext(StepExecution stepExecution) {
     ExecutionContext executionContext = stepExecution.getExecutionContext();
@@ -1510,8 +1499,7 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
 
         try {
             doExecute(stepExecution);
-        }
+        } catch (RepeatException e) {
-        catch(RepeatException e){
             throw e.getCause();
         }
         exitStatus = ExitStatus.COMPLETED.and(stepExecution.getExitStatus());
@@ -1526,8 +1514,7 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
         if (logger.isDebugEnabled()) {
             logger.debug("Step execution success: id=" + stepExecution.getId());
         }
-        }
+    } catch (Throwable e) {
-        catch(Throwable e){
         stepExecution.upgradeStatus(determineBatchStatus(e));
         exitStatus = exitStatus.and(getDefaultExitStatusForFailure(e));
         stepExecution.addFailureException(e);
@@ -1536,12 +1523,10 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
             if (logger.isDebugEnabled()) {
                 logger.debug("Full exception", e);
             }
-        }
+        } else {
-        else{
             logger.error(String.format("Encountered an error executing step %s in job %s", name, stepExecution.getJobExecution().getJobInstance().getJobName()), e);
         }
-        }
+    } finally {
-        finally{
 
         try {
             // Update the step execution to the latest known value so the
@@ -1549,15 +1534,13 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
             exitStatus = exitStatus.and(stepExecution.getExitStatus());
             stepExecution.setExitStatus(exitStatus);
             exitStatus = exitStatus.and(getCompositeListener().afterStep(stepExecution));
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             logger.error(String.format("Exception in afterStep callback in step %s in job %s", name, stepExecution.getJobExecution().getJobInstance().getJobName()), e);
         }
 
         try {
             getJobRepository().updateExecutionContext(stepExecution);
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             stepExecution.setStatus(BatchStatus.UNKNOWN);
             exitStatus = exitStatus.and(ExitStatus.UNKNOWN);
             stepExecution.addFailureException(e);
@@ -1578,8 +1561,7 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
         }
         try {
             getJobRepository().update(stepExecution);
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             stepExecution.setStatus(BatchStatus.UNKNOWN);
             stepExecution.setExitStatus(exitStatus.and(ExitStatus.UNKNOWN));
             stepExecution.addFailureException(e);
@@ -1589,8 +1571,7 @@ public final void execute(StepExecution stepExecution)throws JobInterruptedExcep
 
         try {
             close(stepExecution.getExecutionContext());
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             logger.error(String.format("Exception while closing step execution resources in step %s in job %s", name, stepExecution.getJobExecution().getJobInstance().getJobName()), e);
             stepExecution.addFailureException(e);
         }
@@ -1708,8 +1689,7 @@ public RepeatStatus doInChunkContext(RepeatContext repeatContext,ChunkContext ch
             try {
                 result = new TransactionTemplate(transactionManager, transactionAttribute)
                         .execute(new ChunkTransactionCallback(chunkContext, semaphore));
-        }
+            } catch (UncheckedTransactionException e) {
-        catch(UncheckedTransactionException e){
                 throw (Exception) e.getCause();
             }
             chunkListener.afterChunk(chunkContext);
@@ -1755,8 +1735,7 @@ public RepeatStatus iterate(RepeatCallback callback){
         // This works with an asynchronous TaskExecutor: the
         // interceptors have to wait for the child processes.
         result = executeInternal(callback);
-        }
+    } finally {
-        finally{
         RepeatSynchronizationManager.clear();
         if (outer != null) {
             RepeatSynchronizationManager.register(outer);
@@ -1820,8 +1799,7 @@ public RepeatStatus iterate(RepeatCallback callback){
                     result = getNextResult(context, callback, state);
                     executeAfterInterceptors(context, result);
 
-        }
+                } catch (Throwable throwable) {
-        catch(Throwable throwable){
                     doHandle(throwable, context, deferred);
                 }
 
@@ -1845,8 +1823,7 @@ public RepeatStatus iterate(RepeatCallback callback){
      * No need for explicit catch here - if the business processing threw an
      * exception it was already handled by the helper methods. An exception
      * here is necessarily fatal.
-         */
+     */ finally {
-        finally{
         try {
             if (!deferred.isEmpty()) {
                 Throwable throwable = deferred.iterator().next();
@@ -1856,15 +1833,13 @@ public RepeatStatus iterate(RepeatCallback callback){
                 }
                 rethrow(throwable);
             }
-        }
+        } finally {
-        finally{
             try {
                 for (int i = listeners.length; i-- > 0; ) {
                     RepeatListener interceptor = listeners[i];
                     interceptor.close(context);
                 }
-        }
+            } finally {
-        finally{
                 context.close();
             }
         }
@@ -1881,7 +1856,6 @@ public RepeatStatus iterate(RepeatCallback callback){
  *
  * @return a {@link RepeatContext} object that can be used by the implementation to store
  * internal state for a batch step.
- *
  * @see org.springframework.batch.repeat.CompletionPolicy#start(RepeatContext)
  */
 protected RepeatContext start() {
@@ -1991,8 +1965,7 @@ public RepeatStatus doInIteration(RepeatContext context)throws Exception{
             logger.debug("Chunk execution starting: queue size=" + attributeQueue.size());
         }
         return doInChunkContext(context, chunkContext);
-        }
+    } finally {
-        finally{
         // Still some stuff to do with the data in this chunk,
         // pass it back.
         if (!chunkContext.isComplete()) {
@@ -2026,8 +1999,7 @@ public RepeatStatus doInChunkContext(RepeatContext repeatContext,ChunkContext ch
     try {
         result = new TransactionTemplate(transactionManager, transactionAttribute)
                 .execute(new ChunkTransactionCallback(chunkContext, semaphore));
-        }
+    } catch (UncheckedTransactionException e) {
-        catch(UncheckedTransactionException e){
         // Allow checked exceptions to be thrown inside callback
         throw (Exception) e.getCause();
     }
@@ -2074,19 +2046,16 @@ public<T> T execute(TransactionCallback<T> action)throws TransactionException{
 
     if (this.transactionManager instanceof CallbackPreferringPlatformTransactionManager) {
         return ((CallbackPreferringPlatformTransactionManager) this.transactionManager).execute(this, action);
-        }
+    } else {
-        else{
         TransactionStatus status = this.transactionManager.getTransaction(this);
         T result;
         try {
             result = action.doInTransaction(status);
-        }
+        } catch (RuntimeException | Error ex) {
-        catch(RuntimeException|Error ex){
             // Transactional code threw application exception -> rollback
             rollbackOnException(status, ex);
             throw ex;
-        }
+        } catch (Throwable ex) {
-        catch(Throwable ex){
             // Transactional code threw unexpected exception -> rollback
             rollbackOnException(status, ex);
             throw new UndeclaredThrowableException(ex, "TransactionCallback threw undeclared checked exception");
@@ -2125,15 +2094,13 @@ public RepeatStatus doInTransaction(TransactionStatus status){
                 if (result == null) {
                     result = RepeatStatus.FINISHED;
                 }
-        }
+            } catch (Exception e) {
-        catch(Exception e){
                 if (transactionAttribute.rollbackOn(e)) {
                     chunkContext.setAttribute(ChunkListener.ROLLBACK_EXCEPTION_KEY, e);
                     throw e;
                 }
             }
-        }
+        } finally {
-        finally{
 
             // If the step operations are asynchronous then we need
             // to synchronize changes to the step execution (at a
@@ -2142,8 +2109,7 @@ public RepeatStatus doInTransaction(TransactionStatus status){
             try {
                 semaphore.acquire();
                 locked = true;
-        }
+            } catch (InterruptedException e) {
-        catch(InterruptedException e){
                 logger.error("Thread interrupted while locking for repository update");
                 stepExecution.setStatus(BatchStatus.STOPPED);
                 stepExecution.setTerminateOnly();
@@ -2172,30 +2138,26 @@ public RepeatStatus doInTransaction(TransactionStatus status){
                 logger.debug("Saving step execution before commit: " + stepExecution);
             }
             getJobRepository().update(stepExecution);
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             // If we get to here there was a problem saving the step
             // execution and we have to fail.
             String msg = "JobRepository failure forcing rollback";
             logger.error(msg, e);
             throw new FatalStepExecutionException(msg, e);
         }
-        }
+    } catch (Error e) {
-        catch(Error e){
         if (logger.isDebugEnabled()) {
             logger.debug("Rollback for Error: " + e.getClass().getName() + ": " + e.getMessage());
         }
         rollback(stepExecution);
         throw e;
-        }
+    } catch (RuntimeException e) {
-        catch(RuntimeException e){
         if (logger.isDebugEnabled()) {
             logger.debug("Rollback for RuntimeException: " + e.getClass().getName() + ": " + e.getMessage());
         }
         rollback(stepExecution);
         throw e;
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         if (logger.isDebugEnabled()) {
             logger.debug("Rollback for Exception: " + e.getClass().getName() + ": " + e.getMessage());
         }
@@ -2278,14 +2240,12 @@ public RepeatStatus doInIteration(final RepeatContext context)throws Exception{
             String status = BatchMetrics.STATUS_SUCCESS;
             try {
                 item = read(contribution, inputs);
-        }
+            } catch (SkipOverflowException e) {
-        catch(SkipOverflowException e){
                 // read() tells us about an excess of skips by throwing an
                 // exception
                 status = BatchMetrics.STATUS_FAILURE;
                 return RepeatStatus.FINISHED;
-        }
+            } finally {
-        finally{
                 stopTimer(sample, contribution.getStepExecution(), status);
             }
             if (item == null) {
@@ -2329,14 +2289,12 @@ public RepeatStatus doInIteration(final RepeatContext context)throws Exception{
             String status = BatchMetrics.STATUS_SUCCESS;
             try {
                 item = read(contribution, inputs);
-        }
+            } catch (SkipOverflowException e) {
-        catch(SkipOverflowException e){
                 // read() tells us about an excess of skips by throwing an
                 // exception
                 status = BatchMetrics.STATUS_FAILURE;
                 return RepeatStatus.FINISHED;
-        }
+            } finally {
-        finally{
                 stopTimer(sample, contribution.getStepExecution(), status);
             }
             if (item == null) {
@@ -2368,6 +2326,7 @@ public RepeatStatus doInIteration(final RepeatContext context)throws Exception{
 ```java
 /**
  * Surrounds the read call with listener callbacks.
+ *
  * @return the item or {@code null} if the data source is exhausted
  * @throws Exception is thrown if error occurs during read.
  */
@@ -2380,8 +2339,7 @@ protected final I doRead()throws Exception{
             listener.afterRead(item);
         }
         return item;
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         if (logger.isDebugEnabled()) {
             logger.debug(e.getMessage() + " : " + e.getClass().getName());
         }
@@ -2464,8 +2422,7 @@ final I item=iterator.next();
         String status = BatchMetrics.STATUS_SUCCESS;
         try {
             output = doProcess(item);
-        }
+        } catch (Exception e) {
-        catch(Exception e){
             /*
              * For a simple chunk processor (no fault tolerance) we are done
              * here, so prevent any more processing of these inputs.
@@ -2473,14 +2430,12 @@ final I item=iterator.next();
             inputs.clear();
             status = BatchMetrics.STATUS_FAILURE;
             throw e;
-        }
+        } finally {
-        finally{
             stopTimer(sample, contribution.getStepExecution(), "item.process", status, "Item processing");
         }
         if (output != null) {
             outputs.add(output);
-        }
+        } else {
-        else{
             iterator.remove();
         }
     }
@@ -2506,8 +2461,7 @@ final I item=iterator.next();
         O result = itemProcessor.process(item);
         listener.afterProcess(item, result);
         return result;
-                    }
+    } catch (Exception e) {
-                    catch(Exception e){
         listener.onProcessError(item, e);
         throw e;
     }
@@ -2547,8 +2501,7 @@ protected void write(StepContribution contribution,Chunk<I> inputs,Chunk<O> outp
     String status = BatchMetrics.STATUS_SUCCESS;
     try {
         doWrite(outputs.getItems());
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         /*
          * For a simple chunk processor (no fault tolerance) we are done
          * here, so prevent any more processing of these inputs.
@@ -2556,8 +2509,7 @@ protected void write(StepContribution contribution,Chunk<I> inputs,Chunk<O> outp
         inputs.clear();
         status = BatchMetrics.STATUS_FAILURE;
         throw e;
-        }
+    } finally {
-        finally{
         stopTimer(sample, contribution.getStepExecution(), "chunk.write", status, "Chunk writing");
     }
     contribution.incrementWriteCount(outputs.size());
@@ -2579,8 +2531,7 @@ protected void write(StepContribution contribution,Chunk<I> inputs,Chunk<O> outp
         listener.beforeWrite(items);
         writeItems(items);
         doAfterWrite(items);
-        }
+    } catch (Exception e) {
-        catch(Exception e){
         doOnWriteError(e, items);
         throw e;
     }
@@ -2786,6 +2737,4 @@ execution.upgradeStatus(stepExecution.getStatus());
 
 里面涉及到一大堆的监听器，处理器。每个类基本都有讲到。 类上的注释非常重要~！
 
-首先校验，然后使用`stepExecution`保存数据。ecDao 保存 ExecutionContext
+首先校验，然后使用`stepExecution`保存数据。ecDao 保存 ExecutionContext。
-
-## 完整代码示例在[github](https://github.com/poo0054/spring-boot-study/tree/master/spring-batch)