java.lang.Object
- org.springframework.batch.item.ItemStreamSupport
- - org.springframework.batch.jsr.item.CheckpointSupport

所有已实现的接口:
ItemStream
直接已知子类:
ItemReaderAdapter, ItemWriterAdapter
```
public abstract class CheckpointSupport
extends ItemStreamSupport
```
Provides support for JSR-352 checkpointing. Checkpoint objects are copied prior to being added to the ExecutionContext for persistence by the framework. If the checkpoint object cannot be copied and further changes occur to the same instance, side effects may occur. In cases like this, it is recommended that a copy of the object being acted upon in the reader/writer is returned via the ItemReader.checkpointInfo() or ItemWriter.checkpointInfo() calls.
从以下版本开始:
3.0
作者:
Michael Minella

构造器概要
构造器
构造器说明
CheckpointSupport(java.lang.String checkpointKey)

方法概要

所有方法实例方法抽象方法具体方法
修饰符和类型	方法	说明
`void`	`close()`	No-op.
`protected abstract java.io.Serializable`	`doCheckpoint()`	Used to provide a `Serializable` representing the current state of the batch artifact.
`protected abstract void`	`doClose()`	Used to close the underlying batch artifact
`protected abstract void`	`doOpen(java.io.Serializable checkpoint)`	Used to open a batch artifact with previously saved checkpoint information.
`void`	`open(ExecutionContext executionContext)`	No-op.
`void`	`update(ExecutionContext executionContext)`	Return empty `ExecutionContext`.

从类继承的方法 org.springframework.batch.item.ItemStreamSupport
getExecutionContextKey, setExecutionContextName, setName

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - CheckpointSupport
```
public CheckpointSupport(java.lang.String checkpointKey)
```
    参数:
    checkpointKey - key to store the checkpoint object with in the ExecutionContext
- 方法详细资料
  - open
```
public void open(ExecutionContext executionContext)
          throws ItemStreamException
```
    从类复制的说明: ItemStreamSupport
    No-op.
    指定者:
    open 在接口中 ItemStream
    覆盖:
    open 在类中 ItemStreamSupport
    参数:
    executionContext - current step's ExecutionContext. Will be the executionContext from the last run of the step on a restart.
    抛出:
    ItemStreamException
    另请参阅:
    ItemStream.open(ExecutionContext)
  - doOpen
```
protected abstract void doOpen(java.io.Serializable checkpoint)
                        throws java.lang.Exception
```
    Used to open a batch artifact with previously saved checkpoint information.
    参数:
    checkpoint - previously saved checkpoint object
    抛出:
    java.lang.Exception - thrown by the implementation
  - update
```
public void update(ExecutionContext executionContext)
            throws ItemStreamException
```
    从类复制的说明: ItemStreamSupport
    Return empty ExecutionContext.
    指定者:
    update 在接口中 ItemStream
    覆盖:
    update 在类中 ItemStreamSupport
    参数:
    executionContext - to be updated
    抛出:
    ItemStreamException
    另请参阅:
    ItemStream.update(ExecutionContext)
  - doCheckpoint
```
protected abstract java.io.Serializable doCheckpoint()
                                              throws java.lang.Exception
```
    Used to provide a Serializable representing the current state of the batch artifact.
    返回:
    the current state of the batch artifact
    抛出:
    java.lang.Exception - thrown by the implementation
  - close
```
public void close()
           throws ItemStreamException
```
    从类复制的说明: ItemStreamSupport
    No-op.
    指定者:
    close 在接口中 ItemStream
    覆盖:
    close 在类中 ItemStreamSupport
    抛出:
    ItemStreamException
    另请参阅:
    ItemStream.close()
  - doClose
```
protected abstract void doClose()
                         throws java.lang.Exception
```
    Used to close the underlying batch artifact
    抛出:
    java.lang.Exception - thrown by the underlying implementation

类 CheckpointSupport

构造器概要

方法概要

从类继承的方法 org.springframework.batch.item.ItemStreamSupport

从类继承的方法 java.lang.Object

构造器详细资料

CheckpointSupport

方法详细资料

open

doOpen

update

doCheckpoint

close

doClose