The constructor of JsonItemReader should call setExecutionContextName()

[benelog]

When the constructor of JsonItemReader is called directly and open(ExectionConext) is called, it makes exceptions at ExecutionContextUserSupport.getKey(..)

    JsonItemReader<AccessLog> reader = new JsonItemReader<AccessLog>(resource, jsonObjectReader);
    reader.open(new ExecutionContext());
    AccessLog item = reader.read();
    reader.close();

java.lang.IllegalArgumentException: Name must be assigned for the sake of defining the execution context keys prefix.

	at org.springframework.util.Assert.hasText(Assert.java:284)
	at org.springframework.batch.item.util.ExecutionContextUserSupport.getKey(ExecutionContextUserSupport.java:62)
	at org.springframework.batch.item.ItemStreamSupport.getExecutionContextKey(ItemStreamSupport.java:71)
	at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.open(AbstractItemCountingItemStreamItemReader.java:159)

The constructor of JsonItemReader should call setExecutionContextName(String) similar to JsonFileItemWriter.java#L71

[fmbenhassine]

Good catch. This is indeed enforced in the builder but not in the constructor. Thank you for raising this issue and for opening a PR! I will take a look asap.