amazon-web-services - 由于命名约定，使用 DynamoDB AWS SDK [No Mapping for Hash Key] 时出错

Question

在使用 AWS JAva SDK 时，我们使用 @DynamoDBHashKey 注释来定义 DynamoDBHashKey。

奇怪的是，如果我使用如下注释

@DynamoDBHashKey 
String Abc

代替

@DynamoDBHashKey 
String abc

this gives me an error, no mapping for HASH key [junit] at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperTableModel.hashKey(DynamoDBMapperTableModel.java:119) [junit] at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperTableModel$Builder.build(DynamoDBMapperTableModel.java:449) [junit] at com.amazonaws.services.dynamodbv2.datamodeling.StandardModelFactories$StandardTableFactory.getTable(StandardModelFactories.java:104) [junit] at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.getTableModel(DynamoDBMapper.java:393) [junit] at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.generateCreateTableRequest(DynamoDBMapper.java:2148) [junit] at com.amazonaws.services.dynamodbv2.datamodeling.AbstractDynamoDBMapper.generateCreateTableRequest(AbstractDynamoDBMapper.java:319)

我无法理解为什么变量命名约定在失败中起作用任何想法？

Answer 1

内省(introspection)魔法在这种情况下似乎不起作用。 Force the attribute name使用参数 attributeName。

@DynamoDBTable(tableName="Books")
public static class Book {
    private String Abc;

    @DynamoDBHashKey(attributeName="Abc")
    public int getAbc() {
        return Abc;
    }
}