由于命名约定，在使用DynamoDB AWS开发工具包时出现错误[没有哈希键映射] [英] Error while using DynamoDB AWS SDK [No Mapping for Hash Key] because of naming convention

问题描述

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

While using AWS JAva SDK, for defining DynamoDBHashKey we @DynamoDBHashKey annotation.

如果我使用以下注释，则很奇怪

@DynamoDBHashKey 
String Abc

而不是

@DynamoDBHashKey 
String abc

这给了我一个错误，
没有映射HASH键
[junit] com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperTableModel.hashKey（DynamoDBMapperTableModel.java:119）
[junit] at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperTableModel $ Builder.build（DynamoDB） com.amazonaws.services.dynamodbv2.datamodeling.StandardModelFactories $ StandardTableFactory.getTable（StandardModelFactories.java:104）上的
[junit] com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper上的
[junit]。 getTableModel（DynamoDBM apper.java:393）com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.generateCreateTableRequest（DynamoDBMapper.java:2148）
[junit] com.amazonaws.services.dynamodbv2。 datamodeling.AbstractDynamoDBMapper.generateCreateTableRequest（AbstractDynamoDBMapper.java:319）

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)

我不明白为什么变量命名约定会在失败中起作用有想法吗？

I am unable to understand why does variable naming convention plays a role in failure Any Idea?

推荐答案

在这种情况下，自省魔法似乎无效。 使用参数 attributeName 强制属性名称。

Introspection magic does not appear to be working in this case. Force the attribute name with the parameter attributeName.

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

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

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