仅使用 hashKey 查询 dynamoDB

我想仅使用 Hashkey 查询我的 dynamoDB。 我的表（名称= testTable）架构如下：

• 字符串自动ID（HashKey）
• 字符串 AlexandriaID (RangeKey)
• 字符串文档类型

我的 dynamoDBQueryExpression 是：

String hashKey = "dummyHashKey";

testTable hashKeyValues = new testTable();

hashKeyValues.setAutoID(hashKey);

DynamoDBQueryExpression<testTable> queryExpression = new DynamoDBQueryExpression<testTable>();
queryExpression.withHashKeyValues(hashKeyValues);

//Assuming I have a dynamoDBMapper object mapper

List<testTable> docList = mapper.query(testTable.class, queryExpression);

我期待一个具有相同 autoID 的 testTable 对象列表。由于我是新手，如果我错了，请纠正我。

当我做的时候什么也没有发生mapper.query() call.

参考 Vikdor 在 StackOverflow 问题上的评论在 dynamoDB 中使用 hashKey 进行查询 https://stackoverflow.com/questions/30969594/query-all-items-in-dynamodb-from-a-given-hash-key-with-a-hash-range-schema-using

进一步编辑：

我的确切查询方法：

public void queryFromRFIDocumentDetails(String hashKey){
    System.out.println((new Throwable()).getStackTrace()[0].toString() + "***Enter***");

    testTable hashKeyValues = new testTable();
    hashKeyValues.setAutoID(hashKey);

    System.out.println("AutoID for hashKeyValues " + hashKeyValues.getAutoID());
    System.out.println("DocTYpe for hashKeyValues " + hashKeyValues.getDocType());
    System.out.println("AlexandriaID for hashKeyValues " + hashKeyValues.getAlexandraiID());

    DynamoDBQueryExpression<testTable> queryExpression = new DynamoDBQueryExpression<testTable>();
    queryExpression.withHashKeyValues(hashKeyValues);
    queryExpression.withConsistentRead(false);

    System.out.println("calling mapper.query");  //nothing happens after this

    List<testTable> docList = new ArrayList<testTable>();
    docList = mapper.query(testTable.class, queryExpression);

    for(int i=0; i<docList.size(); i++){
        System.out.println("***iterating at retrieved index " + i);
        System.out.println("AutoID for retrieved document " + docList.get(i).getAutoID());
        System.out.println("DocTYpe for retrieved document " + docList.get(i).getDocType());
        System.out.println("AlexandriaID for retrieved document " + docList.get(i).getAlexandraiID());
    }
}

我的程序的堆栈跟踪：

调用方法保存表中的对象：

***iterating at index 0
[java] AutoID for document to be saved abc
[java] DocTYpe for document to be saved foo
[java] AlexandriaID for document to be saved id1
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:201)***Enter***
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:203)***Exit***
[java] ***iterating at index 1
[java] AutoID for document to be saved abc
[java] DocTYpe for document to be saved foo
[java] AlexandriaID for document to be saved id2
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:201)***Enter***
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:203)***Exit***
[java] ***iterating at index 2
[java] AutoID for document to be saved abc
[java] DocTYpe for document to be saved foo
[java] AlexandriaID for document to be saved id3
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:201)***Enter***
[java] com.amazon.sduservice.db.dynamoDB.saveInRFIDocumentDetails(dynamoDB.java:203)***Exit***
[java] hashKey is abc

根据autoID查询表的调用方法：

[java] com.amazon.sduservice.db.dynamoDB.queryFromRFIDocumentDetails(dynamoDB.java:207)***Enter***
[java] AutoID for hashKeyValues abc
[java] DocTYpe for hashKeyValues null
[java] AlexandriaID for hashKeyValues null
[java] calling mapper.query

扫描表上的操作输出：

Scanning Table RFIDocumentDetails
 [java] {docType={S: foo,}, autoID={S: abc,}, alexandriaID={S: id1,}}
 [java] {docType={S: foo,}, autoID={S: abc,}, alexandriaID={S: id2,}}
 [java] {docType={S: foo,}, autoID={S: abc,}, alexandriaID={S: id3,}}
 [java] {docType={S: pdf,}, autoID={S: HashKey,}, alexandriaID={S: alexandriaID1,}}
 [java] {docType={S: pdf,}, autoID={S: HashKey,}, alexandriaID={S: alexandriaID2,}}
 [java] {docType={S: foo,}, autoID={S: asdf,}, alexandriaID={S: id1,}}
 [java] {docType={S: foo,}, autoID={S: asdf,}, alexandriaID={S: id2,}}
 [java] {docType={S: foo,}, autoID={S: foo,}, alexandriaID={S: id1,}}
 [java] {docType={S: foo,}, autoID={S: foo,}, alexandriaID={S: id2,}}
 [java] Scanning Table Finishes 

测试表类：

public class testTable {    
   private String autoID;   
   private String docType;  
   private String alexandriaID;     

   @DynamoDBHashKey(attributeName="autoID") 
   public String getAutoID(){   return autoID;} 
   public void setAutoID(String autoID){    this.autoID = autoID;}      

   @DynamoDBRangeKey(attributeName="alexandriaID")  
   public String getAlexandraiID(){ return alexandriaID;}   
   public void setAlexandriaID(String alexandriaID){    this.alexandriaID = alexandriaID;}      

   @DynamoDBAttribute(attributeName="docType")  
   public String getDocType(){  return docType;}    
   public void setDocType(String docType){  this.docType = docType;}    

}

正如所讨论的，问题似乎出在 getAlexandraiID 声明中。

请更改方法名称，如下所述：-

From:-

public String getAlexandraiID(){ return alexandriaID;} 

To:-

@DynamoDBRangeKey(attributeName = "alexandriaID")
public String getAlexandriaID() {
    return alexandriaID;
}