Java DynamoDB 增加、刪除、修改、查詢

准備jar包

<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-core</artifactId>
    <version>1.11.534</version>
</dependency>
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-dynamodb</artifactId>
    <version>1.11.46</version>
</dependency>

准備對象：

//用戶憑證
private static String AWSAccessKeyId = "xxx";
private static String AWSSecretKey = "xxx";
//表名
private static String TABLE_NAME = "xxx";
//用戶憑證對象
private static AWSCredentialsProvider awsCredentialsProvider = new AWSCredentialsProvider() {
　　public void refresh() {}
　　public AWSCredentials getCredentials() {return new BasicAWSCredentials(AWSAccessKeyId, AWSSecretKey);}
};
//表的相關對象
private static AmazonDynamoDB amazonDynamoDBClient = null;
private static DynamoDBMapper dbMapper = null;
private static Table table = null;

數據庫表映射對象：

@DynamoDBTable(tableName = "xxx")
public class User {
    private String id = null;
    private String name = null;
    private String telephone = null;

    public User(String id, String name, String telephone) {
        super();
        this.id = id;
        this.name = name;
        this.telephone = telephone;
    }
　　//主鍵
    @DynamoDBHashKey(attributeName = "Id")
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public User() {
    }
　　//配有索引 userName-index
    @DynamoDBAttribute(attributeName = "userName")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
　　//配有索引 telephone-index
    @DynamoDBAttribute(attributeName = "telephone")
    public String getTelephone() {
        return telephone;
    }

    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
}        

初始化對象：

 

amazonDynamoDBClient =  AmazonDynamoDBClientBuilder.standard().withCredentials(awsCredentialsProvider).withRegion(Regions.AP_NORTHEAST_1).build();
dbMapper = new DynamoDBMapper(amazonDynamoDBClient);
table = new  DynamoDB(amazonDynamoDBClient).getTable(TABLE_NAME);

根據id查詢一條：

public static user getItemById(String id) {
        return dbMapper.load(User.class, id);
    }

根據指定索引查詢多條：

public static List<User> getItemBykey(String key, String value) {
　　　　//取索引
        Index index = table.getIndex(key + "-index");
        HashMap<String, String> nameMap = new HashMap<String, String>();
        nameMap.put("#key", key);
        HashMap<String, Object> valueMap = new HashMap<String, Object>();
        valueMap.put(":value", value);
　　　　//創建篩選條件，以map的形式傳入key和value，條件只能用 = 號，其他未考證
        QuerySpec querySpec = new QuerySpec().withKeyConditionExpression("#key = :value").withNameMap(nameMap)
                .withValueMap(valueMap);
        ItemCollection<QueryOutcome> items = index.query(querySpec);
        Iterator<Item> iterator = items.iterator();
        Item item = null;
        List<User> Users = new ArrayList<User>();
        while (iterator.hasNext()) {
            item = iterator.next();
            dashButtonUsers.add(new DashButtonUser(item.getString("Id"),item.getString("userName"),item.getString("telephone"));
        }
        return Users;
    }

根據指定條件掃描多條：

public static List<User> getItemByTimeRange(Long startTime, Long endTime) {
        Map<String, AttributeValue> expressionAttributeValues = new HashMap<String, AttributeValue>();
        expressionAttributeValues.put(":startTime", new AttributeValue().withN("" + startTime));
        expressionAttributeValues.put(":endTime", new AttributeValue().withN("" + endTime));
　　　　//篩選條件
        ScanRequest scanRequest = new ScanRequest().withTableName(TABLE_NAME)
                .withFilterExpression("startTime >= :startTime and endTime <= :endTime")
                .withExpressionAttributeValues(expressionAttributeValues);
        ScanResult result = amazonDynamoDBClient.scan(scanRequest);
        List<User> users = new ArrayList<User>();
        for (Map<String, AttributeValue> item : result.getItems()) {
                dashButtonUsers.add(new DashButtonUser(/* 略 */));
        }
        return users;
    }

根據id刪除：

//刪除一條
public static void deleteItemById(String id) {
    dbMapper.delete(new DashButtonUser(id, null, null, null, null, null, null));
    }
//刪除多條
public static void deleteBatch(List<User> ids) {
　　//ids[0] -->{"id":"xxx","telephone":null,"name":null}
    dbMapper.batchDelete(ids);
    }

添加、修改：

//添加、修改一條
public static void addOrupdateOneItem(User user) {
        dbMapper.save(user);
    }
//添加、修改多條
public static List<FailedBatch>  addOrUpdateBatch(List<User> users) {
        return dbMapper.batchSave(users);
    }