如何在基于 Java 的应用程序中为 DynamoDB 设置 TTL

Question

您好，我需要通过 AWS Java SDK 以编程方式为 DynamoDB 中的表设置时间。可能吗？我知道最近引入了TTL功能-http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html

更新： 没有特别的注释，但是我们可以手动做：

@DynamoDBAttribute
private long ttl;

并在 AWS 中将其配置为 ttl - http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/time-to-live-ttl-how-to.html

long now = Instant.now().getEpochSecond(); // unix time
long ttl = 60 * 60 * 24; // 24 hours in sec
setTtl(ttl + now); // when object will be expired

Answer 1

http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/time-to-live-ttl-how-to.html

    public void function(final AmazonDynamoDB client, final String tableName, final String ttlField){

        //table created now enabling TTL
        final UpdateTimeToLiveRequest req = new UpdateTimeToLiveRequest();
        req.setTableName(tableName);

        final TimeToLiveSpecification ttlSpec = new TimeToLiveSpecification();
        ttlSpec.setAttributeName(ttlField);
        ttlSpec.setEnabled(true);
        req.withTimeToLiveSpecification(ttlSpec);

        client.updateTimeToLive(req);
    }

Answer 2

AmazonDynamoDBClient.updateTimeToLive 记录here 或直接链接here

Answer 3

代码示例here。

  //Then set ttl field like below for days in java
    //ttl 60 days
    Calendar cal = Calendar.getInstance(); //current date and time      
    cal.add(Calendar.DAY_OF_MONTH, 60); //add days
    double ttl =  (cal.getTimeInMillis() / 1000L);