Java 类com.amazonaws.services.dynamodbv2.document.spec.UpdateItemSpec 实例源码

@Override
public void announce(long stateVersion) {
    Table table = dynamoDB.getTable(tableName);

    UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey("namespace", blobNamespace)
            .withUpdateExpression("set #version = :ver")
            .withNameMap(new NameMap().with("#version", "version"))
            .withValueMap(new ValueMap().withNumber(":ver", stateVersion));

    table.updateItem(updateItemSpec);
}

@Override
public UpdateItemBuilder<T> updateItem(Object hk, Object rk) {
    UpdateItemSpec spec = new UpdateItemSpec();
    if ( null != _rkName ) {
        spec.withPrimaryKey(_hkName, hk, _rkName, rk);
    } else {
        spec.withPrimaryKey(_hkName, hk);
    }
    return new UpdateItemBuilderImpl<T>(spec, this::updateItem, _clazz, _encryption, _convertValue);
}

private boolean updateItem(IndexKey key, String updateExpression, String conditionalExpression,
                           Map<String, String> expressionNames, Map<String, Object> expressionValues)
{
    try {
        updateItem(new UpdateItemSpec()
                   .withPrimaryKey(toPrimaryKey(key))
                   .withUpdateExpression(updateExpression)
                   .withConditionExpression(conditionalExpression)
                   .withNameMap(expressionNames)
                   .withValueMap(expressionValues));
        return true;
    } catch ( RollbackException ex ) {
        return false;
    }
}

private <V> V updateItem(UpdateItemSpec updateItemSpec, Class<V> type) {
    try {
        return maybeBackoff(false, () ->
                            fromItem(_encryption.decrypt(_updateItem.updateItem(updateItemSpec).getItem()), type));
    } catch ( ConditionalCheckFailedException ex ) {
        throw new RollbackException(ex);
    }
}

UpdateItemBuilderImpl(UpdateItemSpec spec, UpdateItem updateItem, Class<T> clazz, DDBEncryption encryption, ConvertValue convertValue) {
    _spec = spec;
    _updateItem = updateItem;
    _clazz = clazz;
    _encryption = encryption;
    _convertValue = convertValue;
}

public static void main(String[] args)  {

        AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        client.setEndpoint("http://localhost:8000");
        DynamoDB dynamoDB = new DynamoDB(client);

        Table table = dynamoDB.getTable("Movies");

        int year = 2015;
        String title = "The Big New Movie";

        // Conditional update (will fail)

        UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey(new PrimaryKey("year", 2015, "title",  "The Big New Movie"))
            .withUpdateExpression("remove info.actors[0]")
            .withConditionExpression("size(info.actors) > :num")
            .withValueMap(new ValueMap().withNumber(":num", 3));

        System.out.println("Attempting a conditional update...");
        try {
            table.updateItem(updateItemSpec);
            System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty());
        } catch (ConditionalCheckFailedException e) {
            e.printStackTrace();
            System.out.println("UpdateItem failed");
        }

    }

public static void main(String[] args)  {

        AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        client.setEndpoint("http://localhost:8000");
        DynamoDB dynamoDB = new DynamoDB(client);

        Table table = dynamoDB.getTable("Movies");

        int year = 2015;
        String title = "The Big New Movie";

        UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey("year", year, "title", title)
            .withUpdateExpression("set info.rating = info.rating + :val")
            .withValueMap(new ValueMap()
                .withNumber(":val", 1));

        System.out.println("Incrementing an atomic counter...");
        try {
            table.updateItem(updateItemSpec);
            System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty());
        } catch (Exception e) {
            System.out.println("UpdateItem failed");
            e.printStackTrace();
        }

    }

public static void main(String[] args)  {

        AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        client.setEndpoint("http://localhost:8000");
        DynamoDB dynamoDB = new DynamoDB(client);

        Table table = dynamoDB.getTable("Movies");

        int year = 2015;
        String title = "The Big New Movie";

        UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey("year", year, "title", title)
            .withUpdateExpression("set info.rating = :r, info.plot=:p, info.actors=:a")
            .withValueMap(new ValueMap()
                .withNumber(":r", 5.5)
                .withString(":p", "Everything happens all at once.")
                .withList(":a", Arrays.asList("Larry","Moe","Curly")));

        System.out.println("Updating the item...");
        try {
            table.updateItem(updateItemSpec);
            System.out.println("UpdateItem succeeded: " + table.getItem("year", year, "title", title).toJSONPretty());
        } catch (Exception e) {
            System.out.println("UpdateItem failed");
            e.printStackTrace();
        }


    }

private static void updateAddNewAttribute() {
    Table table = dynamoDB.getTable(tableName);

    try {

        Map<String, String> expressionAttributeNames = new HashMap<String, String>();
        expressionAttributeNames.put("#na", "NewAttribute");

        UpdateItemSpec updateItemSpec = new UpdateItemSpec()
        .withPrimaryKey("Id", 121)
        .withUpdateExpression("set #na = :val1")
        .withNameMap(new NameMap()
            .with("#na", "NewAttribute"))
        .withValueMap(new ValueMap()
            .withString(":val1", "Some value"))
        .withReturnValues(ReturnValue.ALL_NEW);

        UpdateItemOutcome outcome =  table.updateItem(updateItemSpec);

        // Check the response.
        System.out.println("Printing item after adding new attribute...");
        System.out.println(outcome.getItem().toJSONPretty());           

    }   catch (Exception e) {
        System.err.println("Failed to add new attribute in " + tableName);
        System.err.println(e.getMessage());
    }        
}

private static void updateMultipleAttributes() {

        Table table = dynamoDB.getTable(tableName);

        try {

           UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey("Id", 120)
            .withUpdateExpression("add #a :val1 set #na=:val2")
            .withNameMap(new NameMap()
                .with("#a", "Authors")
                .with("#na", "NewAttribute"))
            .withValueMap(new ValueMap()
                .withStringSet(":val1", "Author YY", "Author ZZ")
                .withString(":val2", "someValue"))
            .withReturnValues(ReturnValue.ALL_NEW);

            UpdateItemOutcome outcome = table.updateItem(updateItemSpec);

            // Check the response.
            System.out
            .println("Printing item after multiple attribute update...");
            System.out.println(outcome.getItem().toJSONPretty());

        } catch (Exception e) {
            System.err.println("Failed to update multiple attributes in "
                    + tableName);
            System.err.println(e.getMessage());

        }
    }

private static void updateExistingAttributeConditionally() {

        Table table = dynamoDB.getTable(tableName);

        try {

            // Specify the desired price (25.00) and also the condition (price =
            // 20.00)

            UpdateItemSpec updateItemSpec = new UpdateItemSpec()
            .withPrimaryKey("Id", 120)
            .withReturnValues(ReturnValue.ALL_NEW)
            .withUpdateExpression("set #p = :val1")
            .withConditionExpression("#p = :val2")
            .withNameMap(new NameMap()
                .with("#p", "Price"))
            .withValueMap(new ValueMap()
                .withNumber(":val1", 25)
                .withNumber(":val2", 20));

            UpdateItemOutcome outcome = table.updateItem(updateItemSpec);

            // Check the response.
            System.out
            .println("Printing item after conditional update to new attribute...");
            System.out.println(outcome.getItem().toJSONPretty());

        } catch (Exception e) {
            System.err.println("Error updating item in " + tableName);
            System.err.println(e.getMessage());
        }
    }

private T updateItem(UpdateItemSpec updateItemSpec) {
    return updateItem(updateItemSpec, _clazz);
}

public <V> V updateItem(UpdateItemSpec spec, Class<V> type);