Java 类com.amazonaws.services.dynamodbv2.model.AmazonDynamoDBException 实例源码

public static void main(String[] args)
{
    final String USAGE = "\n" +
            "Usage:\n" +
            "    Query <table> <partitionkey> <partitionkeyvalue>\n\n" +
            "Where:\n" +
            "    table - the table to put the item in.\n" +
            "    partitionkey  - partition key name of the table.\n" +
            "    partitionkeyvalue - value of the partition key that should match.\n\n" +
            "Example:\n" +
            "    Query GreetingsTable Language eng \n";

    if (args.length < 3) {
        System.out.println(USAGE);
        System.exit(1);
    }

    String table_name = args[0];
    String partition_key_name = args[1];
    String partition_key_val = args[2];
    String partition_alias = "#a";

    System.out.format("Querying %s", table_name);
    System.out.println("");

    final AmazonDynamoDB ddb = AmazonDynamoDBClientBuilder.defaultClient();

    //set up an alias for the partition key name in case it's a reserved word
    HashMap<String,String> attrNameAlias =
            new HashMap<String,String>();
    attrNameAlias.put(partition_alias, partition_key_name);

    //set up mapping of the partition name with the value
    HashMap<String, AttributeValue> attrValues =
            new HashMap<String,AttributeValue>();
    attrValues.put(":"+partition_key_name, new AttributeValue().withS(partition_key_val));

    QueryRequest queryReq = new QueryRequest()
            .withTableName(table_name)
            .withKeyConditionExpression(partition_alias + " = :" + partition_key_name)
            .withExpressionAttributeNames(attrNameAlias)
            .withExpressionAttributeValues(attrValues);

    try {
        QueryResult response = ddb.query(queryReq);
        System.out.println(response.getCount());
    } catch (AmazonDynamoDBException e) {
        System.err.println(e.getErrorMessage());
        System.exit(1);
    }
    System.out.println("Done!");
}