Example usage for com.amazonaws.services.dynamodbv2.model ScanRequest withExpressionAttributeNames

Introduction

In this page you can find the example usage for com.amazonaws.services.dynamodbv2.model ScanRequest withExpressionAttributeNames.

Prototype

public ScanRequest withExpressionAttributeNames(java.util.Map<String, String> expressionAttributeNames) 

Source Link

Document

One or more substitution tokens for attribute names in an expression.

Usage

From source file:com.eho.dynamodb.DynamoDBConnection.java

public static ScanResult scan_dynamodb(Map<String, String> strings, Map<String, String> numbers) {
    Map<String, AttributeValue> expression_values = new HashMap<>();
    Map<String, String> expression_names = new HashMap<>();

    if (strings.keySet().contains("#jsondocument.#name[0].given[0]")
            | strings.keySet().contains("#jsondocument.#name[0].#family[0]"))
        expression_names.put("#name", "name");

    if (strings.keySet().contains("#jsondocument.#name[0].#family[0]"))
        expression_names.put("#family", "family");

    expression_names.put("#jsondocument", "json-document");

    ScanRequest scanRequest = new ScanRequest().withTableName(DynamoDBConnection.PATIENT_TABLE);

    int i = 0;/* ww  w .j a v  a2  s  .  co  m*/
    String filter_expression = "";
    for (String path : strings.keySet()) {
        String thisVal = strings.get(path);
        expression_values.put(":stringval" + i, new AttributeValue().withS(thisVal));
        if (filter_expression.equals(""))
            filter_expression += "(" + path + " = :stringval" + i++ + ")";
        else
            filter_expression += " AND (" + path + " = :stringval" + i++ + ")";
    }
    scanRequest.withExpressionAttributeNames(expression_names).withExpressionAttributeValues(expression_values)
            .withFilterExpression(filter_expression);
    return dynamoDBClient.scan(scanRequest);

}

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