package com.aws.lhnng; import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClient; import software.amazon.awssdk.enhanced.dynamodb.DynamoDbTable; import software.amazon.awssdk.enhanced.dynamodb.Expression; import software.amazon.awssdk.enhanced.dynamodb.TableSchema; import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean; import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbPartitionKey; import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbSortKey; import software.amazon.awssdk.enhanced.dynamodb.model.PutItemEnhancedRequest; import software.amazon.awssdk.services.dynamodb.model.*; import java.util.HashMap; import java.util.Map; public class PutItemConditional { public static void main(String[] args){ try{ // Create Client DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.create(); // Map Table Using Bean DynamoDbTable table = enhancedClient.table("RetailDatabase", TableSchema.fromBean(Customer.class)); // Create Address HashMap address = new HashMap<>(); address.put("road", "456 Nowhere Lane"); address.put("city", "Langely"); address.put("state", "WS"); address.put("pcode", "98260"); address.put("country","USA"); // Update expression, update only if sk does not exist final Expression expression = Expression.builder() .expression("attribute_not_exists(sk)") .build(); Customer customer = new Customer.Builder("jim.bob@somewhere.com") .withSk("metadata") .withAddress(address) .withName("Jim Bob") .withFirstName("Jim") .withLastName("Bob") .withUsername("jbob") .build(); PutItemEnhancedRequest request = PutItemEnhancedRequest.builder(Customer.class) .item(customer) .conditionExpression(expression) .build(); // Add Item table.putItem(request); }catch (Exception e){ handleCommonErrors(e); } } @DynamoDbBean public static class Customer { private String pk; private String sk; private String name; private String firstName; private String lastName; private Map address; private String username; public Customer() { } // Partition Keys @DynamoDbPartitionKey public String getPk() { return pk; } public void setPk(String pk) { this.pk = pk; } @DynamoDbSortKey public String getSk() { return sk; } public void setSk(String sk) { this.sk = sk; } // Attributes public String getName() { return name; } public void setName(String name) { this.name = name; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public Map getAddress() { return address; } public void setAddress(Map address) { this.address = address; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } // Static Builder Class public static class Builder { private String pk; private String sk; private String name; private String firstName; private String lastName; private Map address; private String username; public Builder(String pk) { this.pk = pk; } public Builder withSk(String sk) { this.sk = sk; return this; } public Builder withName(String name) { this.name = name; return this; } public Builder withFirstName(String firstName) { this.firstName = firstName; return this; } public Builder withLastName(String lastName) { this.lastName = lastName; return this; } public Builder withAddress(Map address){ this.address = address; return this; } public Builder withUsername(String username) { this.username = username; return this; } public Customer build() { Customer cust = new Customer(); cust.pk = this.pk; cust.sk = this.sk; cust.name = this.name; cust.firstName = this.firstName; cust.lastName = this.lastName; cust.address = this.address; cust.username = this.username; return cust; } } } // Exception Helper Method private static void handleCommonErrors(Exception exception) { try { throw exception; } catch (InternalServerErrorException isee) { System.out.println("Internal Server Error, generally safe to retry with exponential back-off. Error: " + isee.getMessage()); } catch (RequestLimitExceededException rlee) { System.out.println("Throughput exceeds the current throughput limit for your account, increase account level throughput before " + "retrying. Error: " + rlee.getMessage()); } catch (ProvisionedThroughputExceededException ptee) { System.out.println("Request rate is too high. If you're using a custom retry strategy make sure to retry with exponential back-off. " + "Otherwise consider reducing frequency of requests or increasing provisioned capacity for your table or secondary index. Error: " + ptee.getMessage()); } catch (ResourceNotFoundException rnfe) { System.out.println("One of the tables was not found, verify table exists before retrying. Error: " + rnfe.getMessage()); } catch (ConditionalCheckFailedException ccfe){ System.out.println("Condition evaluated to false: " + ccfe.getMessage()); } catch (Exception e) { System.out.println("An exception occurred, investigate and configure retry strategy. Error: " + e.getMessage()); } } }