Add sample code for DDB enhanced client (#3354)

Author: zoewangg

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbAttribute.java

@@ -25,6 +25,26 @@
  * Used to explicitly designate a field or getter or setter to participate as an attribute in the mapped database
  * object with a custom name. A string value must be specified to specify a different name for the attribute than the
  * mapper would automatically infer using a naming strategy.
+ *
+ * <p>
+ * Example using {@link DynamoDbAttribute}:
+ * <pre>
+ * {@code
+ * @DynamoDbBean
+ * public class Bean {
+ *      private String internalKey;
+ *
+ *      @DynamoDbAttribute("renamedInternalKey")
+ *      public String getInternalKey() {
+ *          return this.internalKey;
+ *      }
+ *
+ *      public void setInternalKey(String internalKey) {
+ *          return this.internalKey = internalKey;}
+ *      }
+ * }
+ * }
+ * </pre>
  */
 @Target({ElementType.METHOD})
 @Retention(RetentionPolicy.RUNTIME)

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbBean.java

@@ -52,6 +52,33 @@
  * (converterProviders = {CustomAttributeConverter.class, DefaultAttributeConverterProvider.class});
  * }
  * </pre>
+ * <p>
+ * Example using {@link DynamoDbBean}:
+ * <pre>
+ * {@code
+ * @DynamoDbBean
+ * public class Customer {
+ *     private String id;
+ *     private Instant createdOn;
+ *
+ *     @DynamoDbPartitionKey
+ *     public String getId() {
+ *          return this.id;
+ *     }
+ *
+ *     public void setId(String id) {
+ *          this.name = id;
+ *     }
+ *
+ *     public Instant getCreatedOn() {
+ *          return this.createdOn;
+ *     }
+ *     public void setCreatedOn(Instant createdOn) {
+ *          this.createdOn = createdOn;
+ *      }
+ * }
+ * }
+ * </pre>
  */
 @Target({ElementType.TYPE})
 @Retention(RetentionPolicy.RUNTIME)

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbIgnore.java

@@ -23,6 +23,25 @@
 
 /**
  * Opts this attribute out of participating in the table schema. It will be completely ignored by the mapper.
+ * <p>
+ * Example using {@link DynamoDbAttribute}:
+ * <pre>
+ * {@code
+ * @DynamoDbBean
+ * public class Bean {
+ *      private String internalKey;
+ *
+ *      @DynamoDbIgnore
+ *      public String getInternalKey() {
+ *          return this.internalKey;
+ *      }
+ *
+ *      public void setInternalKey(String internalKey) {
+ *          return this.internalKey = internalKey;}
+ *      }
+ * }
+ * }
+ * </pre>
  */
 @Target({ElementType.METHOD})
 @Retention(RetentionPolicy.RUNTIME)

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbImmutable.java

@@ -52,6 +52,59 @@
  * (converterProviders = {CustomAttributeConverter.class, DefaultAttributeConverterProvider.class});
  * }
  * </pre>
+ *
+ * <p>
+ * Example using {@link DynamoDbImmutable}:
+ * <pre>
+ * {@code
+ * @DynamoDbImmutable(builder = Customer.Builder.class)
+ * public class Customer {
+ *     private final String accountId;
+ *     private final int subId;
+ *     private final String name;
+ *     private final Instant createdDate;
+ *
+ *     private Customer(Builder b) {
+ *         this.accountId = b.accountId;
+ *         this.subId = b.subId;
+ *         this.name = b.name;
+ *         this.createdDate = b.createdDate;
+ *     }
+ *
+ *     // This method will be automatically discovered and used by the TableSchema
+ *     public static Builder builder() { return new Builder(); }
+ *
+ *     @DynamoDbPartitionKey
+ *     public String accountId() { return this.accountId; }
+ *
+ *     @DynamoDbSortKey
+ *     public int subId() { return this.subId; }
+ *
+ *     @DynamoDbSecondaryPartitionKey(indexNames = "customers_by_name")
+ *     public String name() { return this.name; }
+ *
+ *     @DynamoDbSecondarySortKey(indexNames = {"customers_by_date", "customers_by_name"})
+ *     public Instant createdDate() { return this.createdDate; }
+ *
+ *     public static final class Builder {
+ *         private String accountId;
+ *         private int subId;
+ *         private String name;
+ *         private Instant createdDate;
+ *
+ *         private Builder() {}
+ *
+ *         public Builder accountId(String accountId) { this.accountId = accountId; return this; }
+ *         public Builder subId(int subId) { this.subId = subId; return this; }
+ *         public Builder name(String name) { this.name = name; return this; }
+ *         public Builder createdDate(Instant createdDate) { this.createdDate = createdDate; return this; }
+ *
+ *         // This method will be automatically discovered and used by the TableSchema
+ *         public Customer build() { return new Customer(this); }
+ *     }
+ * }
+ * }
+ * </pre>
  */
 @Target({ElementType.TYPE})
 @Retention(RetentionPolicy.RUNTIME)

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbPartitionKey.java

@@ -25,6 +25,34 @@
 /**
  * Denotes this attribute as being the primary partition key of the DynamoDb table. This attribute must map to a
  * DynamoDb scalar type (string, number or binary) to be valid. Every mapped table schema must have exactly one of these.
+ *
+ * <p>
+ * Example using {@link DynamoDbPartitionKey}:
+ * <pre>
+ * {@code
+ * @DynamoDbBean
+ * public class Customer {
+ *     private String id;
+ *     private Instant createdOn;
+ *
+ *     @DynamoDbPartitionKey
+ *     public String getId() {
+ *          return this.id;
+ *     }
+ *
+ *     public void setId(String id) {
+ *          this.name = id;
+ *     }
+ *
+ *     public Instant getCreatedOn() {
+ *          return this.createdOn;
+ *     }
+ *     public void setCreatedOn(Instant createdOn) {
+ *          this.createdOn = createdOn;
+ *      }
+ * }
+ * }
+ * </pre>
  */
 @SdkPublicApi
 @Target({ElementType.METHOD})

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/mapper/annotations/DynamoDbSortKey.java

@@ -25,6 +25,34 @@
 /**
  * Denotes this attribute as being the optional primary sort key of the DynamoDb table. This attribute must map to a
  * DynamoDb scalar type (string, number or binary) to be valid.
+ *
+ * Example using {@link DynamoDbSortKey}:
+ * <pre>
+ * {@code
+ *    @DynamoDbBean
+ *    public class Customer {
+ *        private String accountId;
+ *        private int subId;
+ *
+ *        @DynamoDbPartitionKey
+ *        public String getAccountId() {
+ *              return this.accountId;
+ *        }
+ *
+ *        public void setAccountId(String accountId) {
+ *              this.accountId = accountId;
+ *         }
+ *
+ *        @DynamoDbSortKey
+ *        public int getSubId() {
+ *              return this.subId;
+ *        }
+ *        public void setSubId(int subId) {
+ *              this.subId = subId;
+ *        }
+ *    }
+ * }
+ * </pre>
  */
 @SdkPublicApi
 @Target({ElementType.METHOD})