Which interface provides the method gethandle()

By default, the template in the group with the same name as the method will be used. The Vavr Plugin offers deep integration of Jdbi with the Vavr functional library:. Given that for the wrapped type T a Mapper is registered.

Return Vavr collection types from queries. For all interface types a sensible default implementation will be used e. Tuple projections for Jdbi! Vavr offers Tuples up to a maximum arity of 8. If you select more columns than the arity of the projection the columns up to that index will be used. The plugin pulls a supported version of Vavr and is ready to be used. As with other plugins: install via Jdbi instance or use auto install.

Note that in the case of these types, the nested value must be 'present' otherwise a null value is used e. Left or Validation. This works for all the collection types supported. For the nested value row and column mappers already installed in Jdbi will be used. Therefore the following would work and can make sense if the column is nullable:. In the next example we will key users by their name, which is not necessarily unique. If you want to mix complex types and simple ones we also got you covered.

Using the TupleMappers class you can configure your projections. In fact, you have to - read below! The configuration of the columns is 1-based, since they reflect the tuples' values which you would query by e. Tuples are always mapped fully column-wise or fully via row mappers. If you want to mix row-mapped types and single-column mappings the TupleMappers must be configured properly i.

Just do field injection on a simple custom config type:. This is because JDBC drivers will not bind arguments inside string literals. Now, search can be properly bound as a parameter to the statement, and it all works as desired. Jdbi can be combined with connection pools and high-availability features in your database driver.

Each Jdbi may be backed by a pool of any number of hosts, but the connections should all be alike. Exactly which parameters must stay the same and which may vary depends on your database and driver. If you want to have two separate pools, for example a read-only set that connects to read replicas and a smaller pool of writers that go only to a single host, you currently should have separate Jdbi instances each pointed at a separate DataSource.

By default, the Java compiler does not write parameter names of constructors and methods to class files. At runtime, reflectively asking for parameter names gives values like "arg0", "arg1", etc. Under "Classfile Generation," check the option "Store information about method parameters usable via reflection.

GenericType represents a generic type signature that can be passed around in a type-safe way. The GenericType. Type object used to represent generics in Java. GenericTypes provides methods for working with Java generic types signatures. All methods in GenericTypes operate in terms of java. The getErasedType Type method accepts a Type and returns the raw Class for that type, with any generic parameters erased:. The resolveType Type, Type method takes a generic type, and a context type in which to resolve it.

This scenario of resolving the first type parameter of some generic supertype is so common that we made a separate method for it:. Note that this method will return Optional. The NamedArgumentFinder interface, as its name suggests, finds arguments by name from some source.

Typically a single NamedArgumentFinder instance will provide arguments for several different names. In cases where neither bindBean , bindFields , bindMethods , nor bindMap are a good fit, you can implement your own NamedArgumentFinder and bind that, instead of extracting and binding each argument individually. Configuration is managed by the ConfigRegistry class. Each Jdbi object that represents a distinct database context for example, Jdbi itself, a Handle instance, or an attached SqlObject class gets its own configuration registry.

When a new configurable context is created, it inherits a copy of its parent configuration at the time of creation - further modifications to the original will not affect already created configuration contexts. Configuration context copies happen when producing a Handle from Jdbi, when opening a SqlStatement from the Handle, and when attaching or creating an on-demand extension such as SqlObject.

The configuration itself is stored in various implementations of the JdbiConfig interface. Each implementation must adhere to the contract of the interface; in particular it must have a public no-argument constructor that provides useful defaults and a createCopy method that is invoked when a configuration registry is cloned. Generally, configuration should be set on a context before that context is used, and not changed later. Some configuration classes may be thread safe but most are not.

Override setConfig ConfigRegistry if your config class wants to be able to use other config classes in the registry. JdbiPlugin can be used to bundle bulk configuration. Plugins may be installed explicitly via Jdbi. JdbiPlugin containing the fully qualified class name of your plugin. Modules that provide no e. The StatementContext class is a carrier for various state related to the creation and execution of statements that is not appropriate to hold on the Query or other particular statement class itself.

The StatementContext itself is not intended to be extended and generally extensions should not need to mutate the context.

Please read the JavaDoc for more information on advanced usage. SQL Object is designed to be extended with user-defined annotations. In fact, most of the annotations provided in Jdbi are wired up with the approach outlined below. Statement Customizing Annotations - configures the underlying SqlStatement of a method prior to execution. These can only be used in tandem with annotations like SqlQuery , SqlUpdate , etc, and do not work on default methods.

Configuration Annotations - modifies configuration in the ConfigRegistry within the scope of a SQL object or one of its methods. Method Decorating Annotations - decorates a method invocation with some additional behavior, e. Once you know which type of annotation you want, proceed to the appropriate section below and follow the guide to set it up. Typically these annotations correlate to an API method in core. Bind corresponds to SqlStatement. Customizing annotations are applied only after the SqlStatement has been created.

You can create your own SQL statement customizing annotations and attach runtime behavior to them. When used on parameters, annotations may use the argument passed to the method while processing the annotation. Next, we write an implementation of the SqlStatementCustomizerFactory class, to process the annotation and apply the customization to the statement. The SqlStatementCustomizerFactory produces two different types of "statement customizer" command objects: SqlStatementCustomizer for annotations on types or methods , and SqlStatementParameterCustomizer for annotations on method parameters.

Configuration annotations are used to apply some change to the ConfigRegistry associated with a SQL object or method. Typically these annotations correlate to a method of Configurable Jdbi , Handle , and SqlStatement all implement this interface.

For example, RegisterColumnMapper correlates to Configurable. Write an implementation of Configurer which performs the configuration associated with your annotation. With the above steps completed, Jdbi will invoke your configurer whenever it encounters the associated annotation. The RegisterColumnMapper annotation has an attribute to specify the class of the column mapper to register.

Wherever the annotation is used, we want Jdbi to create an instance of that mapper type, and register it with the config registry. Next, we write an implementation of the Configurer class, to process the annotation and apply the configuration:. For configuration annotations with only one target, e. KeyColumn and ValueColumn may only be applied to methods , you need only implement the Configurer method appropriate for the annotation target. Method decorating annotations are used to enhance a SQL Object method with additional or substitute behavior.

Internally, SQL Object represents the behavior of each method with an instance of the Handler interface. Every time you call a method on a SQL Object instance, the method is executed by executing the handler for the given method. A decorator could even perform some action instead of calling the original, e. Next we write an implementation of the HandlerDecorator interface, to process the annotation and apply the decoration:. This tells Jdbi that TransactionDecorator implements the behavior of the Transaction annotation.

If a SQL object method has two or more decorating annotations applied, and the order of decorations is important, use the DecoratorOrder annotation. If no order is declared, type decorators apply first, then method decorators, but the order is not further specified.

For example, suppose a method were annotated both with Cached and Transaction just go with it.. We would probably want the Cached annotation to go first, so that transactions are not created unnecessarily when the cache already contains the entry.

Any custom template engine can be used. Out of the box, Jdbi is configured to use ColonPrefixSqlParser , which recognizes colon-prefixed named parameters, e. Jdbi also provides HashPrefixSqlParser , which recognizes hash-prefixed parameters, e. For you fearless adventurers who have read the Dragon book , any custom SQL parser can be used. The SqlLogger interface is called before and after executing each statement, and given the current StatementContext , to log any relevant information desired: mainly the query in various compilation stages, attributes and bindings, and important timestamps.

A ResultProducer takes a lazily supplied PreparedStatement and produces a result. The most common producer path, execute , retrieves the ResultSet over the query results and then uses a ResultSetScanner or higher level mapper to produce results. If you acquire the lazy statement, you are responsible for ensuring that the context is closed eventually to release database resources.

Jdbi includes an experimental SqlObject code generator. If you include the jdbi3-generator artifact as an annotation processor and annotate your SqlObject definitions with GenerateSqlObject , the generator will produce an implementing class and avoid using Proxy instances.

This may be useful for graal-native compilation. Jdbi tries to be defensive and fail eagerly when you hold it wrong. Use the -parameters compiler flag to avoid all those Bind "foo" String foo redundant qualifiers in SQL Object method parameters.

See Compiling with Parameter Names. Use a profiler! The true root cause of performance problems can often be a surprise. Measure first, then tune for performance. And then measure again to be sure it made a difference. Embedded Postgres makes testing against a real database quick and easy. Please check out the project page for more information. If you have a question, we have a Google Group mailing list. Users sometimes hang out on IRC in jdbi on Freenode. Call Handle. AbstractArgumentFactory is a generic implementation of ArgumentFactory for factories that handle a single argument type.

Argument and mapper factories now operate in terms of java. Type instead of java. This allows Jdbi to handle arguments and mappers for generic types. Argument and mapper factories now have a single build method that returns an Optional , instead of separate accepts and build methods.

The row index parameter was also removed from RowMapper --the current row number can be retrieved directly from the ResultSet. Call Query. Just rollback the handle now. CallbackFailedException class removed. The functional interfaces like HandleConsumer , HandleCallback , TransactionCallback , etc can now throw any exception type. Methods like Jdbi. StatementLocator interface removed from core.

All core statements expect to receive the actual SQL string now. Custom SqlParser implementations must now provide a way to transform raw parameter names to names that will be properly parsed out as named params.

SQL Object support is not installed by default. It must be added as a separate dependency, and the plugin installed into the Jdbi object:. Method return types must likewise be public.

Proxy , which only supports interfaces. Bind annotations on SQL Object method parameters can be made optional, by compiling your code with the -parameters compiler flag enabled. On-demand objects strictly close the handle after each method call, and no longer "hold the door open" for you to finish consuming the interable as they did in v2.

This forecloses a major source of connection leaks. BindAnnotation meta-annotation removed. Use SqlStatementCustomizingAnnotation instead. The annotation may be used for method return types, or on SqlBatch parameters. Jdbi 3 Developer Guide version 3. Introduction to Jdbi Jdbi provides convenient, idiomatic access to relational data in Java. Not upgrading yet? The v2 documentation is still available. Instead, Jdbi provides straightforward mapping between SQL and simple tabular data structures.

Already using Jdbi v2? See Upgrading from v2 to v3. Getting Started Jdbi is easy to include in your Java project - with an Apache 2. Jdbi provides several other modules, which enhance the core API with additional features. Java Compatibility Jdbi runs on all Java versions 8 or later. Java 8 support is considered deprecated and will be maintained best-effort for now, but will be going away soon!

In order to run on 8, you might need to dependency-manage your caffeine version back to 2. Most Jdbi users use this.

Beta and org. Our org. Core API 3. Jdbi The Jdbi class is the main entry point into the library. There are a few ways to create a Jdbi instance. If you have a DataSource object, you can use that directly:.

Jdbi instances are thread-safe and do not own any database resources. Handle Handles represent an active database connection. Because Handle holds an open connection, care must be taken to ensure that each handle is closed when you are done with it.

Failure to close Handles will eventually overwhelm your database with open connections, or drain your connection pool. There are a few ways to obtain a Handle instance at runtime. You may notice the "consumer" vs "callback" naming pattern in a few places in Jdbi. Callbacks return a value, and are coupled to with- methods. Consumers do not return a value, and are coupled to use- methods.

When using jdbi. Failing to release the handle will leak connections. We recommend using withHandle or useHandle over open whenever possible. See Templating and TemplateEngine for more information. This :foo syntax is default behavior that can be changed; see the ColonPrefixSqlParser class. Jdbi alternatively provides support for foo syntax out-of-the-box, and you can create your own as well.

Mixing named and positional arguments is not allowed, as it would become confusing very quickly. Primitives: boolean , byte , short , int , long , char , float , and double java. You can also configure Jdbi to support additional argument types.

More on that later. You can bind multiple arguments at once from the entries of a Map :. Using bindList requires writing your SQL with an attribute, not a binding, despite the fact that your values are bound. The attribute is a placeholder that will be safely rendered to a comma-separated list of binding placeholders.

The authors recommend checking out Immutables support for an advanced way to easily bind and map value types. Custom Arguments Occasionally your data model will use data types not natively supported by Jdbi see Supported Argument Types.

Core JDBC features are generally well supported by all database vendors. However, more advanced usages like array support or geometry types tend to quickly become vendor-specific. Argument The Argument interface wraps a single value into a binding. ArgumentFactory The ArgumentFactory interface provides Argument instances for any data type it knows about. Jdbi needs this in order to bind UUID values of null. See PreparedStatement. Prepared Arguments Traditional argument factories decide to bind based on both the type and actual value of the binding.

Arguments Registry When you register an ArgumentFactory , the registration is stored in an Arguments instance held by Jdbi. Occasionally, two or more argument factories will support arguments of the same data type.

When this happens, the last-registered factory wins. Preparable argument factories always take precedence over base argument factories. This means that you can override the way any data type is bound, including the data types supported out of the box. Mappers Jdbi makes use of mappers to convert result data into Java objects. Row Mappers , which map a full row of result set data. Column Mappers , which map a single column of a result set row. There are three different types being used in the above example.

Query , returned by Handle. The ResultBearing. Finally, ResultBearing. This RowMapper is equivalent to the lambda mapper above but more explicit. RowMappers registry Row mappers can be registered for particular types. Implementing a factory might be preferable to a regular row mapper if:.

You want to bundle multiple mappers into a single class. Next, we extract the L and R generic parameters from the mapped type:. If it knows the mapped type but is missing some configuration to make it work e. Row mapper factories may be registered similar to regular row mappers:. Whenever a column mapper is used to map rows, only the first column of each row is mapped.

This ColumnMapper is equivalent to the lambda mapper above, but more explicit. ColumnMappers registry Column mappers may be registered for specific types. Out of the box, column mappers are registered for the following types:. The binding and mapping method for enum values can be controlled via the Enums config, as well as the EnumByName and EnumByOrdinal annotations. Implementing a factory might be preferable to a regular column mapper if:.

The mapper class is generic, and could apply to multiple mapped types. Next, extract the T generic parameter from the mapped type:. Finally, we construct the column mapper for optionals, and return it:. Column mapper factories may be registered similar to regular column mappers:. Immutables Mapping Immutables value objects may be mapped, see the Immutables section for details.

Freebuilder Mapping Freebuilder value objects may be mapped, see the Freebuilder section for details. Reflection Mappers Jdbi provides a few reflection-based mappers out of the box.

To instruct Jdbi to ignore an otherwise mappable method, annotate it as Unmappable. ConstructorMapper Jdbi provides a simple constructor mapper which uses reflection to assign columns to constructor parameters by name. Register a constructor mapper for your mapped class using the factory method:.

First, use the constructor annotated with JdbiConstructor , if any. Next, use the constructor annotated with ConstructorProperties , if any. When binding object properties e. Nested constructor-injected types can be mapped using the Nested annotation:. Any Nullable annotation from any package may be used.

Nullable is a good choice. BeanMapper We also provide basic support for mapping beans:. Register a bean mapper for your mapped class, using the factory method:. Alternatively, call mapToBean instead of registering a bean mapper:. The ColumnName annotation can be placed on either the getter or setter method. Nested Java Bean types can be mapped using the Nested annotation:.

Nested properties are left unmodified i. FieldMapper FieldMapper uses reflection to map database columns directly to object fields including private fields. Register a field mapper for your mapped class, using the factory method:. Nested field-mapped types can be mapped using the Nested annotation:.

Nested fields are left unmodified i. A mapper must be registered for both the key and value type. Join rows can be gathered into a map result by specifying the generic map signature:. A unique index e. Set both the key and value column names to gather a two-column query into a map result:. Then, simply ask for a Multimap instead of a Map :. Obtain a mapper for that element type from the mapping registry. Finally, return map elementMapper. If the lookup for the collector factory, element type, or element mapper fails, an exception is thrown.

Resolving Types By using the TypeResolvingCodecFactory from the guava module, it is possible to use codecs that are registered for subclasses or interface types for concrete classes. Templating Binding query parameters, as described above, is excellent for sending a static set of parameters to the database engine. Query templating is a common attack vector! Use a TemplateEngine to perform crude String manipulations on a query.

Query parameters should be handled by Arguments. TemplateEngines and SqlParsers operate sequentially: the initial String will be rendered by the TemplateEngine using attributes, then parsed by the SqlParser with Argument bindings.

Also see the section about TemplateEngine. ClasspathSqlLocator You may find it helpful to store your SQL templates in individual files on the classpath, rather than in string inside Java code.

Plugins like PostgresPlugin and H2DatabasePlugin automatically register the most common array element types for their respective databases. Binding custom array types You can also provide your own implementation of SqlArrayType that converts a custom Java element type to a type supported by the JDBC driver:.

Like the Arguments Registry , if there are multiple SqlArrayType s registered for the same data type, the last registered wins. Array columns can be mapped to any container type registered with the JdbiCollectors registry.

Results After executing a database query, you need to interpret the results. The mapper is selected based on the declared result type of your query. ResultBearing The ResultBearing interface represents a result set of a database operation, which has not been mapped to any particular result type.

Query implements ResultBearing Update. ResultIterable ResultIterable represents a result set which has been mapped to a specific type, e. Use try-with-resources to ensure database resources get cleaned up. Find a Single Result ResultIterable. Reduction reduce provides a simplified Stream reduce. The return value ends up being the final result of statement execution.

Joins Joining multiple tables together is a very common database task. Here we present a couple of strategies for retrieving results from more complicated rows. LinkedHashMap is a good accumulator when selecting multiple master records, since it has fast storage and lookup while preserving insertion order which helps honor ORDER BY clauses. If ordering is unimportant, a HashMap would also suffice.

So we call Map. The map is a LinkedHashMap , so the result stream will yield the result objects in the same order they were inserted. The same map is reused on every row. In this example, we collect the elements into a list, but we could call any Stream method here. While this approach is easy to read and write, it can be inefficient for certain patterns of data. Consider performance requirements when deciding whether to use high level mapping or more direct low level access with handwritten mappers.

Updates may return Generated Keys instead of a result count. Batches A Batch sends many commands to the server in bulk. After opening the batch, repeated add statements, and invoke add. Prepared Batches A PreparedBatch sends one statement to the server with many argument sets.

Test with your database configuration, but often extremely large data sets should be divided and committed in pieces - or risk bringing your database to its knees. BatchUpdateException: Batch entry 1 insert into something id, name values 0, '' was aborted. Call getNextException to see the cause.

BatchUpdateException: Batch entry 1 insert into something id, name values 0, 'Keith' was aborted. Suppressed: org. Stored Procedure Calls A Call invokes a database stored procedure. This tells JDBC what data type to expect for each out parameter. Multiple output parameters may be registered, depending on the output of the stored procedure itself. This cannot be expanded through e.

Scripts A Script parses a String into semicolon terminated statements. Transactions jdbi provides full support for JDBC transactions. Both optionally allow you to specify the transaction isolation level. Serializable Transactions For more advanced queries, sometimes serializable transactions are required.

Configuration Jdbi aims to be useful out of the box with minimal configuration. Generally, you should finalize all configuration changes before interacting with the database. See JdbiConfig for more advanced implementation details. Qualified Types Sometimes the same Java object can correspond to multiple data types in a database. Jdbi chooses factories to handle values by exactly matching their qualifiers.

Qualifiers are implemented as Annotations. Qualifiers being annotations does not mean they inherently activate their function when placed in source classes. Each feature decides its own rules regarding their use. Arguments can only be qualified for binding via bindByType calls, not regular bind or update. Also, arrays cannot be qualified. BindMethods and bindMethods respect qualifiers on methods. SqlUpdate Use the SqlUpdate annotation for operations that modify data i.

We recommend using a schema migration tool such as Flyway or Liquibase to maintain your database schemas. By default, a SqlUpdate method may return a handful of types:. Databases vary in support for generated keys. Some support only one generated key column per statement, and some such as Postgres can return the entire row.

Because the database and index are not updated at the same time, it is possible for a deleted entity to still be represented in the search index. Do not assume that this handle will always refer to a live object. Specified by: getHandle in interface BaseSearchResult Returns: the handle that can be used to look up the underlying database object. See Also: AnyTypeDao. This method will return null if there is no content for the field or the field does not exist.

FieldName is case sensitive. If more than one field name is provided, it will attempt to retrieve a value for each field in order, returning as soon as a non-null value is encountered.

Parameters: fieldNames - field name s to retrieve a value for Returns: the first non-null value associated with the ordered list of field names passed in getUserResult protected ConfluenceUser getUserResult String fieldName Attempts to resolve the contents of the given field as a ConfluenceUser. The method first attempts to resolve the user using the field value as a UserKey. If that fails, it tries to resolve the user using the field value as a username.

If that fails, it returns null. This is necessary because the same DocumentFieldName. Since: 5. All rights reserved. Skip navigation links. Object com. The ArchiveManager seems to be working pretty well too. Update : I've totally reimplemented persistent identifiers in DSpace as well see PersistentIdentifiers. Update : Everything apart from the code in org.

There are interfaces for CRUD and link operations in org. If nothing else, it would make porting to alternative database platforms far easier; all we would need to do is provide alternative implementations for the DAO interfaces that worked for a given database.

To this end, I have broken up some of the core classes in org. As part of the same effort, I have done some work on making the Context less data-layer dependent by having it hold a org. GlobalDAO rather than a java.

Connection , etc. I've also introduced a proxy for the Item that is a bit smarter about when it retrieves content from the data layer, and an ArchiveManager class that takes care of some core "archive operations" so that other core classes don't need to. Without further ado, here is how I have refactored org.

Item to use DAOs. A few important things to note:. For examples of both of these principles, see the implementation of getItems below. It is a fairly straightforward wrapper for the current Item. Note that it might be preferable to have a more generic implementation of the ItemDAO interface that supports both PostgreSQL and Oracle, but given that one motivation for adopting DAOs is to remove db-specificities from the code making it easier to port, I thought it was sensible to start with just PostgreSQL.

Eventually, it ought to be possible to drop in ItemDAOHibernate etc implementations that make db portability far easier. Basic implementation of the Item object.