Spring boot jdbc exception handling

Spring boot jdbc exception handling. Exception handling is one of the core concepts which is really necessary when we build an application using spring boot. While a root exception match is preferred to a cause, this is defined among the methods of a given controller or @ControllerAdvice class. this is the code that I made in spring boot. However, our application was not very robust. This annotation is used to define a method that can handle a specific exception type. Basics of Web 13. Spring and Spring Boot 14. servlet. Yes, the exceptions should be handled, but in Spring design, on higher level then the each DAO method. Increase the max poolside to start with. So in REST API development, it carries a bigger role. Most Spring Boot applications need very little Spring configuration. Resource Not Present Jul 9, 2023 · 2. core. exceptions. It is not possible to throw those exceptions in this fashion. The table shows what actions Spring will take care of and which actions are the responsibility of you, the application developer. It is a combination of Spring Framework and Embedded Servers. Using these Spring Boot server properties in our application Mar 9, 2023 · The simplest way to handle exceptions in Spring Boot is by using the @ExceptionHandler annotation. 2 support and into 4. If you want to specifically catch SQLRecoverableException, then you can do something like, @Override. Mar 17, 2024 · 5. So in this tutorial, I’m going to explain how we can configure exception handling in spring boot REST API. Aug 12, 2015 · What you need to do is catch the exception EmptyResultDataAccessException and then return null back. The proxy allows the framework to inject transactional logic before and after the running method, mainly for starting and committing the transaction. We can autowire these classes if we want to use it. The easiest and fastest way to create our sample project is by using Spring Boot. Jul 11, 2022 · Based on configuration & stacktrace, it says: Caused by: java. We will cover key concepts and provide detailed context on the topic. Jul 3, 2022 · We will use the same example to discuss about Exception Handling. out. Exception handling is an important aspect of any application, and it is especially crucial in a Spring Boot application. 4. Persistence Exception Translation is the process of converting low level persistence exceptions into high level Spring exceptions. I downloaded the ojdbc14 jar from Oracle and ran the command: My application. Author: Ramesh Fadatare. Also there's Flyway, configured apart. when I try submit the request from the postman it is returning org. Spring Boot provides good default implementation for exception handling for RESTful Services. properties is done like: When I try to start the application, I see the exception: Mar 3, 2019 · Exception Handling is one of the most important aspects of a production-level Spring Boot Microservice. Nov 22, 2017 · In the SQL Server 2005 JDBC driver, Microsoft changed this to com. x. Aug 3, 2022 · Spring JdbcTemplate. sqlserver</groupId>. By doing so, we can send proper response to the client. INTERNAL_SERVER_ERROR; I am unsure of what else to do. Java provides five keywords that are used to handle the exception. When utilizing Spring Data JPA in conjunction with an ORM technology like Hibernate, the persistence layer becomes nicely . Concurrency 7. 1 Jan 04 02:24:27 danef-dictionary-api Data access using JDBC. } catch (DataAccessException e) {. These exceptions mostly extend from HibernateException. The best way to handle those errors is to look at logs, push them to Mar 18, 2022 · spring: datasource: url: jdbc:h2:mem:exception username: sa password: password In a Spring Boot application, handling exceptions is a crucial aspect of ensuring the reliability and robustness Dec 8, 2016 · I have lots of scheduled tasks in my Spring Boot (ver 1. Here Spring Boot JDBC provides starter and libraries for connecting an application with JDBC. @ExceptionHandler (ConstraintViolationException::class) fun handleConstraintViolation (ex: ConstraintViolationException, request: WebRequest): ResponseEntity {} this kotlin snippet u can convert to java easily –. But you should throw a specific exception of your application such as : try. myproject") to my SpringBootApplication Jan 8, 2024 · An exception is an abnormal condition that arises in a code sequence at runtime or at compile time. Feb 24, 2020 · To use JDBC with Spring Boot, we need to specify the spring-boot-starter-jdbc dependency. Jan 4, 2020 · com. throw new MyApplicationException("A problem occurred while retrieving my data", e); Mar 9, 2024 · In JDBC, we may get exceptions when we execute or create the query. It also explains how to integrate with other Spring modules, such as Spring Data and Spring Boot. <groupId>com. Many conditions can cause exceptions to be thrown while using Hibernate. To create it, we need to understand Spring @ControllerAdvice and @ExceptionHandler annotations. Apr 4, 2023 · 4. properties file under the src/main/resources directory with the following content: Spring JDBC - Overview. This approach does not work for tasks that are defined with @Scheduled annotation because of threading: Aug 3, 2022 · Sometime back I wrote a post about Exception Handling in Java but when it comes to web application, we need more than normal exception handling in java. Let’s quickly look at the default Exception Handling features provided by Spring Boot. Explore Spring Boot for rapid application development. The source code examples of this guide are well-tested with our local development environment and you can use these code examples as bug-free. Managing errors in a project is one of the most important aspects since it is crucial Nov 22, 2021 · This time around, we appended the -v flag to the curl command and we can see from the verbose response that the HTTP code returned is indeed 500 — the same as the value of code in the returned Dec 23, 2012 · Spring Batch. Spring Boot provides a comprehensive framework for handling exceptions, including both built-in Mar 8, 2024 · Handling Exceptions in a Spring Boot REST API with JDBC Template: Authentication Manager Implementation. You should also implement handleOtherException() to handle exceptions that occur outside the scope of record processing (e. <artifactId>ojdbc14</artifactId>. Before proceeding with exception handling, let us understand the following annotations. The value-add provided by the Spring Framework JDBC abstraction is perhaps best shown by the sequence of actions outlined in the table below. UnknownHostException: localhost: This means in your datasource string, you have defined extra : Feb 28, 2019 · 1. HibernateJpaDialect to get an idea). In your webapplication, You need to do two things to achieve exception translation. When I add @ComponentScan(basePackages="com. Here we will see how we can use both of this to create the custom exception handler in spring-boot: 1. Mar 31, 2023 · In Spring Boot, you can handle exceptions by using the @ExceptionHandler annotation. Popular Tutorials Spring Tutorial Spring MVC Web Tutorial Spring Boot Tutorial Spring Security Tutorial Spring AOP Tutorial Spring JDBC Tutorial Spring Oct 28, 2016 · Then in your code just treat the SQLException as you want. 0. @ExceptionHandler. By the use of it, we can annotate a method with this, and it will be responsible for handling the exception if it occurs at this controller only. Handle exception in a Spring REST controller is slightly different. Configure Database Connection Properties. Add a proper datasource. Oct 8, 2020 · 1. Spring Boot JDBC is used to connect the Spring Boot application with JDBC by providing libraries and starter dependencies. Other Spring Boot Tutorials: Spring Boot automatic restart using Spring Boot DevTools; Spring Boot Form Handling Tutorial with Spring Form Tags and JSP; How to create a Spring Boot Web Application (Spring MVC with JSP/ThymeLeaf) Spring Boot - Spring Data JPA - MySQL Example Aug 9, 2020 · When you quote the names, they become case-sensitive, e. CONFLICT, reason="Data integrity violation") // 409. @ControllerAdvice Annotation. (Consult the documentation for your driver for the correct value. 2. 0. springframework. Your code should look like this. 2) application and would like to catch all exceptions from them using one handler like is possible for normal controllers with @ExceptionHandler annotation. Creating a Route. jar. customer_id and "customer_id" are not the same name. Check out the complete Java tutorial at Java Tutorial May 4, 2018 · I have a Spring Boot + JPA + Spring batch (+Spring Integration) project. In this tutorial, we’ll take a look at two approaches we can use for exception handling inside our Camel application. In this article, we will discuss how to handle exceptions in a Spring Boot REST API using the JDBC Template, with a focus on the implementation of the Authentication Manager. oracle</groupId>. Dec 9, 2019 · Stack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand Mar 26, 2022 · In case you want to handle more than one exception, you can specify an array of exception classes like this: @ExceptionHandler ( {Exception1. Create the application. transaction. net. It extends the Exception class which means that we can Apr 5, 2018 · For anyone coming across this answer, be cautious of the suggestion at the bottom of the answer in envs with multiple instances . Jul 5, 2022 · Exception Handling in Spring Boot helps to deal with errors and exceptions present in APIs so as to deliver a robust enterprise application. To navigate this chain of causes, recursively call the method SQLException. 7. spring-boot:jdbc re-connection after db outage. If you need it to throw, you can call flush() right after the line. Spring boot is developed by Pivotal Team, and it provides a faster way to set up and an easier, configure, and run both simple and web-based applications. 5. cj. Spring REST Global Exception Handler Examples. jpa. That is because H2 handles case-insensitivity by uppercasing unquoted names, so customer_id, Customer_Id, CUSTOMER_ID, and "CUSTOMER_ID" are all the same 1, but "customer_id" and "Customer_Id" are two entirely separate names. 1. x and 5. Let’s do the initial setup to explore each approach in more depth. The "try" keyword is used to specify a block where we should place an exception code. The term thrown means that current program execution stops, and the control is redirected to the nearest applicable catch clause. Hibernate About the Author Mandar Jog is a passionate Java trainer and has been conducting training for the last 15+ years. Exception handling allows you to handle exceptional conditions such as program-defined errors in a controlled fashion. I would also decrease the connection timeout (you don't want to wait 50seconds before you get an error). Exception Handling II. Jun 3, 2022 · By now, you should have a pretty good overview of how transaction management works with the Spring framework and how it also applies to other Spring libraries like Spring Boot or Spring WebMVC. For demonstration purposes, we’ll be using an in-memory H2 database. Last but not least, an @ExceptionHandler method Create a CustomExceptionHandler. If I'm not mistaken, which I very well could be, if your consuming service runs multiple instances (E. It performs the basic tasks of the core JDBC workflow (such as statement creation and execution), leaving application code to provide Spring Boot helps you to create stand-alone, production-grade Spring-based applications that you can run. ( and it will print "I am in catch"). Jul 8, 2016 · try {. Sep 2, 2018 · Spring boot exception handling rest service (CRUD) operations. Mar 14, 2018 · And I added the JDBC dependency in my pom. Transactions and Proxies. {. TransactionSystemException with HttpStatus code : 500 if invalid it throwing the javax. controller under the src folder in the created project. Any web application requires good design for exception handling because we don’t want to serve container generated page when any unhandled exception is thrown by our application. Chapter 11. When an exception occurs in the application, Spring Boot will look for a matching @ExceptionHandler method and execute it. However, I have learned the hard way not to rely on that as conditional logic for anything. Note that this is not necessarily a purely relational concept; unique primary keys are required by most database types. Apparently you need a DataSource as you configure something that requires it. Nov 22, 2018 · 1. May 12, 2023 · We will build a Spring Boot Rest API using Spring Data Jdbc with MySQL Database for a Tutorial application that: Each Tutorial has id, title, description, published status. sql package. Mar 17, 2023 · In Spring Boot, exception handling is a crucial part of building robust and reliable applications. Nov 8, 2017 · DB exceptions should always be fatal, that's why they are runtime. It makes the code extremely cumbersome and difficult to read. Learn data access in Spring with JDBC and Spring Data JPA. As I said, I cannot catch the exception directly because it is happening within the Spring code itself. xml file of your Spring Boot project: <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime Exception thrown when an attempt to insert or update data results in violation of a primary key or unique constraint. JdbcTemplate' that could not be found. valueOf(statusCode. sqlserver. This abnormal condition arises when a program violates the semantic constraints of the Java programming language. For this, we make a Global Exception Handler that handles all the exceptions in our application. There are various demands, and various places where you handle Data Access using JDBC. 9. Sep 22, 2018 · As kkflf said, the exception won't normally throw until the txn commits. – May 11, 2024 · Get started with Spring Boot and with core Spring, through the Learn Spring course: >> CHECK OUT THE COURSE. It means we can't use try block alone. Jan 25, 2024 · For this, Camel provides a couple of strategies for handling exceptions. ConstraintViolationException in the server. However, Spring JDBC Framework takes care of all the low-level details starting from opening the connection, preparing and executing the SQL statement Mar 11, 2022 · Spring MVC provides exception handling for your web application to make sure you are sending your own exception page instead of the server-generated exception to the user. A SQLException instance might have a causal relationship, which consists of one or more Throwable objects that caused the SQLException instance to be thrown. Not inside that transactional method. And DataAccessException is already a RuntimeException so that no need to throw a Runtime exception. This means a cause match on a higher-priority @ControllerAdvice bean is preferred to any match (for example, root) on a lower-priority @ControllerAdvice bean. You can then generate a custom exception to be catched by higher code to present to the end user. JdbcTemplate' in your configuration. Apis also support custom finder methods such as find by published status or by title. First, configure org. class, Exception3. b(); @Transactional. answered Feb 28, 2019 at 2:48. Can any one share the best solution to handle these exceptions? Jan 8, 2024 · 1. Spring-jdbc 5. You want to isolate the web-specific behaviors from the service layer, and from the data layer, and I think the best way to do that is to throw a new, checked, domain-specific Exception that matches the meaning of each case you want to handle differently in the Controller. These exceptions are direct subclasses of the Exception class 19. Spring can wrap exceptions from your O/R mapping tool of choice, converting them from proprietary (potentially checked) exceptions to a common runtime Apr 28, 2024 · In Java and Spring Boot, exceptions are divided into three main categories: Checked Exceptions: Checked at compile-time, these exceptions require explicit handling either through a try-catch block In this tutorial, you will learn how to build CRUD (Create, Read, Update, Delete) RESTFul APIs using Spring Boot, Microsoft SQL Server, JPA/Hibernate, and Maven. commons-logging-1. You can do Jan 9, 2024 · Spring Boot – JDBC. How to make Spring Boot application resistant against Oct 16, 2023 · Global exception handler is a common exception handler for more than one Spring controllers. 1. 3. Functional Programming 11. Mar 26, 2022 · You can also catch multiple exceptions in a single hander, as shown below: @ExceptionHandler ( {Exception1. class}) 3. Mar 29, 2023 · 20 connections for 500 users is probably to low. May 17, 2024 · 2. The JDBC abstraction framework provided by Spring consists of four different packages core, datasource , object, and support. datasource". As per SQLRecoverableException, its subtype of Exception so in case of SQLRecoverableException, control will always goes to Exception block which you have defined. File Handling 6. In fact the design where in every method there is SQLException handling is unclean copy-paste design, and when you change something, you must apply the change in every place. Data access with JDBC. CommunicationsException: Communications link failure Jan 04 02:24:27 danef-dictionary-api app/web. 0 libraries and other libraries into the folder WebRoot/WEB-INF/lib . All we’ll need to get started is the camel-spring-boot-starter added to our pom. 2. You can use Spring Boot to create Java JDBC - Exceptions Handling. In this tutorial, we will show you how to handle exceptions in Spring Boot REST API application. Dependencies. Data access using JDBC. You have a transactional method, and you need to save into ES after this transactional method call has succeeded and committed the transaction. class}) if you need rollback on some checked exception. support . Description. Add @ControllerAdvice annotation at class level. Aug 3, 2022 · Today we will look into Spring Exception Handling using @ExceptionHandler, @ControllerAdvice and HandlerExceptionResolver. myproject. catch. xml. And the mysql-connector-java dependency is required to work with MySQL database. When an exception condition occurs, an exception is thrown. Overview. services. g. @ControllerAdvice @ControllerAdvice is a specialization of the @Component annotation which Oct 16, 2023 · Global exception handler is a common exception handler for more than one Spring controllers. Configuration Options. Declare dependency for MySQL JDBC Driver. September 2nd, 2018 | Spring Boot. Handling the Exceptions. 5 NamedParameterJdbcTemplate. getCause until a null value is returned. create customException handler extend ResponseEntityExceptionHandler . 11. 0</version>. A reference to any chained exceptions. ServletException and IOException , let’s see what happens when we throw these exception from our application. The @ ExceptionHandler annotation is used to detect certain runtime exceptions and send responses according to the exception. Jun 28, 2018 · Field jdbcTemplate in com. Another frequently encountered caveat I know: public void a() {. Open the connection. @PersistenceContext. ) Then provide a username and a password to connect to the database. xml: 3. Exception Handler Examples in Spring REST Controller. Spring Boot JDBC has a level of control over the SQL queries that are being written. Dec 31, 2020 · Below are the details for connecting to MySQL server in a Spring Boot application. We take an opinionated view of the Spring platform and third-party libraries, so that you can get started with minimum fuss. Using Exception handling, we can handle the SQL Exception like we handle the normal exception. Remember the order of the @ExceptionHandlers matters — once it matches to one exception, it will not continue to check following handlers. Side note: you are using an old version of the driver. Mar 15, 2019 · 1. try. In this article we’ll Spring Mvc project to Java Exception Handling Tutorial. For the exception handling and the "translation", you could do something like what Spring does (see the various JpaDialect classes, e. Spring Boot simplifies the process of switching between RDBMS. Exceptions that occur due to the Database or Driver come under SQL Exception. The problem I face is that the application throws a hibernate exception : Unable to acquire JDBC Connection I get this e Jun 15, 2022 · 0. Design Patterns 12. It covers topics such as data source configuration, transaction management, exception handling, and query execution. April 4, 2024 by Spring Java. Hibernate Exception Overview. println("ERROR: Fetch statement failed: " +. How to handle exceptions in Spring MVC . You cannot add any arbitrary one (like you tried with the MySQL driver as that requires a running instance of MySQL and needs proper configuration). Step 1: Create a Dynamic Web Project with a name SpringMVCExecptionApp and create a package com. The main goal of Spring Boot is to reduce Apr 20, 2021 · Database connection exception handling with Spring. In this quick tutorial, we’ll learn how to use the Spring session JDBC to persist session information to a database. This is fine. The main topics we are going to discuss here are, Create a Sep 8, 2021 · Hi I am new to spring boot. In this example application, we can customize the exception and return a JSON response that can be understandable for the consumers of REST API. The most generic catch clause is the following one: catch (SQLException e) {. JdbcTemplate is the central class in the JDBC core package. Spring Exception Handling Mar 21, 2016 · Table of Contents Overview @ExceptionHandler @ControllerAdvice ExceptionHandlerResolver Handle the Access Denied in Spring Security Summary 1. Spring Data REST. In the last post, we had added the functionality to read, create and update records using our application. Collections 9. Dec 31, 2019 · set @errorMessage = error_message() set @errorSeverity = error_severity() set @errorState = error_state() raiserror(@errorMessage,@errorSeverity,@errorState) end catch. From my point of view you should verify yourself if an user with that username already exists before trying to create it. System. Whether you use spring-data-jpa inside that transactional method or not is irrelevant. The try block must be followed by either catch or finally. And add @ExceptionHandler annotation for each exception you want to handle. JDBC produces a lot of boiler plate code, such as opening/closing a connection to a database, handling sql exceptions etc. In this post, we will look at exception handling in a Spring Boot application. The biggest takeaway should be, that it does not matter which framework you are using in the end, it is all about the JDBC basics. batchUpdate ORA-01000. Jan 23, 2017 · This hierarchy takes care of all the exception that are thrown by JDBC, Hibernate, other ORM implemntations, and JPA, etc. Aug 8, 2023 · Spring Boot is an open-source Java framework used to create a Micro Service. 10. public class GlobalExceptionHandler {. This is a complete beginner-to-expert in-depth exception handling tutorial in Java. validation. public List<Invoice> getByDate(String Spring Framework Reference provides a comprehensive guide on how to use JDBC for data access with Spring. jdbc. Inside my tasklet I query on two datasources, first query on ds1 goes right, second query on ds2 goes wrong: Apr 4, 2024 · Global Exception Handling in the Spring Boot Rest API. As always, the code presented in this article is available over on GitHub. Keyword. Next, provide a URL that varies between JDBC drivers. Miscellaneous 10. properties file under the src/main/resources directory with the following content: Aug 24, 2021 · Handling Exception 5. Jan 16, 2012 · 4. In this tutorial, we will learn how to handle exceptions in Spring Boot. Spring JDBC templates throws back an EmptyResultDataAccessException exception if it doesn't find the data in the database. I have configured spring batch to use a different datasource than default "spring. If you want more information, check this. These can be mapping errors, infrastructure problems, SQL errors, data integrity violations, session problems, and transaction errors. @ResponseStatus(value= HttpStatus. e. Proper exception handling helps ensure that your application is stable Nov 1, 2017 · Whether you use spring-data-jpa or not is irrelevant. return HttpStatus. This annotation is used to define a method that will handle exceptions of a specific type. getMessage()); } With this code you are printing the exception. While working with database using plain old JDBC, it becomes cumbersome to write unnecessary code to handle exceptions, opening and closing database connections, etc. Action: Consider defining a bean of type 'org. Spring JdbcTemplate batchUpdate handling exceptions. The code example that you have given will only catch exceptions that are thrown in the flow of a REST call. microsoft. mysql. Spring Boot JDBC has simplified the work of Spring JDBC by automating the work and steps by using the concept of Dec 31, 2020 · Spring Boot provides some properties with which we can add the exception message, exception class, or even a stack trace as part of the response payload: server: error: include-message: always include-binding-errors: always include-stacktrace: on_trace_param include-exception: false. Using JdbcTemplate. SQLException is available in the java. Default Exception Handling with Spring Boot. JdbcService required a bean of type 'org. Exceptions that occur during the compile time are checked exceptions. Many of the spring-data exceptions are thrown after the REST calls return during database commit. The following table describes each. class, Exception2. From the SpringSource Site: Common data access exceptions. Apis help to create, retrieve, update, delete Tutorials. Hello, in this article, we will create an Exception Handling mechanism for use in a Spring Boot project. dineshonjava. asm-3. This annotation can be used to handle the exception at the controller level. Use @Transactional(rollbackFor={CustomCheckedException. Implementing JDBC in the Spring Framework takes care of working with many low-level operations (opening/closing connections, executing SQL Dec 31, 2022 · 2. Specify the fully qualified classname of the JDBC driver so that the DriverManager can load the driver class. Dec 22, 2017 · 1. This article covers various ways in which exceptions can be handled in a Spring Boot Project. At a high level, Spring creates proxies for all the classes annotated with @Transactional, either on the class or on any of the methods. when I enter an email that already exists, it shows me the message. It handles the creation and release of resources, which helps you avoid common errors, such as forgetting to close the connection. The value-add provided by the Spring Framework's JDBC abstraction framework is perhaps best shown by the following list (note that only the italicized lines need to be coded by an application developer): Define connection parameters. Sep 20, 2018 · My Spring Boot works fine when I generate report using Japser report. Step 2: Add below mentioned Spring 3. Microsoft has open sourced the SQL Server JDBC driver and it is available on maven as: <groupId>com. This article discussed several ways to implement an exception handling mechanism for a REST API in Spring, starting with the older mechanism and continuing with the Spring 3. In Spring Boot JDBC, the database related beans such as DataSource, JdbcTemplate, and NamedParameterJdbcTemplate auto-configures and created during the startup. The org. JDBC 8. Other Spring Boot Tutorials: Spring Boot automatic restart using Spring Boot DevTools; Spring Boot Form Handling Tutorial with Spring Form Tags and JSP; How to create a Spring Boot Web Application (Spring MVC with JSP/ThymeLeaf) Spring Boot - Spring Data JPA - MySQL Example Aug 23, 2016 · And even if you configured all correctly, transactions are only rolled back on unchecked exceptions by default. Spring Boot Exception Handling: This guide helps you to understand how to define generic/global exception handlers in spring boot application. Servlet Exception If you notice, doGet() and doPost() methods throw javax. His expertise areas are Java & J2EE 12. intValue()); } catch (Exception e) {. In a Spring application with REST APIs, an exception handler method should be annotated with @ExceptionHandler, @ResponseStatus and @ResponseBody Apr 12, 2022 · Exception handlers you saw above can be defined on a controller-advice class – but now they apply to exceptions thrown from any controller. PersistenceExceptionTranslator implementation(s) in your configuration files. Table 12. // Your Code. JdbcTemplate throws an exception. Mar 24, 2022 · How to handle exceptions in Spring MVC . <version>10. org. consumer errors). The @ControllerAdvice is the specialization of @Component stereotype annotation. Introduction. dao. Here is a simple example: @ControllerAdvice. Overview Here we are going describe how to implement Exception Handling with Spring for a REST API. SQLServerDriver (note the switch of order between sqlserver and jdbc. To use MySQL JDBC driver, declare the following dependency in the Maven pom. All this is not nice, this code won't be portable and finding what attribute(s) caused the violation won't be easy. It is a good practice to handle exceptions and errors in APIs. To replace an ErrorHandler or ConsumerAwareErrorHandler implementation, you should implement handleOne() and leave seeksAfterHandle() to return false (default). AWS EC2s with auto-scaling groups) then you could run into race-conditions and still end up causing the database constraint violation to be thrown. If you don't get leaks detected (at least make sure you don't leak connections check if you are messing around with Connections yourself). core package contains the JdbcTemplate class and its various callback interfaces, plus a variety of related classes. hv sx by lf dc qw by tb rb dr