jdbctemplate

Spring数据访问和事务

梦想的初衷 提交于 2019-12-20 14:07:26
1、模型 2、解耦 3、实现 3.1 核心接口 3.2 代码分析 3.2.1 事务管理 3.2.2 数据访问 4、使用 4.1 编程模式 4.2 配置模式 4.2.1 声明式配置方式 4.2.2 注解式配置方式 5、总结 1、模型 在一般的编程习惯中,Spring的数据访问和事务处理的层次结构归纳如下图所示: 图. 1 2、解耦 Spring事务作为一个独立的组件,其目的就是为了与数据访问组件进行分离,这也是Spring事务框架设计的原则。根据这一职责清晰的原则,Spring在设计时就对事务和数据访问进行了很好的职责划分,这个可以从spring-tx和spring-jdbc这两个包就可以看出来。 但是在实际的代码中,会遇到一个棘手的问题:事务和数据访问操作都需要同一个数据库连接资源,那么它们之间怎么传递呢? 这里涉及三个方面:一是线程安全,二是资源的唯一性,三是事务和数据访问的解耦。 图. 2 在图2中的1、2和3这三个地方都需要使用数据库连接,并且是同一个连接。Spring的做法是将该连接放在一个统一的地方,要使用该资源,都从这个地方获取,这样就解决了事务模块和数据访问模块之间的紧耦合。 解除耦合之后,对于不同的ORM技术,则需要提供不同的事务管理实现,如下图所示: 图. 3 3、实现 3.1 核心接口 Spring事务框架的核心接口是:TransactionDefinition

Multiple JdbcTemplate instances or not?

血红的双手。 提交于 2019-12-20 11:32:13
问题 From what I understand, both DataSource and JdbcTemplates are threadsafe , so you can configure a single instance of a JdbcTemplate and then safely inject this shared reference into multiple DAOs (or repositories) . Also DataSource should be a Spring singleton, since it manages the connection pool. The official Spring Documentation JdbcTemplate best practices explains the alternatives (excerpts from the manual are in italics, and my notes between square brackets: configure a DataSource in

使用Spring的jdbcTemplate进一步简化JDBC操作

☆樱花仙子☆ 提交于 2019-12-20 01:29:17
spring 第一篇(1-1):让java开发变得更简单(下) 这个波主虽然只发了几篇,但是写的很好 上面一篇文章写的很好,其中提及到了 Spring的jdbcTemplate ,templet方式我之前已经有点了解了,但是Spring的还不知道,这次真的又学到了Spring的 使用Spring的jdbcTemplate进一步简化JDBC操作 配置文件 Spring mvc中jdbcDaoSupport和jdbcTemplate的使用 [java] view plain copy print ? package xm.zjl.dao; import java.util.ArrayList; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.stereotype.Repository; /** * 测试标签dao * * @author zjl * */ @Repository public class TagTestDao{ @Autowired private JdbcTemplate

org.springframework.web.util.NestedServletException: Request processing failed

情到浓时终转凉″ 提交于 2019-12-19 10:30:46
问题 I am doing CRUD using spring jdbc template. insert,select and delete operations are working fine but I got these following exception in update process. org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [java.lang.Integer]: No default constructor found; nested exception is java.lang.NoSuchMethodException: java.lang.Integer.<init>() here is my controller:

org.springframework.web.util.NestedServletException: Request processing failed

一个人想着一个人 提交于 2019-12-19 10:30:14
问题 I am doing CRUD using spring jdbc template. insert,select and delete operations are working fine but I got these following exception in update process. org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [java.lang.Integer]: No default constructor found; nested exception is java.lang.NoSuchMethodException: java.lang.Integer.<init>() here is my controller:

How to call a stored procedure with ref cursor as an output parameter using Spring?

半城伤御伤魂 提交于 2019-12-19 04:25:31
问题 I have a stored procedure which has body like :- PROCEDURE PROC_NAME(param1 in varchar2,param2 in varchar2,results_cursor OUT CURSOR_TYPE); Each row of result is equivalent to an instance of a certain user defined class. How can I call this in Spring. I went through lot of google and stackoverflow but could not find an apt answer. Can anyone please provide me a solution to this. Thanks in advance. 回答1: Here's something I put together based on this StackOverflow question and the Spring

Spring事务管理

岁酱吖の 提交于 2019-12-19 04:07:55
Spring事务管理分为 声明式事务管理 和 编程式事务 管理,声明式事务管理又分为 xml 和 注解 两种配置方式。应该优先选择声明式事务,因为声明式事务对程序代码的影响最小,因此最符合 非侵入式轻量级容器 的理想 。只有在进行少量事务操作时,才应该选择编程式事务管理的方式。 声明式事务管理 xml配置方式 Spring配置文件: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans

How exactly work the Spring RowMapper interface?

核能气质少年 提交于 2019-12-18 13:23:35
问题 I am studying for the Spring Core certification and I have some doubts about how Spring handle the JDBC queries: So I know that I can obtain data from my DB tables in various ways depending on the type of data that I expect to obtain: 1) Query for simple type (as an int, a long or a String): I use the queryForObject() method of the jdbcTemplate class, something like it: String sql = "SELECT count(*) FROM T_REWARD"; int rowsNumber = jdbcTemplate.queryForObject(sql, Integer.class); So to obtain

JPA vs Spring JdbcTemplate

纵饮孤独 提交于 2019-12-18 09:55:10
问题 For a new project is JPA always the recommended tool for handling relational data or are there scenarios where Spring JdbcTemplate is a better choice? Some factors to consider in your response: new database schema vs pre-existing schema and tables level of developer expertise ease with which can integrate with a data caching layer performance any other relevant factors to consider? 回答1: Use Spring JdbcTemplate if you don't want to access your database schema via a domain model. Using

Explicit type conversion between child spring object, and it's super java.util object

十年热恋 提交于 2019-12-18 09:35:06
问题 In spring I am using jdbcTemplate, but having a problem that it is returning a Linkedcaseinsensitivemap when querying for a List, when doing the following I still get the spring linkedcaseinsensitivemap, even if I cast it to java util List and define the left-side of the assignment as a java.util.List. Firstly how is that even possible? final java.util.List<Map<String, Object>> list = (java.util.List<Map<String, Object>>) jdbc .queryForList("SELECT * FROM customer"); so, how would one achive