2023-01-18
一、定义切面优先级
1、语法:@Order(value=index)
①index是int类型,默认值是int可存储的最大值
②数值越小,优先级越高
二、Spring中的JdbcTemplate
1、JdbcTemplate简介
(1)Spring提供的JdbcTemplate是一个小型持久化层框架,简称Jdbc代码
Mybatis是一个半自动化的ORM持久化层框架
2、JdbcTemplate基本使用
(1)导入Jar包
<dependencies> <!-- https://mvnrepository.com/artifact/org.springframework/spring-context --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.3.10</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.3.10</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>5.3.10</version> </dependency> <!-- https://mvnrepository.com/artifact/com.alibaba/druid --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.10</version> </dependency> <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.26</version> </dependency> <!-- https://mvnrepository.com/artifact/junit/junit --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> </dependencies>
(2)编写配置文件
db.properties:设置连接数据库属性
applicationContext.xml(spring配置文件)
加载外部属性文件、装配数据源(DataSources)、装配JdbcTemplate
<?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:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <!-- 加载外部属性文件--> <context:property-placeholder location="classpath:db.properties"></context:property-placeholder> <!-- 装配数据源(DataSources)--> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"> <property name="driverClassName" value="${db.driverClassName}"></property> <property name="url" value="${db.url}"></property> <property name="username" value="${db.username}"></property> <property name="p