[Java知识库]Springboot整合c3p0和mybatis

1.新建springboot项目

?2.打开项目列表，找到pom.xml文件，导入mybatis,c3p0,mysql依赖文件

粘贴以下内容至dependencies标签内

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.2</version>
</dependency>
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.2</version>
</dependency>
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

3.在src/main/resources目录下建立application-c3p0.propertis文件内容如下

spring.datasource.c3p0.driverClass=com.mysql.cj.jdbc.Driver
spring.datasource.c3p0.jdbcUrl=jdbc:mysql://localhost:3306/数据库名?serverTimezone=Asia/Shanghai&useSSL=false&zeroDateTimeBehavior=convertToNull&useLegacyDatetimeCode=false
spring.datasource.c3p0.user=用户名
spring.datasource.c3p0.password=密码

spring.datasource.c3p0.initialPoolSize=5
spring.datasource.c3p0.minPoolSize=5
spring.datasource.c3p0.maxPoolSize=10
spring.datasource.c3p0.acquireIncrement=5

4.在src/main/resources目录下建立mybatis-config.xml文件内容如下

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!-- 全局映射器启用缓存 -->
        <setting name="cacheEnabled" value="true"/>
        <!-- 对于未知的SQL查询，允许返回不同的结果集以达到通用的效果-->
        <setting name="multipleResultSetsEnabled" value="true"/>
        <!-- 允许使用列标签代替列名 -->
        <setting name="useColumnLabel" value="true"/>
        <!-- 允许使用自定义的主键值(比如由程序生成的UUID 32位编码作为键值)，数据表的PK生成 -->
        <setting name="useGeneratedKeys" value="true"/>
        <!-- 对于批量更新操作缓存SQL以提高性能  -->
        <setting name="defaultExecutorType" value="SIMPLE"/>
        <!-- 数据库超过25000秒仍未响应则超时 -->
        <setting name="defaultStatementTimeout" value="25000"/>
        <!--开启驼峰式命名规则映射-->
        <setting name="mapUnderscoreToCamelCase" value="true" />
    </settings>
</configuration>

5.在application.propertis文件中添加

spring.profiles.active=c3p0
mybatis.mapperLocations=classpath:mappers/*.xml
mybatis.configLocation=classpath:mybatis-config.xml

6.在src/main/java下创建包，包名为config,创建名为DataSourceConfiguration的类内容如下

@Configuration//声明为配置类
public class DataSourceConfiguration {
    @Bean(name = "dataSource")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.c3p0")
    public DataSource createDataSource() {
        return DataSourceBuilder.create() // 创建数据源构建对象
                .type(ComboPooledDataSource.class) // 设置数据源类型
                .build(); // 构建数据源对象
    }
}

7.如果你的mapper.xml在、src/main/java的目录下，请在pom.xml文件的bulid标签内复制如下内容

<resources>
<resource>
    <directory>src/main/java</directory>
    <includes>
        <include>**/*.xml</include>
    </includes>
    <filtering>true</filtering>
</resource>
<resource>
    <directory>src/main/resources</directory>
    <includes>
        <include>**/*.xml</include>
        <include>**/*.properties</include>
    </includes>
    <filtering>true</filtering>
</resource>
</resources>

8.建立你的实体类包，mapper类的包，例如下

?这里切记，mapper包里面的**.xml和**接口的**要一致，否则会org.apache.ibatis.binding.BindingException: Invalid bound statement (not found)

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