springboot:mybatis&druid&pagehelper

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pom.xml
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<!-- Spring Boot Web 依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- Spring Boot Test 依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- Junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <!-- db start -->
        <!-- Spring Boot Mybatis 依赖 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis-spring-boot}</version>
        </dependency>

        <!-- MySQL 连接驱动依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-connector}</version>
        </dependency>

        <!-- Druid 数据连接池依赖 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid}</version>
        </dependency>

        <!--分页插件-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>4.1.1</version>
        </dependency>
        <!-- db end -->
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application.xml
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spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://host:port/db?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&zeroDateTimeBehavior=convertToNull
spring.datasource.username=name
spring.datasource.password=psd
# 初始化大小，最小，最大
spring.datasource.initialSize=5
spring.datasource.minIdle=5
spring.datasource.maxActive=20
# 配置获取连接等待超时的时间
spring.datasource.maxWait=60000
# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
spring.datasource.timeBetweenEvictionRunsMillis=60000
# 配置一个连接在池中最小生存的时间，单位是毫秒
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=SELECT 1 FROM DUAL
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
# 打开PSCache，并且指定每个连接上PSCache的大小
spring.datasource.poolPreparedStatements=true
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
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MybatisConfig.java
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package org.spring.springboot.ds;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = MybatisConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MybatisConfig {

    // 精确到 master 目录，以便跟其他数据源隔离
    static final String PACKAGE = "org.spring.springboot.dao";
    static final String MAPPER_LOCATION = "classpath:mapper/*.xml";

    @Value("${spring.datasource.type}")
    private Class<? extends DataSource> dataSourceType;

    @Bean(name="masterDataSource", destroyMethod = "close", initMethod="init")
    @ConfigurationProperties(prefix = "spring.datasource")
    @Primary
    public DataSource dataSource() {
        return DataSourceBuilder.create().type(dataSourceType).build();
    }

    @Bean(name = "masterTransactionManager")
    @Primary
    public DataSourceTransactionManager masterTransactionManager() {
        return new DataSourceTransactionManager(dataSource());
    }

    @Bean(name = "masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(masterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(MybatisConfig.MAPPER_LOCATION));

        //分页插件
        PageHelper pageHelper = new PageHelper();
        Properties props = new Properties();
        props.setProperty("dialect", "mysql");
        props.setProperty("pageSizeZero", "true");
        props.setProperty("reasonable", "false");
        //=============================
        props.setProperty("supportMethodsArguments", "true");
        props.setProperty("returnPageInfo", "check");
        props.setProperty("params", "count=countSql");
        pageHelper.setProperties(props);
        //添加插件
        sessionFactory.setPlugins(new Interceptor[]{pageHelper});

        return sessionFactory.getObject();
    }
}
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CityDao.java
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@Repository
public interface CityDao {

    /**
     * 根据城市名称，查询城市信息
     *
     * @param cityName 城市名
     */
    List<City> findByName(@Param("cityName") String cityName);
}
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CityMapper.xml
resource/mapper/CityMapper.xml
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="org.spring.springboot.dao.CityDao">
<resultMap id="BaseResultMap" type="org.spring.springboot.domain.City">
<result column="id" property="id" />
<result column="province_id" property="provinceId" />
<result column="city_name" property="cityName" />
<result column="description" property="description" />
</resultMap>

<parameterMap id="City" type="org.spring.springboot.domain.City"/>

<sql id="Base_Column_List">
id, province_id, city_name, description
</sql>

<select id="findByName" resultMap="BaseResultMap" parameterType="java.lang.String">
select
<include refid="Base_Column_List" />
from city
where city_name = #{cityName}
</select>

</mapper>
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CityServiceImpl.java
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@Autowired
    private CityDao cityDao;

    public PageInfo findCityByName(String cityName) {

        PageHelper.startPage(1, 10);
        PageInfo<City> page = new PageInfo(cityDao.findByName(cityName));
        return page;
    }