SpringBoot（十二）：SpringBoot整合Mybatis-Plus

本節版本雖然只用到了基本特性，但能夠知足大部分的增刪改查。

1、環境準備
SpringBoot 1.5.10.RELEASE
Mybatis-Plus 2.1.9
Mybatis-Plus 官方地址：http://mp.baomidou.com/

pom依賴，爲了方便，全貼出來吧：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cn.demo</groupId>
  <artifactId>spriingboot_mybatis_plus</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <log4j.version>1.3.8.RELEASE</log4j.version>
        <druid.version>1.0.26</druid.version>
        <mybatis-plus.version>2.1.9</mybatis-plus.version>
        <mybatisplus-spring-boot-starter.version>1.0.5</mybatisplus-spring-boot-starter.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <!-- druid數據庫鏈接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>

        <!-- mysql connector -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- Mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatisplus-spring-boot-starter</artifactId>
            <version>${mybatisplus-spring-boot-starter.version}</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2、項目結構

先列出最初始的項目結構，至於model，mapper，service，mapper xml，controller以後都自動生成出來。

 

 

3、代碼詳情
數據準備

在test庫建一個user表。

CREATE TABLE `user` (
`id` bigint(20) NOT NULL COMMENT '用戶ID',
`name` varchar(50) DEFAULT NULL COMMENT '用戶名',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用戶表'

insert into `user` (`id`, `name`) values('1','張三');
insert into `user` (`id`, `name`) values('2','李四');
insert into `user` (`id`, `name`) values('3','王五')

application.yml:

spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://192.168.1.20:3306/test
 username: root password: root123 mybatis-plus: # 若是是放在src/main/java目錄下 classpath:/com/yourpackage/*/mapper/*Mapper.xml # 若是是放在resource目錄 classpath:/mapper/*Mapper.xml mapper-locations: classpath:mybatis/mappers/*Mapper.xml #實體掃描，多個package用逗號或者分號分隔 typeAliasesPackage: cn.demo.model global-config: #主鍵類型 0:"數據庫ID自增", 1:"用戶輸入ID",2:"全局惟一ID (數字類型惟一ID)", 3:"全局惟一ID UUID"; id-type: 0 #字段策略 0:"忽略判斷",1:"非 NULL 判斷"),2:"非空判斷" field-strategy: 1 #駝峯下劃線轉換 #db-column-underline: true #刷新mapper 調試神器 refresh-mapper: true #數據庫大寫下劃線轉換 #capital-mode: true #Sequence序列接口實現類配置 #key-generator: com.baomidou.mybatisplus.incrementer.OracleKeyGenerator #邏輯刪除配置（下面3個配置） #logic-delete-value: 1 #logic-not-delete-value: 0 #sql-injector: com.baomidou.mybatisplus.mapper.LogicSqlInjector #自定義填充策略接口實現 #meta-object-handler: com.baomidou.springboot.MyMetaObjectHandler configuration: map-underscore-to-camel-case: true cache-enabled: false #配置JdbcTypeForNull jdbc-type-for-null: 'null' logging.level.com.demo.mapper: debug

druid.properties:

#-------------------------- # 下面爲鏈接池的補充設置，應用到上面全部數據源中 # 初始化大小，最小，最大 spring.datasource.initialSize=5 spring.datasource.minIdle=1 spring.datasource.maxActive=50 # 配置獲取鏈接等待超時的時間 spring.datasource.maxWait=60000 # 配置間隔多久才進行一次檢測，檢測須要關閉的空閒鏈接，單位是毫秒 spring.datasource.timeBetweenEvictionRunsMillis=60000 # 配置一個鏈接在池中最小生存的時間，單位是毫秒 spring.datasource.minEvictableIdleTimeMillis=300000 spring.datasource.validationQuery=SELECT 1 FROM DUAL spring.datasource.testWhileIdle=true spring.datasource.testOnBorrow=false spring.datasource.testOnReturn=false # 打開PSCache，而且指定每一個鏈接上PSCache的大小 spring.datasource.poolPreparedStatements=false #spring.datasource.maxPoolPreparedStatementPerConnectionSize=20 # 配置監控統計攔截的filters，去掉後監控界面sql沒法統計，'wall'用於防火牆 spring.datasource.filters=stat,wall,log4j # 經過connectProperties屬性來打開mergeSql功能；慢SQL記錄 spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 # 合併多個DruidDataSource的監控數據 #spring.datasource.useGlobalDataSourceStat=true

DruidConfiguration.java

因爲這裏不用controller接口方式演示，使用test演示，沒引入starter-web，因此druid的servlet暫時註釋，有要用的能夠打開，加入依賴便可。

package cn.demo.config; import com.alibaba.druid.pool.DruidDataSource; import com.alibaba.druid.support.http.StatViewServlet; import com.alibaba.druid.support.http.WebStatFilter; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.boot.web.servlet.FilterRegistrationBean; import org.springframework.boot.web.servlet.ServletRegistrationBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.PropertySource; import javax.sql.DataSource; /** * @ClassName cn.saytime.config.DruidConfiguration * @Description */ @Configuration @PropertySource(value = "classpath:druid.properties") public class DruidConfiguration { @Bean(destroyMethod = "close", initMethod = "init") @ConfigurationProperties(prefix = "spring.datasource") public DataSource druidDataSource() { return new DruidDataSource(); } //
// /** // * 註冊一個StatViewServlet // * // * @return // */ // @Bean // public ServletRegistrationBean druidStatViewServlet() { //      //org.springframework.boot.context.embedded.ServletRegistrationBean提供類的進行註冊. // ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*"); //
//      //添加初始化參數：initParams //      //白名單： // servletRegistrationBean.addInitParameter("allow", "127.0.0.1"); //      //IP黑名單 (存在共同時，deny優先於allow) : 若是知足deny的話提示:Sorry, you are not permitted to view this page. //// servletRegistrationBean.addInitParameter("deny", "192.168.1.73"); //      //登陸查看信息的帳號密碼. // servletRegistrationBean.addInitParameter("loginUsername", "admin"); // servletRegistrationBean.addInitParameter("loginPassword", "123456"); //      //是否可以重置數據. // servletRegistrationBean.addInitParameter("resetEnable", "false"); // return servletRegistrationBean; // } //
// /** // * 註冊一個：filterRegistrationBean // * // * @return // */ // @Bean // public FilterRegistrationBean druidStatFilter() { //
// FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter()); //
//      //添加過濾規則. // filterRegistrationBean.addUrlPatterns("/*"); //
//      //添加不須要忽略的格式信息. // filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"); // return filterRegistrationBean; // }
 }

MybatisConfiguration.java :注意這裏的MapperScan，換成你項目mapper文件夾路徑

package cn.demo.config; import com.baomidou.mybatisplus.plugins.PaginationInterceptor; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * @author zh * @ClassName cn.saytime.config.MybatisConfiguration * @Description */ @Configuration @MapperScan("cn.demo.mapper*") public class MybatisConfiguration { /* * 分頁插件，自動識別數據庫類型 * 多租戶，請參考官網【插件擴展】 */ @Bean public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); } /* * oracle數據庫配置JdbcTypeForNull * 參考：https://gitee.com/baomidou/mybatisplus-boot-starter/issues/IHS8X 不須要這樣配置了，參考 yml: mybatis-plus: confuguration dbc-type-for-null: 'null' @Bean public ConfigurationCustomizer configurationCustomizer(){ return new MybatisPlusCustomizers(); } class MybatisPlusCustomizers implements ConfigurationCustomizer { @Override public void customize(org.apache.ibatis.session.Configuration configuration) { configuration.setJdbcTypeForNull(JdbcType.NULL); } } */ }

自動生成代碼工具類Generator.java(換成數據庫連接以及輸出路徑便可。)

package cn.demo.utils; import com.baomidou.mybatisplus.generator.AutoGenerator; import com.baomidou.mybatisplus.generator.config.DataSourceConfig; import com.baomidou.mybatisplus.generator.config.GlobalConfig; import com.baomidou.mybatisplus.generator.config.PackageConfig; import com.baomidou.mybatisplus.generator.config.StrategyConfig; import com.baomidou.mybatisplus.generator.config.rules.DbType; import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy; //根據表名自動生成java文件
public class Generator { public static void main(String[] args) { String packageName = "cn.demo"; boolean serviceNameStartWithI = false; generateByTables(serviceNameStartWithI, packageName, "li", "test", "user");//li做者。test數據庫名。user表名。
        System.out.println("completed..."); } /** * @param serviceNameStartWithI * @param packageName 包名 * @param author 做者 * @param database 數據庫名 * @param tableNames 表名 */
    private static void generateByTables(boolean serviceNameStartWithI, String packageName, String author, String database, String... tableNames) { GlobalConfig config = new GlobalConfig(); String dbUrl = "jdbc:mysql://192.168.1.20:3306/" + database + "?useUnicode=true&characterEncoding=utf8&autoReconnect=true&useSSL=false"; DataSourceConfig dataSourceConfig = new DataSourceConfig(); dataSourceConfig.setDbType(DbType.MYSQL) .setUrl(dbUrl) .setUsername("root") .setPassword("root123") .setDriverName("com.mysql.jdbc.Driver"); StrategyConfig strategyConfig = new StrategyConfig(); strategyConfig .setCapitalMode(true) .setEntityLombokModel(false) .setDbColumnUnderline(true) .setNaming(NamingStrategy.underline_to_camel) // .setSuperMapperClass("cn.saytime.mapper.BaseMapper")
                .setInclude(tableNames);//修改替換成你須要的表名，多個表名傳數組
        config.setActiveRecord(false) .setAuthor(author) .setOutputDir("e:\\codeGen")//生成的java到文件夾下
                .setFileOverride(true) .setEnableCache(false); if (!serviceNameStartWithI) { config.setServiceName("%sService"); } new AutoGenerator().setGlobalConfig(config) .setDataSource(dataSourceConfig) .setStrategy(strategyConfig) .setPackageInfo( new PackageConfig() .setParent(packageName) .setController("web")//生成的代碼到文件夾下cn.demo.web
                                .setEntity("model") .setMapper("mapper") .setService("service") .setServiceImpl("service.impl") .setXml("mybatis.mappers") ).execute(); } }

4、自動生成代碼

執行Generator Main方法，到輸出路徑，能夠看到代碼文件已經生成好了:

 

 將model,mapper,service拷貝到cn.demo目錄下，將mybatis/mappers文件夾拷貝到src/main/resources目錄下.

5、測試

SpringbootMybatisPlusApplicationTests.java

package cn.demo; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.context.SpringBootTest; import org.springframework.test.context.junit4.SpringRunner; import cn.demo.model.User; import cn.demo.service.UserService; import java.util.List; @RunWith(SpringRunner.class) @SpringBootTest public class SpringbootMybatisPlusApplicationTests { @Autowired private UserService userService; @Test public void contextLoads() { // 全部用戶
        List<User> users = userService.selectList(null); System.out.println(users); //查詢id=1的用戶
        User user = userService.selectById(1); System.out.println("users1=="+user); } }

輸出結果：

 

 

6、更多使用方式
列舉幾種經常使用的增刪改查方式，其實最快的方式就是去官網看示例。

查詢id=1的用戶
User user = userService.selectById(1);

查詢name=張三的用戶
User user = userService.selectOne(new EntityWrapper<User>().eq("name", "張三"));

查詢id>1的用戶
List<User> userList = userService.selectList(new EntityWrapper<User>().gt("id", 1));
修改id=1的用戶名
User user = userService.selectById(1);
user.setName("張三2");
boolean b = userService.updateById(user);

添加用戶
User user = new User();
user.setName("趙六");
boolean insert = userService.insert(user);

刪除用戶
boolean b = userService.deleteById(1);

分頁查詢用戶
查詢id>1 每頁一條數據，第二頁，也就是第三條數據。

Page<User> userPage = new Page<>();

userPage.setCurrent(2);userPage.setSize(1);userService.selectPage(userPage, new EntityWrapper<User>().gt("id", 1));List<User> userList = userPage.getRecords();System.out.println(userList);[User{, id=3, name=王五}]