集成mybatis

引入数据库连接池、mysql驱动，mybatis，pagehelper分页，generator逆向生成代码等依赖

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.0</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>
        <!--mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!--mapper -->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>1.1.4</version>
        </dependency>
        <!--pagehelper -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>RELEASE</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>1.3.2</version>
            <scope>compile</scope>
            <optional>true</optional>
        </dependency>

generator逆向生成代码
先在根目录下新建generatorConfig.xml文件，文件内容如下

<generatorConfiguration>
    <context id="MysqlContext" targetRuntime="MyBatis3Simple" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>

        <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
            <property name="mappers" value="com.zwq.utils.MyMapper"/>
        </plugin>

        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/hrm_db"
                        userId="root"
                        password="123456">
        </jdbcConnection>

        <!-- 对于生成的pojo所在包 -->
        <javaModelGenerator targetPackage="com.zwq.entity" targetProject="src/main/java"/>

        <!-- 对于生成的mapper所在目录 -->
        <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources"/>

        <!-- 配置mapper对应的java映射 -->
        <javaClientGenerator targetPackage="com.zwq.mapper" targetProject="src/main/java"
                             type="XMLMAPPER"/>


        <table tableName="dept_inf"></table>
        <table tableName="document_inf"></table>
        <table tableName="employee_inf"></table>
        <table tableName="job_inf"></table>
        <table tableName="menu_inf"></table>
        <table tableName="notice_inf"></table>
        <table tableName="user_inf"></table>

    </context>
</generatorConfiguration>

在java空间新建utils包，自定义MyMapper类继承 Mapper<T>, MySqlMapper<T>，再自定义逆向工程启动类GeneratorDisplay

public void generator() throws Exception{

       List<String> warnings = new ArrayList<String>();
       boolean overwrite = true;
       //指定 逆向工程配置文件
       File configFile = new File("generatorConfig.xml");
       ConfigurationParser cp = new ConfigurationParser(warnings);
       Configuration config = cp.parseConfiguration(configFile);
       DefaultShellCallback callback = new DefaultShellCallback(overwrite);
       MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config,
               callback, warnings);
       myBatisGenerator.generate(null);

   }

   public static void main(String[] args) throws Exception {
       try {
           GeneratorDisplay generatorSqlmap = new GeneratorDisplay();
           generatorSqlmap.generator();
       } catch (Exception e) {
           e.printStackTrace();
       }

   }

通过运行main方法就可以生成我们所需要的mapper,entity等文件了，
由于使用了公共的Mapper接口，我们可以像JPA一样使用一些默认方法操作增删改查。

mybatis配置

先配置数据源，然后在application.properties中增加

mybatis.type-aliases-package=com.zwq.entity
mybatis.mapper-locations=classpath:mapper/*.xml

mapper.mappers=com.zwq.utils.MyMapper
mapper.not-empty=false
mapper.identity=MYSQL
pagehelper.helperDialect=mysql
pagehelper.reasonable=true
pagehelper.supportMethodsArguments=true
pagehelper.params.count=countSql

启动类中添加mybatis的mapper包扫描@MapperScan(basePackages = "com.zwq.mapper")

Service的创建

新建一个HrmService接口，我们先写一些和UserInf相关的内容，方法如下

/**
     * 用户登录
     * @param loginname
     * @param password
     * @return
     */
    UserInf login(String loginname, String password);

    /**
     * 根据id 查询用户
     * @param id
     * @return
     */
    UserInf findUserById(Integer id);

    /**
     * 获得所有用户（分页）
     * @param user
     * @param page
     * @param pageSize
     * @return
     */
    List<UserInf> findUser(UserInf user,Integer page, Integer pageSize);

    /**
     * 根据id删除用户
     * @param id
     */
    void removeUserById(Integer id);

    /**
     * 修改用户
     * @param user
     */
    void modifyUser(UserInf user);

    /**
     * 添加用户
     * @param user
     */
    void addUser(UserInf user);

然后依次写实现，由于使用了公共Mapper，单表的操作及其的简单
我们可以直接用userInfMapper去调用相关方法，值得注意的是，分页接口，只需要一开始调用PageHelper.startPage(page, pageSize);即可实现分页功能，十分方便，分页代码如下

@Override
    public List<UserInf> findUser(UserInf user, Integer page, Integer pageSize) {
        PageHelper.startPage(page, pageSize);
        Example example = new Example(UserInf.class);
        Example.Criteria criteria = example.createCriteria();
        if (!StringUtils.isEmptyOrWhitespace(user.getUsername())) {
            criteria.andLike("username", "%" + user.getUsername() + "%");
        }

        return userInfMapper.selectByExample(example);
    }

测试结果