SpringBoot整合系列-整合MyBatis

出处地址：https://www.cnblogs.com/V1haoge/p/9971036.html

    org.mybatis.spring.boot
    mybatis-spring-boot-starter
    1.3.1

application.properties

##配置数据源spring.datasource.url = jdbc:h2:mem:dbtest
spring.datasource.username = sa
spring.datasource.password = sa
spring.datasource.driverClassName =org.h2.Driver

// 该配置类用于配置自动扫描器，用于扫描自定义的mapper接口,MyBatis会针对这些接口生成代理来调用对应的XMl中的SQL@Configuration@MapperScan("com.example.springbootdemo.mapper")public class MyBatisConfig {
}

这个注解必须手动配置是因为mapper接口的位置完全就是用户自定义的，自动配置的时候也不可能找到还不存在的位置。

@Data@NoArgsConstructor@AllArgsConstructor@ToString@EqualsAndHashCode@Builder@ApiModel("书籍模型")public class Book {    @ApiModelProperty(value = "书籍ID", notes = "书籍ID",example = "1")    private Integer bookId;    @ApiModelProperty(value = "书籍页数", notes = "书籍页数",example = "100")    private Integer pageNum;    @ApiModelProperty(value = "书籍名称", notes = "书籍名称",example = "Java编程思想")    private String bookName;    @ApiModelProperty(value = "书籍类型", notes = "书籍类型",hidden = false)    private BookType BookType;    @ApiModelProperty(value = "书籍简介")    private String bookDesc;    @ApiModelProperty(value = "书籍价格")    private Double bookPrice;    @ApiModelProperty(value = "创建时间",hidden = true)    private LocalDateTime createTime;    @ApiModelProperty(value = "修改时间",hidden = true)    private LocalDateTime modifyTime;
}

还有一个枚举类型

public enum BookType {
    TECHNOLOGY,//技术
    LITERARY,//文学
    HISTORY//历史
    ;
}

实体类中使用了swagger2和Lombok中的注解，需要添加对应的jar包

public interface BookRepository {    int addBook(Book book);    int updateBook(Book book);    int deleteBook(int id);    Book getBook(int id);    List getBooks(Book book);
}

    
        INSERT INTO BOOK(        
            PAGE_NUM,        
        
            BOOK_TYPE,        
        
            BOOK_NAME,        
        
            BOOK_DESC,        
        
            BOOK_PRICE,        
            CREATE_TIME,
            MODIFY_TIME)
        VALUES (        
            #{pageNum},        
        
            #{bookType},        
        
            #{bookName},        
        
            #{bookDesc},        
        
            #{bookPrice},        
        sysdate,sysdate)    
    
        UPDATE BOOK SET        
            PAGE_NUM = #{pageNum},        
        
            BOOK_TYPE = #{bookType},        
        
            BOOK_DESC = #{bookDesc},        
        
            BOOK_PRICE = #{bookPrice},        
        
            BOOK_NAME = #{bookName},        
        MODIFY_TIME=sysdate
        WHERe 1=1        
            and BOOK_ID = #{bookId}        
    
    
        delete from BOOK where BOOK_id=#{bookId}    
    
        select * from BOOK where BOOK_ID=#{bookId}    
    
        select * from BOOK WHERe 1=1        
            and BOOK_ID = #{bookId}        
        
            and PAGE_NUM = #{pageNum}        
        
            and BOOK_TYPE = #{bookType}        
        
            and BOOK_DESC = #{bookDesc}        
        
            and BOOK_PRICE = #{bookPrice}        
        
            and BOOK_NAME = #{bookName}        
    
    
        
        
        
        
        
        
        
        
    

在这个配置文件中我们使用了MyBatis的动态SQL和参数映射

application.properties

#配置Xml配置的位置mybatis.mapper-locations=classpath*:/mapper
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, BookType parameter, JdbcType jdbcType) throws SQLException {        int j = 0;        for (BookType bookType : BookType.values()){            if(bookType.equals(parameter)){
                ps.setString(i, j +"");                return;
            }
            j++;
        }
    }    
    @Override
    public BookType getNullableResult(ResultSet rs, String columnName) throws SQLException {        int j = Integer.valueOf(rs.getString(columnName));        if(j >= BookType.values().length) {            return null;
        }        int i = 0;        for(BookType bookType:BookType.values()){            if(j == i){                return bookType;
            }
            i++;
        }        return null;
    }    
    @Override
    public BookType getNullableResult(ResultSet rs, int columnIndex) throws SQLException {        return null;
    }    
    @Override
    public BookType getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {        return null;
    }
}

注意：使用@Mapper注解的时候是不需要添加xml配置Mapper文件的，SQL脚本在接口方法的注解内部定义

@Data@Builder@ToString@EqualsAndHashCode@NoArgsConstructor@AllArgsConstructorpublic class Tree {    private Integer treeId;    private String treeName;    private Integer treeAge;    private Double treeHight;    private TreeType treeType;    private TreeState treeState;    private String treeDesc;
}

@Mapperpublic interface TreeRepository {    
    @Insert("INSERT INTO TREE (TREE_NAME,TREE_AGE,TREE_HIGHT,TREE_TYPE,TREE_STATE,TREE_DESC) VALUES (#{treeName},#{treeAge},#{treeHight},#{treeType},#{treeState},#{treeDesc}) ")    int addTree(Tree tree);    
    // 此处treeState是一个枚举，此处执行一直报错
    @Update("UPDATE TREE SET TREE_STATE=#{treeState} WHERe TREE_ID=#{treeId}")    int updateState(final int treeId, final TreeState treeState);    
    @Delete("DELETE FROM TREE WHERe TREE_ID=#{treeId}")    int deleteTree(final int treeId);    
    @Results({            @Result(id = true, column = "TREE_ID",property = "treeId"),            @Result(column = "TREE_NAME",property = "treeName"),            @Result(column = "TREE_AGE", property = "treeAge"),            @Result(column = "TREE_HIGHT",property = "treeHight"),            @Result(column = "TREE_TYPE",property = "treeType",typeHandler = EnumOrdinalTypeHandler.class),            @Result(column = "TREE_STATE",property = "treeState",typeHandler = EnumOrdinalTypeHandler.class),            @Result(column = "TREE_DESC", property = "treeDesc")
    })    @Select("SELECT * FROM TREE WHERe TREE_ID=#{treeId}")    Tree getTree(final int treeId);    
    @Results({            @Result(id = true, column = "TREE_ID",property = "treeId"),            @Result(column = "TREE_NAME",property = "treeName"),            @Result(column = "TREE_AGE", property = "treeAge"),            @Result(column = "TREE_HIGHT",property = "treeHight"),            @Result(column = "TREE_TYPE",property = "treeType",typeHandler = EnumOrdinalTypeHandler.class),            @Result(column = "TREE_STATE",property = "treeState",typeHandler = EnumOrdinalTypeHandler.class),            @Result(column = "TREE_DESC", property = "treeDesc")
    })    @Select("SELECT * FROM TREE")    List getTrees(RowBounds rowBounds);
}

注意：重点就在这个接口中，我们添加接口注解@Mapper，表示这是一个持久层Mapper,它的实例化依靠SpringBoot自动配置完成。
在接口方法上直接添加对应的执行注解，在注解中直接定义SQL，这种SQL仍然可以使用表达式#{}来获取参数的值。
注意@Result注解中定义的两个关于枚举的类型处理器EnumOrdinalTypeHandler，其实其为MyBatis内部自带的两种枚举处理器之一，
用于存储枚举序号，还有一个EnumTypeHandler用于存储枚举名称。

@Service@Log4j2public class TreeService {    
    @Autowired
    private TreeRepository treeRepository;    
    public ResponseEntity addTree(final Tree tree){
        treeRepository.addTree(tree);        return ResponseEntity.ok(tree);
    }    
    public ResponseEntity updateTree(final int treeId, final TreeState treeState){
        treeRepository.updateState(treeId,treeState);        return ResponseEntity.ok(Tree.builder().treeId(treeId).treeState(treeState).build());
    }    
    public ResponseEntity deleteTree(final int treeId){        return ResponseEntity.ok(treeRepository.deleteTree(treeId));
    }    
    public ResponseEntity getTree(final int treeId){        return ResponseEntity.ok(treeRepository.getTree(treeId));
    }   
    public ResponseEntity> getTrees(final int pageId,final int pageSize){
        List trees = treeRepository.getTrees(new RowBounds(pageId,pageSize));
        MyPage treeMyPage = new MyPage<>();
        treeMyPage.setPageId(pageId);
        treeMyPage.setPageSize(pageSize);
        treeMyPage.setBody(trees);        return ResponseEntity.ok(treeMyPage);
    }
}

@RestController@RequestMapping("/tree")@Api(description = "树木接口")public class TreeApi {   
    @Autowired
    private TreeService treeService;    
    @RequestMapping(value = "/addTree",method = RequestMethod.PUT)    @ApiOperation(value = "添加树木",notes = "添加新树木",httpMethod = "PUT")    public ResponseEntity addTree(final Tree tree){        return treeService.addTree(tree);
    }    
    @RequestMapping(value = "/updateTree",method = RequestMethod.POST)    @ApiOperation(value = "更新状态",notes = "修改树木状态",httpMethod = "POST")    public ResponseEntity updateTree(final int treeId,final TreeState treeState){        return treeService.updateTree(treeId,treeState);
    }    
    @ApiOperation(value = "获取树木",notes = "根据ID获取一棵树",httpMethod = "GET")    @RequestMapping(value = "/getTree",method = RequestMethod.GET)    public ResponseEntity getTree(final int treeId){        return treeService.getTree(treeId);
    }
}

注意：这个例子中更新状态的时候还是无法成功，这个状态是枚举值