Mapstruct使用笔记

Posted 2020-10-23 商商-77

Mapstruct 可以用来处理java实体间的转换，比如DTO转DO，DO转DTO。

Pom依赖如下

<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct</artifactId>
    <version>1.2.0.Final</version>
</dependency>
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct-processor</artifactId>
    <version>1.2.0.Final</version>
    <scope>provided</scope>
</dependency>

public class BooleanIntegerMapper {
    public int asInt(boolean success) {
        return success ? 1 : 0;
    }

    public boolean asBoolean(int success) {
        return success == 1;
    }
}

@Mapper(uses = { BooleanIntegerMapper.class })
public interface FaultyMachineMapper {

    FaultyMachine doToDTO(FaultyMachineDO FaultyMachineDO);

    CloudboxFaultyMachineDO dtoToDO(FaultyMachine faultyMachine);

    List<FaultyMachine> dosToDTOs(Iterable<FaultyMachineDO> faultyMachineDOS);
}

Mapstruct会为FaultyMachineMapper生成实现类FaultyMachineMapperImpl，在工程的target目录下可以看到。Spring初始化时会实例化FaultyMachineMapperImpl对象，并且注入到需要使用的地方。

代码中的使用

public class FaultyMachineRepositoryImpl implements FaultyMachineRepository {

    private FaultyMachineMapper faultyMachineMapper = Mappers.getMapper(FaultyMachineMapper.class);

    @Setter
    private FaultyMachineDAO faultyMachineDAO;

    @Override
    public FaultyMachine getById(int id) {
        FaultyMachineDO faultyMachineDO = faultyMachineDAO.getById(id);
        FaultyMachine faultyMachine = faultyMachineMapper.doToDTO(faultyMachineDO);
        return faultyMachine;
    }

    @Override
    public int insertFaultyMachine(FaultyMachine faultyMachine) {
        FaultyMachineDO faultyMachineDO = faultyMachineMapper.dtoToDO(faultyMachine);
        return (int)faultyMachineDAO.insertFaultyMachine(faultyMachineDO);
    }
}

如果Java类中有一个字段是boolean类型的，对应DB中类型是tinyint，此时使用BeanUtil在DTO和DO之间copy时会报错提示参数类型不匹配。

使用以上的方式就不存在这个问题。