“世间事，除了生死，哪一件不是闲事。”——仓央嘉措《地空》。
分享一个lombok注解@RequiredArgsConstructor
同样和@AllArgsConstructor支持onConstructor参数
区别在于，@RequiredArgsConstructor只针对final的字段生成带参构造器
例如：
package com.ruben.simplescaffold.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.ruben.simplescaffold.entity.UserDetail; import com.ruben.simplescaffold.manager.JsonManager; import com.ruben.simplescaffold.mapper.UserDetailMapper; import com.ruben.simplescaffold.service.IUserDetailService; import lombok.RequiredArgsConstructor; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; /** * <p> * 服务实现类 * </p> * * @author <achao1441470436@gmail.com> * @since 2021/7/30 10:31 */ @Service @Transactional(rollbackFor = Exception.class) @RequiredArgsConstructor(onConstructor = @__(@Autowired)) public class UserDetailServiceImpl extends ServiceImpl<UserDetailMapper, UserDetail> implements IUserDetailService { private final JsonManager jsonManager; /** * 获取jsonManager * * @return jsonManager */ @Override public JsonManager getJsonManager() { return jsonManager; } }
生成后结果：
// // Source code recreated from a .class file by IntelliJ IDEA // (powered by FernFlower decompiler) // package com.ruben.simplescaffold.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.ruben.simplescaffold.entity.UserDetail; import com.ruben.simplescaffold.manager.JsonManager; import com.ruben.simplescaffold.mapper.UserDetailMapper; import com.ruben.simplescaffold.service.IUserDetailService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; @Service @Transactional( rollbackFor = {Exception.class} ) public class UserDetailServiceImpl extends ServiceImpl<UserDetailMapper, UserDetail> implements IUserDetailService { private final JsonManager jsonManager; public JsonManager getJsonManager() { return this.jsonManager; } @Autowired public UserDetailServiceImpl(JsonManager jsonManager) { this.jsonManager = jsonManager; } }
如果有循环依赖，我们再加一个@Lazy即可
就像这样：
package com.ruben.simplescaffold.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.ruben.simplescaffold.entity.UserDetail; import com.ruben.simplescaffold.manager.JsonManager; import com.ruben.simplescaffold.mapper.UserDetailMapper; import com.ruben.simplescaffold.service.IUserDetailService; import lombok.RequiredArgsConstructor; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Lazy; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; /** * <p> * 服务实现类 * </p> * * @author <achao1441470436@gmail.com> * @since 2021/7/30 10:31 */ @Service @Transactional(rollbackFor = Exception.class) @RequiredArgsConstructor(onConstructor = @__({@Autowired,@Lazy})) public class UserDetailServiceImpl extends ServiceImpl<UserDetailMapper, UserDetail> implements IUserDetailService { private final JsonManager jsonManager; private final IUserDetailService userDetailService; /** * 获取jsonManager * * @return jsonManager */ @Override public JsonManager getJsonManager() { return jsonManager; } }
实际：
// // Source code recreated from a .class file by IntelliJ IDEA // (powered by FernFlower decompiler) // package com.ruben.simplescaffold.service.impl; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.ruben.simplescaffold.entity.UserDetail; import com.ruben.simplescaffold.manager.JsonManager; import com.ruben.simplescaffold.mapper.UserDetailMapper; import com.ruben.simplescaffold.service.IUserDetailService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Lazy; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; @Service @Transactional( rollbackFor = {Exception.class} ) public class UserDetailServiceImpl extends ServiceImpl<UserDetailMapper, UserDetail> implements IUserDetailService { private final JsonManager jsonManager; private final IUserDetailService userDetailService; public JsonManager getJsonManager() { return this.jsonManager; } @Autowired @Lazy public UserDetailServiceImpl(JsonManager jsonManager, IUserDetailService userDetailService) { this.jsonManager = jsonManager; this.userDetailService = userDetailService; } }
