小编hkn*_*z47的帖子

Incompatible types. Required: ...model.Constants Found: java.util.Optionaljpa 方法上有红色下划线并带有消息：\n findById。

我用findById is here:

Constants constants=constantsRepository.findById(1L);\n

我的模型是：

@Id\n@GeneratedValue(strategy = GenerationType.IDENTITY)\n@Column(name = "pkid")\nprivate Long id;\n\npublic Long getId() {\n    return id;\n}\n\npublic void setId(Long id) {\n    this.id = id;\n}\n

有什么帮助吗？

这是我的所有代码

常量存储库接口

package com.destek.salaryCalculation.repository;\n\nimport com.destek.salaryCalculation.model.Constants;\nimport org.springframework.data.jpa.repository.JpaRepository;\nimport org.springframework.stereotype.Repository;\n\n@Repository\npublic interface ConstantsRepository extends  JpaRepository<Constants, Long>{\n\n}\n

BesCreateController java

package com.destek.salaryCalculation.controller;\n\nimport com.destek.salaryCalculation.helper.BesCreateExcelHelper;\nimport com.destek.salaryCalculation.model.Personal;\nimport com.destek.salaryCalculation.repository.PersonalRepository;\nimport org.apache.poi.openxml4j.exceptions.InvalidFormatException;\nimport org.springframework.beans.factory.annotation.Autowired;\nimport org.springframework.web.bind.annotation.*;\nimport javax.servlet.http.HttpServletResponse;\nimport java.io.IOException;\nimport java.util.List;\n\n@RestController\n@CrossOrigin(origins = "http://localhost:3000")\n@RequestMapping("/salarycalc")\npublic class BesCreateController {\n\n    @Autowired\n    private PersonalRepository …