Spring存储库自定义查询Spel计算始终为空

每次在我的存储库中调用findByFirstNameContainingOrLastNameContaining函数时，我都会收到以下错误：

org.springframework.expression.spel.SpelEvaluationException: EL1007E:(pos 0): Property or field 'firstName' cannot be found on null

我的问题错了吗？我对这个错误一无所知

这是我的档案：

Person.java

package com.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Person {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    long id;

    String firstName;

    String lastName;

    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

PersonRepository.java

package com.repositories;

import com.model.Person;
import java.util.List;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;

public interface PersonRepository extends CrudRepository<Person, Long> {
    @Query("SELECT p FROM Person p WHERE p.firstName LIKE %:firstName% OR "
            + "p.firstName LIKE %:lastName% OR "
            + "p.lastName LIKE %:lastName% OR "
            + "p.lastName LIKE %:firstName%")
    public List<Person> findByFirstNameContainingOrLastNameContaining(
        @Param(value = "firstName") String firstName, 
        @Param(value = "lastName") String lastName
    );
}

package.com.repositories；
导入com.model.Person；
导入java.util.List；
导入org.springframework.data.jpa.repository.Query；
导入org.springframework.data.repository.crudepository；
导入org.springframework.data.repository.query.Param；
公共接口PersonRepository扩展了Crudepository{
@查询（“从人员p中选择p，其中p.firstName类似%：firstName%或”
+“p.firstName LIKE%：lastName%或”
+“p.lastName LIKE%：lastName%或”
+“p.lastName（如%：firstName%”）
公共列表FindByFirstNameContaining或LastNameContaining(
@Param（value=“firstName”）字符串firstName，
@参数（value=“lastName”）字符串lastName
);
}

将您的%xxx%替换为：{parameter}即可使用

package com.example.repository;

import com.example.model.Employee;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

import java.util.List;


public interface EmployeeRepository extends JpaRepository<Employee, Long> {

@Query("SELECT e FROM Employee e WHERE e.firstName LIKE :firstName OR "
    + "e.firstName LIKE :lastName OR "
    + "e.lastName LIKE :lastName OR "
    + "e.lastName LIKE :firstName")
List<Employee> findByFirstNameContainingOrLastNameContaining(
    @Param(value = "firstName") String firstName,
    @Param(value = "lastName") String lastName
);
}

package com.example.repository；
导入com.example.model.Employee；
导入org.springframework.data.jpa.repository.JpaRepository；
导入org.springframework.data.jpa.repository.Query；
导入org.springframework.data.repository.query.Param；
导入java.util.List；
公共接口EmployeeRepository扩展了JpaRepository{
@查询（“从员工e中选择e，其中e.firstName类似：firstName或”
+“例如：lastName或”
+“e.lastName类似于：lastName或”
+“e.lastName如：firstName”）
列出findByFirstNameContainingOrLastNameContaining(
@Param（value=“firstName”）字符串firstName，
@参数（value=“lastName”）字符串lastName
);
}