构造函数参数的优化

Question

我将参数直接设置到 DTO 中，我们从 HQL 获得输出

以下是 HQL：

@Query(value = "SELECT new com.test.vos.CustomerDetails(firstname, lastName, address1, address2, address3, id, companyName, companyAddress, otherDetails) "
            + "FROM MstCustomer mc "
            + "INNER JOIN mc.mstAddress md "
            + "INNER JOIN mc.MstCompany mComapny "
            + "WHERE mc.mobileNo = :mobileNo ")
public List<CustomerDetails> getCustomerDetails(@Param("mobileNo") Integer mobileNo);

DTO：

public class CustomerDetails {
    private String firstName;
    private String lastName;
    private String address1;
    private String address2;
    private String address3;
    private String id;
    private String companyName;
    private String companyAddress;
    privatr String otherDetails;

    public CustomerDetails(String firstName, String lastName, String address1, String address2, String address3, String id, String companyName, String companyAddress, String otherDetails) {
        super();
        this.firstName = storeCode;
        this.lastName = lastName;
        this.address1 = address1;
        this.address2 = address2;
        this.address3 = address3;
        this.id = id;
        this.companyName = companyName;
        this.companyAddress = companyAddress;
        this.otherDetails = otherDetails;
    }

    // Getter and Setter
}

以上所有代码都可以正常工作，唯一的问题是它的显示 构造函数有9个参数，大于7个授权。

如何解决该警告？最好的方法是什么？

Answer 1

使用Builder pattern 在构造函数中获取一个参数（构建器）

 private CustomerDetails(CustomerDetailsBuilder builder) {
    // ... set all fields using builder
 public static class CustomerDetailsBuilder
    //...update all parameters and build method

这使用了一个额外的 UserBuilder 类，它可以帮助我们构建所需的 User 对象，其中包含所有必需属性和可选属性的组合，而不会失去不变性。

例如

CustomerDetails customerDetails = new CustomerDetails.CustomerDetailsBuilder("Lokesh", "Gupta")
.address1("street 1")
.address2("Floor 2")
.address3("Fake address 1234")
.build();

另一种选择是龙目岛的@AllArgsConstructor

生成一个全参数的构造函数。全参数构造函数要求类中的每个字段都有一个参数。