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java - 为什么我会得到，我该如何解决这个“字符串到对象类型“ 错误

问题描述

我（作为一个绝对的初学者）正在尝试创建一个简单的工具，它可以创建一些对象并将它们链接起来。对象是：客户许可证（2 种类型，扩展类）

这个想法是在创建许可证时使用（其中一个）客户公司名称，因此许可证链接到客户。我使用 ArrayLists 来存储数据。

我尝试为客户 cCompany 使用 getter，但是当我尝试实际创建新的许可证对象时，我收到有关不兼容类型的错误（字符串到客户类型的对象）

我该如何解决这个错误？

任何帮助都非常感谢，但请解释清楚，我是一个绝对的初学者。我可能过于复杂的东西......

一些代码摘录：

从主要：

public class Main {

    public static void main(String[] args) {
        //Create customers
        List <Customer> customers = new ArrayList <> (10);
        customers.add(new Customer("TestCompany","John Doe",1234567890,"John@testcompany.com"));


....

//Create Elvis licenses (based on superclass License)
List <ElvisLicense> ellicenses = new ArrayList <> (10);
ellicenses.add(new ElvisLicense("TestCompany","VendorA",1234,"1234-A","Solutions Server gold","1234-dtbk-87654-nlof",10, true , true));

类别： 客户：

class Customer {
    String cCompany;
    private String cName;
    private int cPhone;
    private String cEmail;

    public Customer( String cCompany, String cName,int cPhone, String cEmail)
    {
    this.cCompany = cCompany;
    this.cName = cName;
    this.cPhone = cPhone;
    this.cEmail = cEmail;
    }

    //This getter should be used to link the license to the customer (Done in License.java)
    public String getcCompany() {
        return cCompany;
    }

类许可证（超类）

class License {
// Used no modifier to set access for Class/Package and Subclass inside the package
Customer licenseCompany;
String lVendor;
int lContractNumber;
String lCertificateNumber;
String lProductName;
String lLicenseKey;
int lNumberOfSeats;


    public License(Customer cCompany, String lVendor, int lContractNumber, String lCertificateNumber, 
            String lProductName, String lLicenseKey, int lNumberOfSeats)
    {
    licenseCompany = cCompany;
    this.lVendor = lVendor;
    this.lVendor = lVendor;
    this.lContractNumber = lContractNumber;
    this.lCertificateNumber = lCertificateNumber;
    this.lProductName = lProductName;
    this.lLicenseKey = lLicenseKey;
    this.lNumberOfSeats = lNumberOfSeats;    
    }


    public Customer getLicenseCompany() {
        return licenseCompany;
    }

    public void setLicenseCompany(Customer licenseCompany) {
        this.licenseCompany = licenseCompany;
    }


//preparations to allow for example printing the content of an arraylist element
    @Override
    public String toString(){
    return "Customer name " + getLicenseCompany()  + "\n" + "Vendor name " + getlVendor()  + "\n" + "Contract number: " + getlContractNumber() + "\n"
               + "Certificate number: " + getlCertificateNumber() + "\n" + 
                "Product name " + getlProductName()  + "\n" + "Licence key: " + getlLicenseKey() + "\n"
               + "Number of seats: " + getlNumberOfSeats();
}


}

和扩展类：

public class ElvisLicense extends License{

private boolean elIsBundle;
private boolean elIsSubscription;


public ElvisLicense(
        Customer licenseCompany,
        String lVendor,
        int lContractNumber,
        String lCertificateNumber, 
        String lProductName,
        String lLicenseKey,
        int lNumberOfSeats,
        boolean elIsBundle,
        boolean elIsSubscription
        )

    {
    super(
            licenseCompany,
            lVendor,
            lContractNumber,
            lCertificateNumber,
            lProductName,
            lLicenseKey,
            lNumberOfSeats);

    this.elIsBundle = elIsBundle;
    this.elIsSubscription = elIsSubscription;
    }  


.....



@Override
public String toString(){
    return "Customer name " + licenseCompany  + "\n" 
            + "Vendor name " + lVendor  + "\n" 
            + "Contract number: " + lContractNumber + "\n"
            + "Certificate number: " + lCertificateNumber + "\n" 
            + "Product name " + lProductName  + "\n" 
            + "Licence key: " + lLicenseKey + "\n"
            + "Number of seats: " + lNumberOfSeats + "\n"
            + "Number of seats: " + elIsBundle + "\n" 
            + "Number of seats: " + elIsSubscription;
}

}

我希望在创建新许可证时使用客户名称。

标签： javastringobjectarraylist

解决方案

下面的行是错误的。

ellicenses.add(new ElvisLicense("TestCompany","VendorA",1234,"1234-A","Solutions Server gold","1234-dtbk-87654-nlof",10, true , true));

作为许可证需要客户对象一个参数。相反，您应该首先创建客户对象。

ellicenses.add(new ElvisLicense(new Customer("TestCompany","VendorA",1234,"1234-A"),"Solutions Server gold","1234-dtbk-87654-nlof",10, true , true));

重复使用它customer list以避免创建公司。

for(Customer customer : customers){
   // here you need some way to offer other parameters except customer parameter.
   License license = new new ElvisLicense(customer,"Solutions Server gold","1234-dtbk-87654-nlof",10, true , true);
   ellicenses.add(license);
}

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