Dynamically pass domain name into an a href link in Spring Jpa

I am trying to create a dynamic link in an email which am sending out using Spring Jpa. I created a variable in my application.properties file so that whenever I am pushing to server I can easily change that variable from localhost to the domain name for live deployment. However, when I try to pass the domain name value, the link becomes inactive. I would appreciate if you could point me in the right direction.

Here is the application.properties snippet below:

server.port=8008

spring.jpa.database=POSTGRESQL
spring.datasource.platform=postgres

spring.datasource.url=jdbc:postgresql://41.207.248.189:xxxx/xxx
spring.datasource.username=****
spring.datasource.password=****

##GMAIL PROPERTIES
senderEmail = xxxxx
spring.mail.host=xxxx
spring.mail.port=xxx
spring.mail.username=xxxxxx
spring.mail.password=xxxxxxx
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.ssl.trust=xxxxxxx

domain-name=localhost:4200

spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

Here is the snippet for the a href I need to pass the domain-name into:

 "\n" +

 "<a href='{domain-name}/payments/"+hashlink+"' target='_blank'>Click Here</a>"+                       

"\n" +

This approach above is not working but when I pass the link manually, the "click here" link works:

  "<a href='http://127.0.0.1:4200/payments/"+hashlink+"' target='_blank'>Click Here</a>"+   

I would appreciate your help. Thanks

UPDATE

Below is the html for the email body where I am setting the domain-name

            try {
                emailService.sendEmail("PAYMENT NOTIFICATION",

                        "<p>Dear sir/ma,</p>\n" +
                                "\n" +
                                "\n" +
                                "<h4>LETTER OF NOTICE </h4>\n" +
                                "\n" +
                                "\n" +
                                "<p>This is to notify you of the status of your organisation ..... </p>\n" +
                                "<p>You are hereby put on notice to remit the outstanding amount on or before ....</p>\n" +
                                "<p>Kindly follow the link below to make....\n</p>\n" +
                                "\n" +
                                "<a href='{domain-name}/payments/"+hashlink+"' target='_blank'>Click Here</a>"+  
                                "\n" +
                                "\n" +
                                "<p>Thank you.</p> \n" +
                                "\n"
                        , org.getEmail());
            } catch (
                    MessagingException e) {
                e.printStackTrace();
            } catch (Exception e) {
                System.out.println("Email Service error");
                e.printStackTrace();
            }
        }

I hope this helps... I look forward to getting a solution. Thanks.

Based on the comments/discussion here's what you need to do:

1. Read/Inject the property to a String variable using @Value
   
@Value("${domain-name}")
String domainName;


2. Use the variable to construct your href

Full code:

application.properties

domain-name=www.abc.com

DomainNameApp:

package domainname;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.*;

@SpringBootApplication
public class DomainNameApp {
    public static void main(String[] args) {
        SpringApplication.run(DomainNameApp.class, args);
    }
}

@RestController
class Ctrl {

    @Value("${domain-name}")
    String domainName; // or use constructor injection

    @GetMapping("a")
    void a() {
        String hashlink = "jsdklfsdklflsdf";
        String html = "<p>" +
                "<a href='" + domainName + "/payments/" + hashlink + "' target='_blank'>Click Here</a>" +
                "</p>";
        System.out.println(html);
    }

}

</details>



# 答案2
**得分**: 1

基于@gtiwari333的回答... 我对我的代码进行了一些更正。我决定详细说明我为将来的读者所做的更改。

首先，我在我的`application.properties`文件中添加了`http://`参数，如下所示：

domain-name=http://localhost:4200

接下来，我在我的类顶部添加了`@Value`注解，如下所示：

@Value("${domain-name}")
String domainName;

然后，我能够轻松地将它传递给链接中的`a href`，如下所示：

"

请点击下面的链接进行....\n

\n" +
"\n" +
"点击这里" +
"\n" +
"\n" +
"

谢谢。

\n" +
"\n"

感谢。我要感谢@gtiwari333帮助我完成这个。

<details>
<summary>英文:</summary>

Based on answers by @gtiwari333...  I made some corrections to my code. I decided to detail the changes I made for future readers. 


First of all, I added http:// to the parameter in my application.properties, as below:

domain-name=http://localhost:4200

next, I added @Value annotation to the top of my class as below:

@Value("${domain-name}")
String domainName;

Then I was able to pass it into the a href link with ease as below:

"<p>Kindly follow the link below to make....\n</p>\n" +
"\n" +
"<a href='" +domainName+ "/payments/payment-make" + link + "' target='_blank'>Click Here</a>" +
"\n" +
"\n" +
"<p>Thank you.</p> \n" +
"\n"

Thanks. I give credit to @gtiwari333 for helping me with this.

</details>