Thread: How do I set an Entity to read in another Entity which has a List<String> in Servlet?

I have 2 entities - tutor and Subject.

At the controller, I have problem with the code where I need to set the tutor to get the list of subjects which are in String.

Here's the snippet of code in the servlet:

tutor m4 = new tutor();

String[] subj = request.getParameterValues("subject");

List<string>subjects = new ArrayList<string>(Arrays.asList(subj));

for(String subject : subjects){ //next() returned showed values
System.out.println(subject);//no explicit return value
// m4.setSubject(subject); //setSubject() returned null
//m4.setSubjlist(subjects);
m4.setSubjs((Subject) subjects);

I have tried various ways to set the subject at the class without avail.

The error message // shows that the tutor is not reading in the values



Here's how I did the setter at tutor class



public class tutor{
private String tutorName;
tutor subj;
public tutor setSubject(String subject) {
return this.subj;
}


My question is how do I write the setter in tutor Class in order for the code to work in the Servlet.

Can this be done using pure Java at all? I heard there is this so called dependency injection but I am not sure how to make use of it in my case. Hope someone can also shed some light on this. Tks.

I am using Java EE7 and jdbc, 1.8 Java SE and Tomcat.

Originally Posted by jim829

Not certain what you're trying to do but here is how setters and getters work.

public class Demo {
    private String value;
 
    public void setValue(String val) {
        value = val;
    }
 
    public String getValue() {
        return value;
    }
}

Regards,
Jim

I think you have never done servlet or many to many using pure Java and JDBC so it will be difficult for you to understand about my problem.

Your above code is only good for normal single table where I have no problem in doing the getter and setter.