How to iterate an object over a list of objects in JSTL?

问题

I have a class named Language with 1 field named name. I have another class named Speech which has a language member. I need to iterate over a list of Speech objects. In JSTL:

<c:forEach items="${requestScope.Speech}" var="speech">
  <tr>
    <td>&nbsp;${speech.id}</td>
    <td>&nbsp;${speech.language.name}</td>
  </tr> 
</c:forEach>

My second statement ${speech.language.name} doesn't work. How can I make it work?

Speech and Language classes:

public class Speech {
    private int id;
    private Language language=null;

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public Language getLanguage() {
        return language;
    }
    public void setLanguage(Language language) {
        this.language = language;
    }
}

public class Language {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    } 
}

回答1:

Make sure that your Speech class has a public Language getLanguage() method defined.

回答2:

The JSP EL doesn't use fields. It uses properties. In order for this statement to work, you need to have a public method getLanguage() in Speech, and a public method getName() in Language.

EDIT:

If the getters are there, and nothing is being printed, it can have four reasons:

there is no Speech attribute in the request
there is a list of Speeches in the Speech request attribute, but this list is empty
the language of each Speech of the list is null
the name of each Language is null or blank.

If something is printed for the speech ID, it eliminates the first two reasons.

来源：https://stackoverflow.com/questions/8711251/how-to-iterate-an-object-over-a-list-of-objects-in-jstl

标签

java

jstl