无法在JTree中右键显示叶节点的名称

Question

我正在为我的学校做练习，我需要使用Jtree并在JList中显示内容，当我显示我的树时，叶子有这些奇怪的名字pruebaswing.Schedule@2037c981或pruebaswing.Schedule@7b052786，和我不知道为什么，我使用这个Java的例子＃34;如何使用树＆＃34;来帮助我做树：

http://docs.oracle.com/javase/tutorial/displayCode.html?code=http://docs.oracle.com/javase/tutorial/uiswing/examples/components/TreeDemoProject/src/components/TreeDemo.java

//This is when i create the leaf

    faculty= new DefaultMutableTreeNode(faculties[i]); //i create a new node father
            if  (i==0){

                top.add(faculty); //the father adds to the root ("top") of the tree

                for (int j = 0; j < degrees.length; j++) { 
                //the cycle for add the leaf in to the tree top

                    carrer= new DefaultMutableTreeNode(new Schedule(degrees[j])); //this is when i create the leaf with a specific content of new object like the example of java

                    facultad.add(carrer); //this when i add the leaf on the tree

                }
            }

//This is the class of the object Schedule

    public class Schedule{

        public String carrer_name; //The name of the leaf that not displayed
        DefaultListModel classes;  //The List of classes


        public Schedule(String degree){

            carrer_name=degree;

            String Ing_Civil[]={"Ladrillos", "Puentes", "Hidraulica"};
            classes = new DefaultListModel();

            if(degree=="Ingenieria Civil"){
                for (int i = 0; i < Ing_Civil.length; i++) {
                    classes.addElement(Ing_Civil[i]);
                }
            }
     }

抱歉我的英文