从arraylist java获取值？

Question

I have the following class

   public class Patient implements Serializable {

  private int id;

  private String name;

  private String desc;
    public Patient(int id, String name, String desc) {

    this.id = id;
    this.name = name;
    this.desc=desc;
    }

And then the following getter and setter methods in this class.

Declaring the arraylist

  ArrayList<Patient> list = new ArrayList<Patient>();

Adding run time data in the list

   list.add(new Patient(id++, name.getText(), disDesc.getText())

Now i want the read the elements stored in the list How can i do that?

    System.out.println(list.get(0));

I use this but it returns the object address of the class

Answer 1

You have to override the toString() method of Patient . There, you will return all information on the Patient object that you want to display.

(my personal favorite)

 private static final String SEPARATOR = ", ";

 @Override
 public String toString()
 {
      StringBuilder builder = new StringBuilder();

      builder.append("ID: ").append(id).append(SEPARATOR);
      builder.append("Name: ").append(name).append(SEPARATOR);
      builder.append("Desc: ").append(desc);

      return builder.toString();
 }

 @Override
 public String toString()
 {
      return "ID: " + id + ", Name: " + name + ", Desc: " + desc;
 }

 @Override
 public String toString()
 {
      return MessageFormat.format("ID: {0}, Name: {1}, Desc: {2}", id, name, desc);
 }

Use either one. It is a matter of preference.

Answer 2

You have to cast the element,

((Patient) list.get(0)).getName();

And you must add a public getter method to your Patient class.