将变量及其值添加到Java GUI

Question

I want to add to a Java JFrame a list of my class's fields names, along with their respective values. Those fields can of course change value during the program's execution and i want this change to be displayed dynamically in my GUI. If for example i have a field private int networkId; in a class BaseStation , how can i make it appear in the frame of a class BaseStationFrame ?

Answer 1

我不是100％理解这个问题，但是如果通过JavaBeans， l2fprod PropertySheet会做你需要的吗？

Answer 2

A common approach would be to access the methods from the component that allow you to manipulate the component values.

Here a simple example using a text area.

private final static String newline = "\n";
private JTextArea textArea;


public void init() {
   //Make sure your components are not null;
   textArea = new JTextArea();  
}   

public void actionPerformed(ActionEvent evt) {
    String text = textArea.getText();
    textArea.append(textArea + newline);
}

//Get set methods

Depending on your needs and variable type, you might need to parse or use special methods. I would recomend you to read the documentation for the javax.swing package.

Also in oracles site there is a great tutorial on javax.swing GUI

Answer 3

Well...you could store static final Strings that contain the names of your fields, and design some association between the String representation of the name of a field, and the value of that field.

Or, you could use a Map for all of your fields, defining key-value pairs for them. When you want to call the fields, you do a Map.get(), and when you want to print them, you could do something like

Set s = map.keySet()
for(Object o : s) {
    print(o.toString() + " = " + map.get(o).toString())
}

This is, of course, Sudocode to hopefully get the ball rolling for you

Good Luck :)

Answer 4

If you want your UI to have access to private fields of your class, you won't have much options

• Use reflection to access those fields (not recommended)
• Make those fields public (not recommended either) or package visible and place all code in one package (not recommended either)
• Add decent getters and setters and fire PropertyChangeEvent s when those fields change.

Your UI can then use the getter to obtain the initial value, and use the events to update the UI when the value of a field has been changed. You could even write a fairly generic UI component for this by using reflection to obtain all the getters, but if it is only for a few classes this might be overkill