使用另一个类中的jbutton动作将jcombobox变量从一个类传递到另一个类

Question

So, in Java I have two classes is created using swing components . In one class, named SearchPage , I set up parameters for a search in the Jtextfield or Jcombobox provided and click the apply jbutton . When I do that, depending on what field contains data, I want to send that variable over to the ItemPage class to be used in my pop_tree method to use that variable to search my mysql database and populate the tree with the search results. How can I accomplish this?

Here is the code for the pop_tree method:

public final void pop_tree() throws SQLException {
    //creating root node
    DefaultTreeModel dbtree = (DefaultTreeModel)DBTree.getModel();
    dbtree.reload();
    dbtree.getRoot();
    DefaultMutableTreeNode content = new DefaultMutableTreeNode("Content");

        //let's see if I can create these child nodes
        SearchPage s = new SearchPage();
        try {
            con = DBconnect.getConnection();
            stm = con.createStatement();
            s.apply_search_button.doClick();
            if(s.apply_search_button.getModel().isPressed()){
            //Grab what's in search field of Search Page
            try{
                String search = s.search_field.getText();
                if (search == null){
                    return;
                }else{
                    ResultSet rs = stm.executeQuery("SELECT * from displaydetails WHERE item LIKE '%"+search+"%'");
                    while (rs.next()){
                        DefaultMutableTreeNode itemNode = new DefaultMutableTreeNode (rs.getString("item"));
                        content.add(itemNode);
                    }
                }
            }catch(SQLException e){
                System.out.println(e);
            }

            try{
                //If a genre selection is made in the combo box:
                if ((s.option_box.getSelectedItem())== "genre"){
                String genre2 = s.result_box.getSelectedItem().toString();
                if (genre2.equals(s.result_box.getSelectedItem())) {
                    ResultSet rs1 = stm.executeQuery("SELECT * from displaydetails WHERE genre = '" + genre2 + "';");
                    while (rs1.next()){
                        DefaultMutableTreeNode itemNode = new DefaultMutableTreeNode (rs1.getString("item"));
                        content.add(itemNode);
                    }
                }
            }
            }catch(SQLException e){
                System.out.println(e);
            }

I have the search form created to setup the search parameters, but when I click the apply_search_button on the form, I want to send the variable to the proper location in the pop_tree() method to perform the search. Can anyone help me with this? Thanks.

Answer 1

To get answer to "Passing a jcombobox variable from one class to another class using a jbutton action in another class" much of the code posted, is not needed. Always consider posting [mcve] .
Here is one that demonstrates just that :

import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;

public class SearchPage extends JFrame {

    private JTextField searchField;
    private JButton searchButton;
    private ItemPage itemPage;

    SearchPage(){
        setSize(200,100);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        searchField = new JTextField(9);
        add(searchField, BorderLayout.NORTH);

        searchButton = new JButton("Search");
        searchButton.addActionListener(e -> {

            String searchFor = searchField.getText();
            if ((searchFor != null) && ! searchFor.isEmpty()) {
                itemPage.search(searchFor);
            }
        });
        add(searchButton, BorderLayout.SOUTH);
        itemPage = new ItemPage();
        setVisible(true);
    }

    public static void main(String[] args)  {
        new SearchPage();
    }
}

class ItemPage {

    public void search(String searchFor) {
        System.out.println("Searching for "+ searchFor);
    }
}