求解: setText() 无法更新公用JTextField的问题！

weixin_46017755 2020-12-02 10:27:15

录入数据的输入框与点击右侧集合列表向输入框显示具体信息是共用的，
录入信息好使，点击列表就更新输入框了，
明明构造方法传入了值，print也输出了，可是setText()就是不运行

这是成功录入数据，生成右侧的列表

当点击右侧列表时，左侧输入框不刷新

这个判定确定的清空 setText()就好使



       //点击确定按钮

            if(e.getSource() == button7){

                if(flagAge && flagClass && flagID && flagName && flagSex){

                    sta.executeUpdate(into);

                    JOptionPane.showMessageDialog(null, "添加成功！");

                    //清空 输入框

                    stuName.setText("");

                    stuAge.setText("");

                    stuClass.setText("");

                    stuID.setText("");

                    stuSex.setText("");

                    //文本域显示命令

                    tamlh.setText(""); //清空

                    tamlh.append(beginTime + "执行成功: " + into + "\n");

                    //向集合框里添加列表项

                    stuList.add(IDText + "," + nameText);

                } else {

                    sta.executeUpdate(update); //删除空值

                    JOptionPane.showMessageDialog(null, "你的输入不合法！");

                    tamlh.setText(""); //清空

                    tamlh.append(beginTime + ": 请输入完整的学生信息！\n");

                }

            }

下面贴源码这个注册了监听器 stuList.addActionListener(new ListListener()); //调用类 : 列表项的点击方法列表的点击
看百度说什么线程问题，但是我自己写了个线程 setText()也不运行啊



    String nameList = null;

    String stuClassList = null;

    String IDList = null;

    String sexList = null;

    String ageList = null;

    //构造函数 传递List List内查询的值 赋给 输入框

    public void stuText(String nameList, String stuClassList, String IDList, String sexList, String ageList) {

        newf Listrun = new newf();

        this.nameList = nameList;

        this.stuClassList = stuClassList;

        this.IDList = IDList;

        this.sexList = sexList;

        this.ageList = ageList;

        Thread th = new Thread(Listrun);

        th.start();

        System.out.println("运行了" + nameList + stuClassList + IDList + sexList + ageList);

    }

    @Override

    public void run() {

        stuName.setText(nameList);

        stuAge.setText(stuClassList);

        stuClass.setText(IDList);

        stuID.setText(sexList);

        stuSex.setText(ageList);

        System.out.println("运行了111111" + nameList + stuClassList + IDList + sexList + ageList);

    }

这个时调用的类



package DaZuoYe;



import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

import java.sql.*;

import java.util.Arrays;



class ListListener implements ActionListener,ItemListener{



    String nameList = null;

    String stuClassList = null;

    String IDList = null;

    String sexList = null;

    String ageList = null;



    @Override

    public void itemStateChanged(ItemEvent e) {

        // TODO Auto-generated method stub

        //System.out.println(e.getSource());

    }



    @Override

    public void actionPerformed(ActionEvent e) {

        // TODO Auto-generated method stub

        //System.out.println(e.getActionCommand());



        String str =  e.getActionCommand();

        String[] arr = str.split(","); // 用,分割

        System.out.println(Arrays.toString(arr));



        try {

            Class.forName("com.mysql.cj.jdbc.Driver");  //加载驱动程序

            Connection conn = DriverManager.getConnection(  //链接数据库

                    "jdbc:mysql://112.125.95.197:3306/java",

                    "java", "Aa316216");//建立数据库连接

            Statement sta = conn.createStatement();  //用sta执行SQL语句





            String select = "select * from stu where name = '"+ arr[1] +

                    "' and ID = '"+ arr[0] +"';";

            System.out.println(arr[0] + arr[1]);



            ResultSet rs = sta.executeQuery(select);



            while (rs.next()){

                nameList = rs.getString(1);

                stuClassList = rs.getString(2);

                IDList = rs.getString(3);

                sexList = rs.getString(4);

                ageList = rs.getString(5);

            }

            System.out.println(nameList + stuClassList + IDList + sexList + ageList);



           new newf().stuText(nameList,stuClassList,IDList,sexList,ageList);





        } catch (ClassNotFoundException classNotFoundException) {

            classNotFoundException.printStackTrace();

        } catch (SQLException throwables) {

            throwables.printStackTrace();

        }

    }



}