Java - 无法为最终变量查询赋值。 它是最终的String

Question

I have a problem with final string. It is a mysql database client. I want to change query with clicking JButton.

public void run() {
final String query;
(...)
start.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e)
    {
if(firstSel==null || selchose.getText().equals(selchose_str) || selbase.getText().equals(base_str)) {
            query = "Select * FROM EMP";
        }
(...)

The problem is with

query = "Select * FROM EMP";

It shows me

cannot assign a value to final variable query

How to solve the problem?

Answer 1

使查询String成为私有类字段或匿名内部ActionListener类的本地变量。

Answer 2

class YOurClassName{

private String query; //make here.....<<<<<<<<

public void run() {

(...)
start.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e)
    {
if(firstSel==null || selchose.getText().equals(selchose_str) || selbase.getText().equals(base_str)) {
            query = "Select * FROM EMP";
        }
(...)


}