Question

我想要做的是每当我使用特定ID登录时，它将根据键入的ID拉取学校名称。例如我在我的文件testing.txt中有这个并且我登录到0114343并且想验证如果学校是“通信学院”，它会将标签更改为“SOC”

这是我的代码到目前为止，但它不起作用它将只显示SOC，无论我登录的是哪个ID。感谢您的任何帮助。

LoginClass

public class TestingProgram {

JButton button1,button2;
JLabel label;
JTextField idField,passwdField;
BufferedWriter toFile;
BufferedReader validation;
String valuesArray[]={};
String idTitle;
int exists=0;
public TestingProgram()
{

    JFrame frame = new JFrame();   
    JPanel pnl = new JPanel();

    //Buttons
    button1 = new JButton("Add");
    button2 = new JButton("Login"); 

    //TextField
    idField = new JTextField(15);
    passwdField = new JTextField(15);

    pnl.add(button1);
    pnl.add(button2);
    pnl.add(idField);
    pnl.add(passwdField);


    button2.addActionListener((ActionEvent e )->{
       Validation();
    });

    frame.add(pnl,BorderLayout.NORTH);
    frame.setSize(500,500);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

   public String getIdTitle()
{
    idTitle = idField.getText();
    return idTitle;
}

public void Validation()
{
 try{
        validation = new BufferedReader(new FileReader("testing.txt"));
        String values=null;
        while((values = validation.readLine())!=null)
            {
                valuesArray = values.split(",");
                if(idField.getText().equals(valuesArray[0]) && passwdField.getText().equals(valuesArray[1]))
                {
                    exists = 1;
                    break;
                }                    
            }       
                 if(exists==1)
                {
                    SecondTest sec = new SecondTest();
                    sec.second();
                    sec.frame.setTitle(getIdTitle());
                }
                 else
                 {
                     System.out.println("Does not exsits in file");
                 }
        }

        catch(FileNotFoundException ex){
            ex.printStackTrace();
        }
        catch(IOException ex){
            ex.printStackTrace();
        }            

}

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

}

第二课

public class SecondTest 
{
JFrame frame;
JButton button;
JLabel label;
JPanel panel;
BufferedReader validation;
String valuesArray[] = {};
String school;
public void second()
{
    frame = new JFrame();
    button = new JButton("Button");
    label = new JLabel("");
    panel = new JPanel();
    panel.add(button);
    panel.add(label);

    try{
        validation = new BufferedReader(new FileReader("testing.txt"));
        String values=null;
        while((values=validation.readLine())!=null)
        {
            valuesArray=values.split(",");
            if(valuesArray[2].equals("SchoolofCommunication"))
            {
                school = "SOC";
                break;
            }
            else if(valuesArray[2].equals("SchoolofEngineering"))
            {
                school = "SOE";
                break;
            }         
        }
         if(school.equals("SOC"))
            {
                label.setText("SOC");
            }
            else 
            {
                label.setText("SOE");
            }


    }
        catch(FileNotFoundException ex){
            ex.printStackTrace();
        }
        catch(IOException ex){
            ex.printStackTrace();
        }     

    frame.add(panel,BorderLayout.CENTER);
    frame.setSize(450,450);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

Answer 1

second()没有ID上下文。 while循环只读取文件，SOC恰好是文件中的第一个条目，因此它会立即中断。

    while((values=validation.readLine())!=null) {
        valuesArray=values.split(",");
        if(valuesArray[2].equals("SchoolofCommunication")) {
            school = "SOC";
            break;
        }

        // this else branch is not reachable based on the contents of the file
        else if(valuesArray[2].equals("SchoolofEngineering")) {
            school = "SOE";
            break;
        }

    }

所以你需要传递ID上下文：

second(String id)

并在while循环中使用它来查找文件中的相关行：

    while((values=validation.readLine())!=null) {
        valuesArray=values.split(",");
        if(valuesArray[0].equals(id) && valuesArray[2].equals("SchoolofCommunication")) {
            school = "SOC";
            break;
        } else if((valuesArray[0].equals(id) && valuesArray[2].equals("SchoolofEngineering")) {
            school = "SOE";
            break;
        }
    }

根据登录ID java从文件中提取数据

1 个答案: