java - 是否可以从文本文件中读取多行并将其导出到各自的文本字段？

Question

private void loadActionPerformed(java.awt.event.ActionEvent evt) {                                     
    // TODO add your handling code here:
    try{
        FileReader reader = new FileReader("reload.txt");
        BufferedReader br = new BufferedReader(reader);
        koontf.read(br,null);
        baamtf.read(br,null);
        sachitf.read(br,null);
        fakertf.read(br,null);
        phonsekaltf.read(br,null);
        lauretf.read(br,null);
        yeontf.read(br,null);
        aguerotf.read(br,null);
        agnistf.read(br,null);
        lokitf.read(br,null);
        lawliettf.read(br,null);
        ryuzakitf.read(br,null);
        br.close();
        koontf.requestFocus();
        baamtf.requestFocus();
        sachitf.requestFocus();
        fakertf.requestFocus();
        phonsekaltf.requestFocus();
        lauretf.requestFocus();
        yeontf.requestFocus();
        aguerotf.requestFocus();
        agnistf.requestFocus();
        lokitf.requestFocus();
        lawliettf.requestFocus();
        ryuzakitf.requestFocus();

    }catch(IOException e) {

    }
}                                    

Is it even possible to put each of them to a certain textfield?Like 12 to jtextfield1,10 to jtextfield2 and so on...I've tried some tutorials and can't really figure it out.

Answer 1

您可以将所有文本字段放在一个数组中，然后在读取文本文件时遍历该数组。像这样:

JTextField[] textFields = new JTextField[10];
// ... init your textFields here

int line =0;  // first line will be first textfield and so on
Scanner scanner = new Scanner(new File("reload.txt"));  // use Scanner instead of FileReader, it's easier :) 
while(scanner.hasNextLine()){   // as long as you did not reach the end of the file
    textFields[line++].setText(scanner.nextLine()); // get the next line and put it in the respective textfield
}

但是，在这种情况下，您必须确保每一行都有一个文本字段，或者您阅读的行数不超过文本字段数。

例如:

while(.....){
   ....
   if(line==textFields.length){
       break;
   }
}

另一件需要注意的事情是，行的顺序必须与文本字段的顺序相对应。

编辑
我必须补充一点，所有这些都可以毫无问题地工作。但这不是一个非常优雅的解决方案。当您更改 UI 并且文本字段的顺序不同时会发生什么？或者在您的文本文件中有一个重要的新行但在您的 UI 中没有 TextField？

编辑2
您评论中的代码没有显示您如何将 JTextFields 放入数组中。我的猜测是您正在使用某些 IDE 来创建 GUI，因此您应该在构造函数中调用 initComponents(); 或其他内容。在这种情况下，从 loadActionPerformed 方法中删除行 JTextField[] textFields = new JTextField[10]; 并将其放入构造函数中，如下所示:

public class MyClass{

     private JTextField[] textFields;

     public MyClass(){
         initComponents();
         this.textFields = new JTextField[10]  // where 10 is the number of lines in your textfile AND the number of JTextFields you have in your GUI
         // then fill the array (by hand if you like)
         this.textField[0] = koontf;
         this.textField[1] = baamtf;
         // and so on..
     }

编辑 3
只是为了清楚起见，这是让程序运行所需要的。假设您的类(class)名为 MyClass，那么它可能如下所示:

private JTextField[] textFields;  // this creates your array

public MyClass(){        // this is the constructor of your class (I don't know how it is called) 
    initComponents();    // auto generated code from NetBeans to initalize your GUI elements
    // init your array
    textFields = new JTextField[12];  // 12 if I counted correctly
    // fill it
    textFields[0] = koontf;
    textFields[1] = baamtf;
    textFields[2] = sachitf;
    textFields[3] = fakertf;
    textFields[4] = phonsekaltf;
    textFields[5] = lauretf;
    textFields[6] = yeontf;
    textFields[7] = aguerotf;
    textFields[8] = agnistf;
    textFields[9] = lokitf;
    textFields[10] = lawliettf;
    textFields[11] = ryuzakitf;
}

private void loadActionPerformed(java.awt.event.ActionEvent evt){
    int line = 0;
    try(Scanner scanner = new Scanner(new File("reload.txt"))){
        while(scanner.hasNextLine()){
            textFields[line++].setText(scanner.nextLine());
            if(line == textFields.length){
                break;
            }
        }
    }catch(FileNotFoundException ex){
        Logger.getLogger(MyClass.class.getName()).log(Level.SEVERE, null, ex);
    }
    koontf.requestFocus();  // you can only call request focus on one element at a time (it does not make sense to call it on all textfields
}