Java Swing Calculator，它使用文件处理来保存和读取数字，即使在关闭程序时也是如此

Question

我正在用Java Swing库开发一个简单的GUI计算器，遇到了找不到解决方案的问题。我只是在学习Java，所以如果问题很简单，不要严格评判我。

我的问题的主要思想是，我正在尝试使用Java.io"文件处理"；将数字保存到文件中，并在文本字段中重新打开计算器时获取该数字。

这是代码：

public void actionPerformed (ActionEvent e) 
{
//---------------------------------------------------------------
if (e.getSource() == button_save) {
save = mytext.getText();
writeF(save); // problem is here "Unhandled exception type IOException"
}
else if (e.getSource() == button_recall) {
recall = readF(); // also here
mytext.setText(recall);
}

用户定义方法

public static void writeF(String memory)throws IOException{
FileWriter writehandle = new FileWriter("C:\Users\Public\Documents\memory.txt");
BufferedWriter bw = new BufferedWriter(writehandle);

bw.write(memory);
bw.close();
writehandle.close();
}
public static String readF()throws IOException{
FileReader readhandle = new FileReader("C:\Users\Public\Documents\memory.txt");
BufferedReader br = new BufferedReader(readhandle);

String num = br.readLine();

br.close();
readhandle.close();

return num;
}

完整的代码你可以在这里找到

Answer 1

解决方案：

else if (e.getSource() == button_save) {
save = mytext.getText();
try
{
writeF(save);
}
catch (IOException e1)
{
e1.printStackTrace();
} // problem is here "Unhandled exception type IOException"
}
else if (e.getSource() == button_recall) {
try 
{
recall = readF();
} 
catch (IOException e1) 
{
e1.printStackTrace();
} // also here
mytext.setText(recall);
}