我无法在Java中显示属性文件的输出

Question

I'm trying to read from a properties file and displaying the output in a text field but it just gives me a blank page. I know the codes isn't the best but I don't know another way.

Double income = Double.parseDouble(totalField.getText());

Properties prop = new Properties();
InputStream input = null;

try {
    input = new FileInputStream("intput.properties");
    prop.load(input);
    if (income <= 11000) {
        taxMessage.setText(String.valueOf(Double.parseDouble(prop.getProperty("tax"))));
        montaxMessage.setText("mon tax:" + String.valueOf(Double.parseDouble(prop.getProperty("tax")) / 12));
    }
} catch(IOException ex) {
    ex.printStackTrace();
} finally {
    if (input != null) {
        try {
            input.close();
        } catch(IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

Your code looks fine. Maybe your file is empty?

Can you try if that code is printing your file?

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class App {
  public static void main(String[] args) {

    Properties prop = new Properties();
    InputStream input = null;

    try {

        input = new FileInputStream("input.properties");
        prop.load(input);

        // get the property value and print it out
        System.out.println(prop.getProperty("tax"));

    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        if (input != null) {
            try {
                input.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

  }
}

Empty? You can add data the code below:

output = new FileOutputStream("config.properties");

// set the properties value
prop.setProperty("database", "localhost");
prop.setProperty("dbuser", "mkyong");
prop.setProperty("dbpassword", "password");

// save properties to project root folder
prop.store(output, null);

Also I think you can skip one step and use:

taxMessage.setText(prop.getProperty("tax"));