使用相同的多个键读取.txt（属性）文件-Java

Question

In simple java terms, with out using any other libraries (apache), how to i read below lines :

data.txt
    CheckUpdate:  110
    CheckTechNotes:  11
    CheckUpdate:  220
    CheckTechNotes:  21
    CheckUpdate:  330
    CheckTechNotes:  31

Used below code:

public class PropertiesFile {
    public static void main(String[] args) {
        Properties prop = new Properties();
        InputStream input = null;

        try {
            input = new FileInputStream("data.txt");
            prop.load(input);
            Enumeration<?> e = prop.propertyNames();

            while (e.hasMoreElements()) {
                System.out.println(prop.getProperty("CheckUpdate"));
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (input != null) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}

Always returning 330, how do i get 110, 220 and 330 values ?

Note: it's like having 3 employee details in a file, how do i read those 3 employee objects?

Please suggest.

thanks

Answer 1

Property files contain a set of key-value pairs, so it does not make sense to have duplicate keys. The propertyName() call will give you only distinct keys. Just open the file with a normal FileInputStream and scan through your entries instead.

Answer 2

您可以在读取List<String>时添加这些属性，然后以myList.add(prop.getProperty("CheckUpdate"));访问它们myList.add(prop.getProperty("CheckUpdate"));

Answer 3

You likely want to use a structured file format like JSON rather than a flat file format like properties for this type of data. There are many utility libraries available to de-serialize the data such as gson.