Populating a HashMap with entries from a properties file

Question

I want to populate a HashMap using the Properties class.
I want to load the entries in the .propeties file and then copy it into the HashMap.

Earlier, I used to just initialize the HashMap with the properties file, but now I have already defined the HashMap and want to initialize it in the constructor only.

Earlier approach:

Properties properties = new Properties();

try {
    properties.load(ClassName.class.getResourceAsStream("resume.properties"));
} catch (Exception e) { 

}

HashMap<String, String> mymap= new HashMap<String, String>((Map) properties);

But now, I have this

public class ClassName {
HashMap<String,Integer> mymap = new HashMap<String, Integer>();

public ClassName(){

    Properties properties = new Properties();

    try {
      properties.load(ClassName.class.getResourceAsStream("resume.properties"));
    } catch (Exception e) {

    }
    mymap = properties;
    //The above line gives error
}
}

How do I assign the properties object to a HashMap here?

Solution 1

If I understand correctly, each value in the properties is a String which represents an Integer. So the code would look like this:

for (String key : properties.stringPropertyNames()) {
    String value = properties.getProperty(key);
    mymap.put(key, Integer.valueOf(value));
}

Solution 2

Use .entrySet()

for (Entry<Object, Object> entry : properties.entrySet()) {
    map.put((String) entry.getKey(), (String) entry.getValue());
}

Solution 3

Java 8 Style:

Properties properties = new Properties();
// add  some properties  here
Map<String, String> map = new HashMap();

map.putAll(properties.entrySet()
                     .stream()
                     .collect(Collectors.toMap(e -> e.getKey().toString(), 
                                               e -> e.getValue().toString())));

Solution 4

public static Map<String,String> getProperty()
    {
        Properties prop = new Properties();
        Map<String,String>map = new HashMap<String,String>();
        try
        {
            FileInputStream inputStream = new FileInputStream(Constants.PROPERTIESPATH);
            prop.load(inputStream);
        }
        catch (Exception e) {
            e.printStackTrace();
            System.out.println("Some issue finding or loading file....!!! " + e.getMessage());

        }
        for (final Entry<Object, Object> entry : prop.entrySet()) {
            map.put((String) entry.getKey(), (String) entry.getValue());
        }
        return map;
    }

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