Java Properties and lambda collect

Question

I have a method that convert Properties into hashmap in this way (i know it's wrong)

Map<String, String> mapProp = new HashMap<String, String>();
Properties prop = new Properties();
prop.load(new FileInputStream( path ));     

prop.forEach( (key, value) -> {mapProp.put( (String)key, (String)value );} );

return mapProp;

My idea is that mapping in a way like this:

Properties prop = new Properties();
prop.load(new FileInputStream( path ));

Map<String, String> mapProp = prop.entrySet().stream().collect( /*I don't know*/ );

return mapProp;

How write a lambda expression for do that?

Thanks all in advance

Andrea.

Solution 1

Use Collectors.toMap

Properties prop = new Properties();
prop.load(new FileInputStream( path ));

Map<String, String> mapProp = prop.entrySet().stream().collect(
    Collectors.toMap(
        e -> (String) e.getKey(),
        e -> (String) e.getValue()
    ));

Solution 2

Not actually an answer but may be useful to know for others passing by.

Since Properties extends Hashtable<Object,Object> which implements Map<K,V> you should not need to do anything other than:

    Properties p = new Properties();
    Map<String,String> m = new HashMap(p);

Not quite sure why no warnings are offered for this code as it implies a cast from Map<Object,Object> to Map<String,String> is acceptable but I suspect that is a separate question.

Solution 3

for those who want to use forEach

HashMap<String, String> propMap = new HashMap<>();
prop.forEach((key, value)-> {
   propMap.put( (String)key, (String)value);
});