Printing a java map Map<String, Object> - How? [duplicate]

Question

How to I print information from a map that has the object as the value?

I have created the following map:

Map<String, Object> objectSet = new HashMap<>(); 

The object has its own class with its own instance variables

I have already populated the above map with data.

I have created a printMap method, but I can only seem to print the Keys of the map

How to do I get the map to print the <Object> values using a for each loop?

So far, I've got:

for (String keys : objectSet.keySet()) {    System.out.println(keys); } 

The above prints out the keys. I want to be able to print out the object variables too.

Answer 1

I'm sure there's some nice library that does this sort of thing already for you... But to just stick with the approach you're already going with, Map#entrySet gives you a combined Object with the key and the value. So something like:

for (Map.Entry<String, Object> entry : map.entrySet()) {     System.out.println(entry.getKey() + ":" + entry.getValue().toString()); } 

will do what you're after.

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If you're using java 8, there's also the new streaming approach.

map.forEach((key, value) -> System.out.println(key + ":" + value)); 

Answer 2

You may use Map.entrySet() method:

for (Map.Entry entry : objectSet.entrySet()) {     System.out.println("key: " + entry.getKey() + "; value: " + entry.getValue()); }