Resolving Unchecked Call to put(K, V) on Raw Type java.util.HashMap in JSONObject Usage

How can I resolve the unchecked call to put(K,V) when using java.util.HashMap in a JSONObject?

HashMap<String, Object> map = new HashMap<>();
map.put("key1", "value1");
JSONObject jsonObject = new JSONObject(map);

The warning about an unchecked call to put(K,V) when using java.util.HashMap typically indicates that you are using the raw type of HashMap without generics. This can lead to type safety issues. Using generics appropriately resolves the warning and ensures type safety in your Java code.

HashMap<String, Object> map = new HashMap<>();
map.put("key1", "value1");
map.put("key2", 123); // Correctly adding different types as Object
JSONObject jsonObject = new JSONObject(map);

Causes

• Using a raw type for java.util.HashMap without specifying key and value types.
• Inconsistent data types being inserted into the HashMap due to lack of generics.

Solutions

• Specify the generic types when declaring the HashMap like HashMap<String, Object> to match the types being stored and accessed.
• Ensure that the types for keys and values in the HashMap match the expected types when creating the JSONObject.

Mistake: Declaring a HashMap without specifying generic types, leading to unchecked warnings.

Solution: Always use generics when declaring collections to ensure type safety. For example, HashMap<K,V>.

Mistake: Inserting incompatible types into the HashMap.

Solution: Only insert values that are compatible with the declared type of the HashMap.