In this Java example code, we have made a HashMap object named m1 (Key: Integer, Value: String). We then insert some key-value pairs into the HashMap. After printing the map, we then use getOrDefault() in Java to access some values based on their mappings with the specified keys. Clearly, value1 will be initialized with the value "C++" which is mapped with key 1 and since, the map doesn't contain any mapping for key 5, value2 will be initialized with the default value - "Not found!". We will then print the values at the end.

m1.getOrDefault(5,"Not Found!"); Here, 5 is the key whose mapped value is to be returned, and "Not Found!" is the default valued string that will be returned when we don't have any mapping of key 5 in the HashMap.

In this Java example code, we will be storing English Alphabets in the HashMap in order of their occurrence. We have made a HashMap object named m1 (Key: Character,Value: Integer). We will then insert the character-integer value pairs of English Alphabets into the m1 HashMap. For Example: 'A' will be mapped to 1, 'B' will be mapped to 2, and so on. After printing the HashMap, we will then use getOrDefault() in Java in order to target some key-value pairs to print their mapped values. Clearly, value1 will be initialized with 13, which is the mapped value of key - 'M', and value2 will be initialized with 404, which is the default value for key - '@' returned. We will print these values at the end.

m1.getOrDefault('@',404); Here, '@' is the key whose mapped value is to be returned, and 404 is the default value that will be returned when we don't have any mapping of key '@' in the HashMap.

In this Java example code, we are doing something unique and out-of-the-box. Extending the use-case of Example 2, we have HashMap m1, and all English Alphabets are stored in it according to their occurrence. Now, user will be prompted to enter the string str, and we will try to sum all the mapped values of all the characters of the string. getOrDefault() method will be used, which will return the mapped value of the specified key, and the default value will be set to -1. This indicates that if the string contains any character out of {"A-Z"}, then it will decrement the sum by 1. After doing this, the resultant sum value will be printed at the end.

Here assuming the entered string is "SCALER" and according to the reference with the HashMap (m1), we have {S:19, C:3, A:1, L:12, E:5, R:18} Adding all these values to the sum, we get the result 58.

Here assuming the entered string is "ABC#" and according to the reference with the HashMap (m1), we have {A:1, B:2, C:3, #:-1} Character '#' doesn't exist in the HashMap and, thus, will have its default value -1. Adding all these values to the sum, we get the result 5.