This is the piece of code where key is of type String and value is List, but when i collecting all list elements and adding same to MultiMap object its adding as [[]], The intension of using MultiMap is due to im having same key with different values (here “$.name” is having multiple values) this …
Tag: hashmap
How does get method works in hashmap if hashcode returns a contant value and equals return false?
I have Dept class as follows, i have overridden hashcode and equals method. Hashcode returns a constant value and equals return false always. I have a main method According to the theory i have read, hashcode returning a constant value will give us the same index of bucket in hashmap hence values are stored i…
Converting String number words to just String number:Java
I’m a beginner coder trying to work on converter for words which should work that way:Input= “zero;six;eight;two” Output = “0682”. But in my case the output I get is “0282”. Are there any solutions to that? Or like maybe I should program differently?. I found that Lin…
Create arraylist from list of maps for certain key value with java 8
I have an object with a list of maps. Each map looks like this: I am trying to create an array list of all the id’s in the maps. I can do this with a simple loop But how is this done in one line using java 8 streams? I have never used it with maps so I am lost.
Static method to count occurrences of a letter in a lower case word using maps
I have to create a class called MakeMap with a single static method called countLetters(). The method should take as a parameter a word formed of lowercase letters and return a map of the counts of …
Converting string to Map in java 8
Can someone please guide me on how to achieve the below using Java 8. I don’t know how to get that counter as the key Answer You can use IntStream to get this thing done. Use the integer value as the key, and the relevant value in the string array at that index as the value of the map. Another
handle duplicate key in Collectors.toMap() function
I am creating a map which its (key,value) will be (name, address) in my Person object: In the duplicate key situation, I would like to skip to add the second address to the map and would like to log the name also. Skipping the duplicate address I can do already using mergeFunction, but in oder to log the name…
How can I store nested Hashmap in Redis?
I want to store netsted HashMap in Redis having single key. For example : Please Suggest : Is there any way to store the above-mentioned data structure? How can we achieve this? Answer Redis doesn’t support it as of now. However there is a way to do it, other than rejson. You can convert it into JSON an…
java.util.Map values() method performance
I have a map like this with several million entries: I need to get list of values, which could be done by calling java.util.Map values() method. Is Collection of values created every time I call values() method or is it pre-computed from performance perspective? As my Map has several millions elements, I do n…
map inside a map – Need data in specific format
I have a requirement where I want to read multiple project pom files and display data in below format My coding is getting input on project , ver and technlogy and displaying, but however I couldnt second value inside the internal Please help me understand why I couldnt add 2nd key value pair to Internal map?…