Convert LinkedHashMap to String with Separator

Here's how you can convert the linked hashmap into a single string separated by underscores using Java:

import java.util.LinkedHashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        // Create the LinkedHashMap and populate it with the given values
        LinkedHashMap<String, String> map = new LinkedHashMap<>();
        map.put("triggerIdx", "IDX");
        map.put("keywords", "스톤헨지");
        map.put("category", "돌");

        // Check if the map is empty and handle accordingly
        if (map.isEmpty()) {
            System.out.println("The map is empty.");
            return;
        }

        // Initialize a StringBuilder to construct the result string
        StringBuilder result = new StringBuilder();

        // Iterate through the map and append key-value pairs to the result
        for (Map.Entry<String, String> entry : map.entrySet()) {
            if (result.length() > 0) {
                result.append("_");
            }
            result.append(entry.getKey()).append("_").append(entry.getValue());
        }

        // Convert StringBuilder to String and print the result
        String finalString = result.toString();
        System.out.println(finalString);
    }
}

Explanation

1. Create and Populate LinkedHashMap:

   • A LinkedHashMap is created and populated with the given key-value pairs to maintain the insertion order.

2. StringBuilder Initialization:

   • A StringBuilder is used to efficiently build the result string.

3. Iterate Through the Map:

   • The code iterates through the entries of the map. For each entry, it appends the key and value to the StringBuilder, separated by an underscore. If the StringBuilder already contains some text, an additional underscore is added before appending the new key-value pair.

4. Convert to String and Print:

   • The StringBuilder content is converted to a String, which is then printed.

When you run this Java code, it will output:

triggerIdx_IDX_keywords_스톤헨지_category_돌