To convert a JSONArray to a List＜Map＜String, String＞＞ in Java

hshpy2025-02-12 16:43

To convert a JSONArray to a List<Map<String, String>> in Java, you can utilize the Jackson library's ObjectMapper for efficient parsing. Here's how you can achieve this:

1. Add Jackson Dependency:

Ensure that the Jackson library is included in your project. If you're using Maven, add the following dependency to your pom.xml:

XML 复制代码

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.17.0</version>
</dependency>

2. Convert JSONArray to List<Map<String, String>>:

Assuming you have a JSON array string, you can parse it as follows:

java 复制代码

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonArrayToListMap {
    public static void main(String[] args) {
        String jsonArray = "[{\"key1\":\"value1\", \"key2\":\"value2\"}, {\"keyA\":\"valueA\", \"keyB\":\"valueB\"}]";
        ObjectMapper mapper = new ObjectMapper();

        try {
            // Convert JSON array string to List<Map<String, String>>
            List<Map<String, String>> list = mapper.readValue(jsonArray, new TypeReference<List<Map<String, String>>>(){});

            // Iterate through the list and print each map
            for (Map<String, String> map : list) {
                System.out.println(map);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Explanation:

ObjectMapper: Jackson's ObjectMapper is a powerful tool for converting between Java objects and JSON.
TypeReference: The TypeReference is used to define the target type for the conversion. In this case, it's a List<Map<String, String>>.
readValue: This method reads the JSON input and converts it into the specified type.
java 复制代码
```
{key1=value1, key2=value2}
{keyA=valueA, keyB=valueB}
```
This approach ensures that your JSON array is accurately converted into a list of maps, with each JSON object represented as a Map<String, String> in the list.