用java写一个多线程读取json

下面是一个用Java多线程读取JSON文件的示例代码：

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.json.JSONArray;
import org.json.JSONObject;

public class MultiThreadedJSONReader {

    public static void main(String[] args) {
        String filePath = "example.json";
        int numThreads = 4;
        ExecutorService executor = Executors.newFixedThreadPool(numThreads);

        try (BufferedReader reader = new BufferedReader(new FileReader(filePath))) {
            String line;
            JSONArray jsonArray = new JSONArray();
            while ((line = reader.readLine()) != null) {
                jsonArray.put(new JSONObject(line));
            }

            int chunkSize = (int) Math.ceil(jsonArray.length() / (double) numThreads);
            for (int i = 0; i < numThreads; i++) {
                int start = i * chunkSize;
                int end = Math.min(start + chunkSize, jsonArray.length());
                JSONArray chunk = new JSONArray(jsonArray.toString(start, end));
                executor.execute(new JSONReaderRunnable(chunk));
            }
        } catch (IOException e) {
            System.err.println("Error reading file: " + e.getMessage());
        }

        executor.shutdown();
    }

    private static class JSONReaderRunnable implements Runnable {
        private final JSONArray jsonArray;

        public JSONReaderRunnable(JSONArray jsonArray) {
            this.jsonArray = jsonArray;
        }

        @Override
        public void run() {
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                // Do something with the JSON object
            }
        }
    }
}

这个示例代码将一个JSON文件分成多个块，然后为每个块创建一个线程来处理。在这个示例中，使用了Java的`ExecutorService`和`Runnable`接口来实现多线程处理。每个JSON块由一个`JSONReaderRunnable`对象处理。你可以在`JSONReaderRunnable`类的`run()`方法中编写代码来处理JSON对象。