Umgang mit der Verarbeitung und Speicherung großer Datenmengen in Java

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class DataProcessor {
    public static void main(String[] args) {
        int numThreads = 4; // 设置线程数量

        // 创建线程池
        ExecutorService executorService = Executors.newFixedThreadPool(numThreads);

        // 分片处理数据
        for (int i = 0; i < numThreads; i++) {
            final int index = i;
            executorService.execute(() -> {
                processData(index); // 处理数据的方法
            });
        }

        // 等待所有线程完成处理
        executorService.shutdown();
        try {
            executorService.awaitTermination(Long.MAX_VALUE, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    private static void processData(int index) {
        // 处理数据的逻辑
        System.out.println("Processing data in thread " + index);
    }
}

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

import java.util.concurrent.TimeUnit;

public class DataCache {
    private static Cache<String, String> cache;

    public static void main(String[] args) {
        int maxSize = 100000; // 缓存最大容量
        int expireTime = 10; // 缓存过期时间（单位：分钟）

        // 创建缓存
        cache = CacheBuilder.newBuilder()
                .maximumSize(maxSize)
                .expireAfterWrite(expireTime, TimeUnit.MINUTES)
                .build();

        // 添加数据到缓存
        for (int i = 0; i < maxSize; i++) {
            String key = "key" + i;
            String value = "value" + i;
            cache.put(key, value);
        }

        // 从缓存中获取数据
        for (int i = 0; i < maxSize; i++) {
            String key = "key" + i;
            String value = cache.getIfPresent(key);
            if (value != null) {
                System.out.println("Value for key " + key + ": " + value);
            }
        }
    }
}

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DatabaseAccess {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String DB_USER = "root";
    private static final String DB_PASSWORD = "password";

    public static void main(String[] args) {
        Connection connection = null;
        Statement statement = null;
        ResultSet resultSet = null;

        try {
            // 连接数据库
            connection = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            statement = connection.createStatement();

            // 执行查询
            String query = "SELECT * FROM mytable WHERE id = 1";
            resultSet = statement.executeQuery(query);

            // 处理结果
            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                System.out.println("ID: " + id + ", Name: " + name);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (resultSet != null) resultSet.close();
                if (statement != null) statement.close();
                if (connection != null) connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}