高并发下的连接数优化与资源限制

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

public class ConnectionPoolExample {
    public static void main(String[] args) {
        HikariConfig config = new HikariConfig();
        config.setJdbcUrl("jdbc:mysql://localhost:3306/mydb");
        config.setUsername("user");
        config.setPassword("password");
        config.setMaximumPoolSize(10);
        config.setMinimumIdle(5);
        config.setConnectionTimeout(30000);
        config.setIdleTimeout(600000);
        config.setMaxLifetime(1800000);

        HikariDataSource ds = new HikariDataSource(config);
        // 使用连接池获取连接
        try (Connection connection = ds.getConnection()) {
            // 执行数据库操作
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

import java.util.concurrent.atomic.AtomicLong;

public class TokenBucket {
    private final long capacity;
    private final long refillRate;
    private AtomicLong tokens;
    private long lastRefillTimestamp;

    public TokenBucket(long capacity, long refillRate) {
        this.capacity = capacity;
        this.refillRate = refillRate;
        this.tokens = new AtomicLong(capacity);
        this.lastRefillTimestamp = System.currentTimeMillis();
    }

    public synchronized boolean tryConsume() {
        refill();
        if (tokens.get() > 0) {
            tokens.decrementAndGet();
            return true;
        }
        return false;
    }

    private void refill() {
        long now = System.currentTimeMillis();
        long elapsed = now - lastRefillTimestamp;
        long newTokens = elapsed * refillRate / 1000;
        if (newTokens > 0) {
            long currentTokens = tokens.get();
            long updatedTokens = Math.min(capacity, currentTokens + newTokens);
            tokens.set(updatedTokens);
            lastRefillTimestamp = now;
        }
    }
}