1.application.properties配置文件

# config for mysql
spring.datasource.url = jdbc\:mysql\://127.0.0.1\:3306/数据库名?characterEncoding\=utf8&useSSL\=false
spring.datasource.username = 账号
spring.datasource.password = 密码
spring.datasource.validation-query= SELECT 1
spring.jpa.properties.hibernate.dialect =org.hibernate.dialect.MySQL5Dialect
#spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.driver
# ================ 重连配置 ================
# 最大重试次数
spring.datasource.druid.connection-error-retry-attempts=10
# 重试间隔时间（毫秒）
spring.datasource.druid.time-between-connect-error-millis=10000
# 获取连接失败后中断
spring.datasource.druid.break-after-acquire-failure=false# 自定义监控配置
monitoring.database.enabled=true
#30秒检查一次
monitoring.database.interval=30000
#5秒超时
monitoring.database.connection-timeout=5000

2.引入对应依赖

          <dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.33</version><!-- 明确排除旧版依赖冲突 --><exclusions><exclusion><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></exclusion></exclusions></dependency><!-- Druid 连接池 --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.16</version></dependency>
<!-- Spring Actuator for Health Checks --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency>
<!-- 内置的有Schedul的依赖 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency>

3.代码实现

package com.dianju.signatureServer;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import srvSeal.SrvSealUtil;import javax.annotation.PostConstruct;
import java.sql.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;@RestController
@RequestMapping("/monitorservice")
public class MonitorController {private final Logger log = LoggerFactory.getLogger(this.getClass());@Value("${spring.datasource.url}")private String jdbcUrl;@Value("${spring.datasource.username}")private String username;@Value("${spring.datasource.password}")private String password;@Value("${spring.datasource.validation-query}")private String validationQuery;@Value("${monitoring.database.interval}")private long checkInterval;@Value("${monitoring.database.connection-timeout}")private int connectionTimeout;// 状态跟踪变量private final AtomicInteger consecutiveFailures = new AtomicInteger(0);private final AtomicLong lastFailureTime = new AtomicLong(0);private final AtomicLong lastSuccessTime = new AtomicLong(System.currentTimeMillis());@Autowiredprivate SrvSealUtil srvSealUtil;@PostConstructpublic void init() {try {// 显式加载MySQL驱动Class.forName("com.mysql.cj.jdbc.Driver");log.info("✅ MySQL驱动加载成功");// 打印配置信息log.info("数据库监控配置:");log.info("连接URL: {}", jdbcUrl);log.info("用户名: {}", username);log.info("验证查询: {}", validationQuery);log.info("监控间隔: {}ms", checkInterval);log.info("连接超时: {}ms", connectionTimeout);} catch (ClassNotFoundException e) {log.error("❌ 加载MySQL驱动失败", e);throw new RuntimeException("数据库驱动加载失败", e);}}@Scheduled(fixedRateString = "${monitoring.database.interval}")public void monitorDatabase() {long startTime = System.currentTimeMillis();boolean isHealthy = checkDatabaseHealth();long responseTime = System.currentTimeMillis() - startTime;if (isHealthy) {handleSuccess(responseTime);} else {handleFailure();}}private boolean checkDatabaseHealth() {try (Connection conn = DriverManager.getConnection(buildConnectionUrl(),username,password)) {try (Statement stmt = conn.createStatement();ResultSet rs = stmt.executeQuery(validationQuery)) {return rs.next() && rs.getInt(1) == 1;}} catch (Exception e) {log.error("❌ 数据库健康检查失败", e);return false;}}// 正确构建带超时的连接URLprivate String buildConnectionUrl() {StringBuilder urlBuilder = new StringBuilder(jdbcUrl);if (jdbcUrl.contains("?")) {urlBuilder.append("&connectTimeout=").append(connectionTimeout);} else {urlBuilder.append("?connectTimeout=").append(connectionTimeout);}return urlBuilder.toString();}private void handleSuccess(long responseTime) {// 重置失败计数器consecutiveFailures.set(0);// 更新最后成功时间lastSuccessTime.set(System.currentTimeMillis());// 如果之前有失败记录，输出恢复信息if (lastFailureTime.get() > 0) {long downTime = System.currentTimeMillis() - lastFailureTime.get();log.info("\n🔥 数据库恢复可用! 宕机时长: {}秒\n", downTime / 1000);// 重置失败时间戳lastFailureTime.set(0);}// 输出正常日志log.info("✅ 数据库正常 | 响应时间: {}ms", responseTime);}private void handleFailure() {// 增加失败计数int failures = consecutiveFailures.incrementAndGet();// 记录第一次失败时间if (failures == 1) {lastFailureTime.set(System.currentTimeMillis());}// 获取宕机时长（秒）long downTime = 0;if (lastFailureTime.get() > 0) {downTime = (System.currentTimeMillis() - lastFailureTime.get()) / 1000;}// 输出错误日志log.error("❌ 数据库连接失败 | 连续失败次数: {} | 宕机时长: {}秒", failures, downTime);}// 获取数据库状态（供其他服务查询）public boolean isDatabaseUp() {return consecutiveFailures.get() == 0;}// 获取数据库最后健康时间public long getLastHealthyTime() {return lastSuccessTime.get();}}

断开mysql连接，会自动尝试重连，并记录宕机时长