1. 表结构设计：

首先，需要考虑到Prometheus集成的redis exporter监控信息的结构。通过查看redis exporter的metrics，可以发现其提供了以下几个指标：

• redis_up: 如果Redis实例正常运行，则返回1，否则返回0。
• redis_total_connections_received: Redis实例接收的连接数。
• redis_total_commands_processed: Redis实例处理的命令数量。
• redis_keyspace_hits: Redis实例的键空间命中次数。
• redis_keyspace_misses: Redis实例的键空间未命中次数。
• redis_used_memory: Redis实例使用的内存量。

因此，为了存储这些指标，我们可以设计一个名为”redis_metrics”的表，包含以下字段：

• id：自增主键，用于唯一标识每一条记录。
• instance：Redis实例地址。
• metric_name：指标名称。
• metric_value：指标的值。
• metric_timestamp：指标的时间戳。

1. Java代码实现：

在Java代码中，可以通过Prometheus Java Client来获取redis exporter提供的metrics，并将其存储到MySQL数据库中。以下是一个示例代码：

import io.prometheus.client.Counter;
import io.prometheus.client.Gauge;
import io.prometheus.client.exporter.HTTPServer;
import io.prometheus.client.hotspot.DefaultExports;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.time.Instant;
import java.util.Arrays;
import java.util.List;
public class RedisMetricsExporter {
  private static final String JDBC_URL = "jdbc:mysql://localhost:3306/redis_metrics";
  private static final String JDBC_USER = "root";
  private static final String JDBC_PASSWORD = "password";
  private static final Gauge redisUp = Gauge.build()
      .name("redis_up")
      .help("Redis instance is up and running")
      .register();
  private static final Counter totalConnectionsReceived = Counter.build()
      .name("redis_total_connections_received")
      .help("Total number of connections accepted by Redis server")
      .register();
  private static final Counter totalCommandsProcessed = Counter.build()
      .name("redis_total_commands_processed")
      .help("Total number of commands processed by Redis server")
      .register();
  private static final Counter keyspaceHits = Counter.build()
      .name("redis_keyspace_hits")
      .help("Number of successful key lookups in Redis server")
      .register();
  private static final Counter keyspaceMisses = Counter.build()
      .name("redis_keyspace_misses")
      .help("Number of failed key lookups in Redis server")
      .register();
  private static final Gauge usedMemory = Gauge.build()
      .name("redis_used_memory")
      .help("Amount of memory used by Redis server")
      .register();
  private static final List<String> METRIC_NAMES = Arrays.asList(
      "redis_up",
      "redis_total_connections_received",
      "redis_total_commands_processed",
      "redis_keyspace_hits",
      "redis_keyspace_misses",
      "redis_used_memory"
  );
  public static void main(String[] args) throws Exception {
    // Register Prometheus metrics.
    DefaultExports.initialize();
    HTTPServer server = new HTTPServer(8080);
    // Connect to MySQL database.
    Connection conn = DriverManager.getConnection(JDBC_URL, JDBC_USER, JDBC_PASSWORD);
    while (true) {
      // Fetch Redis metrics from Prometheus.
      double redisUpValue = redisUp.get();
      double totalConnectionsReceivedValue = totalConnectionsReceived.get();
      double totalCommandsProcessedValue = totalCommandsProcessed.get();
      double keyspaceHitsValue = keyspaceHits.get();
      double keyspaceMissesValue = keyspaceMisses.get();
      double usedMemoryValue = usedMemory.get();
      // Insert Redis metrics into MySQL database.
      insertRedisMetrics(conn, redisUpValue, "redis_up");
      insertRedisMetrics(conn, totalConnectionsReceivedValue, "redis_total_connections_received");
      insertRedisMetrics(conn, totalCommandsProcessedValue, "redis_total_commands_processed");
      insertRedisMetrics(conn, keyspaceHitsValue, "redis_keyspace_hits");
      insertRedisMetrics(conn, keyspaceMissesValue, "redis_keyspace_misses");
      insertRedisMetrics(conn, usedMemoryValue, "redis_used_memory");
      // Wait for 1 minute before fetching and inserting metrics again.
      Thread.sleep(60000);
    }
  }
  private static void insertRedisMetrics(Connection conn, double value, String metricName) throws SQLException {
    PreparedStatement stmt = conn.prepareStatement("INSERT INTO redis_metrics (instance, metric_name, metric_value, metric_timestamp) VALUES (?, ?, ?, ?)");
    stmt.setString(1, "localhost:6379");
    stmt.setString(2, metricName);
    stmt.setDouble(3, value);
    stmt.setLong(4, Instant.now().getEpochSecond());
    stmt.execute();
  }
}

该代码会注册Prometheus指标，连接MySQL数据库，并不断地从Prometheus获取Redis监控信息并存储到MySQL中。具体实现中，使用了JDBC来操作数据库，通过PreparedStatement来防止SQL注入攻击。在insertRedisMetrics方法中，将传入的Redis指标值以及时间戳插入到redis_metrics表中。在实际使用时，需要替换JDBC_URL、JDBC_USER和JDBC_PASSWORD为实际的数据库连接信息。