Revert "use custom connection validator instead of sending SELECT 1 query"

This reverts commit f6816a26.

apollo-common/src/main/java/com/ctrip/framework/apollo/common/utils/DataSourceValidator.java

-package com.ctrip.framework.apollo.common.utils;
-
-import org.apache.tomcat.jdbc.pool.Validator;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.sql.Connection;
-
-/**
- * @author Jason Song(song_s@ctrip.com)
- */
-public class DataSourceValidator implements Validator {
-  private static final Logger LOGGER = LoggerFactory.getLogger(DataSourceValidator.class);
-  private static final int DEFAULT_VALIDATE_TIMEOUT_IN_SECONDS = 5;
-
-  @Override
-  public boolean validate(Connection connection, int validateAction) {
-    boolean isValid = false;
-    try {
-      isValid = connection.isValid(DEFAULT_VALIDATE_TIMEOUT_IN_SECONDS);
-    } catch (Throwable ex) {
-      LOGGER.warn("Data source validation error", ex);
-    }
-
-    return isValid;
-  }
-}

apollo-common/src/main/resources/application.properties

@@ -3,8 +3,7 @@ spring.http.converters.preferred-json-mapper=gson
 # DataSource
 spring.datasource.testWhileIdle=true
 spring.datasource.testOnBorrow=true
-spring.datasource.validatorClassName=com.ctrip.framework.apollo.common.utils.DataSourceValidator
-spring.datasource.validationInterval=5000
+spring.datasource.validationQuery=SELECT 1
 spring.datasource.initSQL=set names utf8mb4
 
 # Naming strategy