Part V Druid data source introduction

Introduction
   Everyone has been using Druid, But never studied Druid What is it ？Druid The first is a database connection pool .Druid Is the best database connection pool available , In the functional 、 performance 、 extensibility , All over the other database connection pool , Include DBCP、C3P0、BoneCP、Proxool、JBoss DataSource.Druid More than has been deployed in alibaba 600 Applications , After more than a year of large-scale deployment in production environments .Druid Is a database connection pool developed by alibaba that it claims was created for surveillance ！ Now let's take you to study Druid.

  Druid It's a JDBC Components , It mainly includes the following three parts

• DruidDriver agent Driver, Be able to provide based on Filter-Chain Pattern plug-in system
• DruidDataSource It can efficiently manage the database connection pool
• SQLParser

Druid What can be done ？

• 1、 It can monitor the performance related data of database access ,Druid Built in provides powerful StatFilter plug-in unit , Be able to count SQL Execution performance , It is very helpful for online analysis .
• 2、 To replace the DBCP and C3P0 Database connection pool .Druid Provides a more efficient 、 Powerful performance 、 Highly scalable database connection pool .
• 3、 Generally in development , We write the database password in the configuration file , Such operation is extremely unsafe ,DruidDruiver and DruidDataSource It's all supported PasswordCallback operation .
• 4、SQL Execution log ,Druid Offers a different one LogFilter, Able to support Common-Logging、Log4j and JDKlog, You can choose the corresponding LogFilter,