Hibernate支持第三方的连接池,官方推荐的连接池是C3P0,Proxool,以及DBCP。在配置连接池时需要注意的有三点:
Hibernate支持第三方的连接池,官方推荐的连接池是C3P0,Proxool,以及DBCP。在配置连接池时需要注意的有三点:
一、Apche的DBCP在Hibernate2中受支持,但在Hibernate3中已经不再推荐使用,官方的解释是这个连接池存在缺陷。如果你因为某种原因需要在Hibernate3中使用DBCP,建议采用JNDI方式。
二、默认情况下(即没有配置连接池的情况下),Hibernate会采用内建的连接池。但这个连接池性能不佳,且存在诸多BUG(笔者在连接oralce数据库的程序中就使用了默认,结果一个晚上没操作隔天就报错说连接已过期),因此官方也只是建议仅在开发环境下使用。
另外,有一些外国文章称C3P0在性能上有点缺陷(它的算法不是最优的),Proxool是*最少的一个。
如果真想使用C3P0,可以参考如下方法:
1.为项目添加jar包——c3p0-0.9.1.jar
2.在hibernate.cfg.xml中添加
完成这两步即可。
建议还是使用高富帅Proxool来配置连接池,如下:
1. 获取proxool
从proxool的官网上下载与使用的hibernate版本相适应的proxool-x.x.x.jar,官网地址是
2.编写proxool的配置文件
在hibernate.cfg.xml相同目录下,创建文件ProxoolConf.xml,内容如下:
注意,实际使用过程中,最好把注释去掉,否则可能会报错,像我就报错了(Proxool Provider unable to load JAXP configurator file:proxool.xml)。。
相关阅读:
Java Web中使用数据库连接池proxool配置详解
Hibernate 的详细介绍:请点这里
Hibernate 的下载地址:请点这里
Hibernate 中文手册 PDF

InnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

MySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Dreamweaver Mac version
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version
Useful JavaScript development tools