1. 前言
Druid数据库连接池由阿里巴巴开源,号称是java语言中最好的数据库连接池,是为监控而生的。Druid的官方地址是:https://github.com/alibaba/druid
通过本文,我们可以看到
- Spring Boot 如何配置数据源
- Spring Boot 如何集成Druid数据库连接池
- 如何打开并访问Druid数据库连接池的监控功能
- Spring Boot 使用JdbcTemplate操作数据库
2. 配置pom.xml
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< parent > < groupId >org.springframework.boot</ groupId > < artifactId >spring-boot-starter-parent</ artifactId > < version >1.3.5.RELEASE</ version > </ parent > < properties > < project.build.sourceEncoding >UTF-8</ project.build.sourceEncoding > < project.reporting.outputEncoding >UTF-8</ project.reporting.outputEncoding > < java.version >1.8</ java.version > </ properties > < dependencies > < dependency > < groupId >org.springframework.boot</ groupId > < artifactId >spring-boot-starter-web</ artifactId > </ dependency > < dependency > < groupId >org.springframework.boot</ groupId > < artifactId >spring-boot-starter-jdbc</ artifactId > </ dependency > < dependency > < groupId >com.alibaba</ groupId > < artifactId >druid</ artifactId > < version >1.0.20</ version > </ dependency > < dependency > < groupId >org.postgresql</ groupId > < artifactId >postgresql</ artifactId > < scope >runtime</ scope > </ dependency > </ dependencies > |
3. 在application.properties中配置数据源
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# 数据库访问配置,此处使用postgres为例。 # 主数据源,默认的 spring.datasource.type=com.alibaba.druid.pool.DruidDataSource spring.datasource.driver-class-name=org.postgresql.Driver spring.datasource.url=jdbc:postgresql://192.168.1.9/jianshudb spring.datasource.username=postgres spring.datasource.password=yourpassword # 下面为连接池的补充设置,应用到上面所有数据源中 # 初始化大小,最小,最大 spring.datasource.initialSize=5 spring.datasource.minIdle=5 spring.datasource.maxActive=20 # 配置获取连接等待超时的时间 spring.datasource.maxWait=60000 # 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒 spring.datasource.timeBetweenEvictionRunsMillis=60000 # 配置一个连接在池中最小生存的时间,单位是毫秒 spring.datasource.minEvictableIdleTimeMillis=300000 # Oracle请使用select 1 from dual spring.datasource.validationQuery=SELECT 'x' spring.datasource.testWhileIdle=true spring.datasource.testOnBorrow=false spring.datasource.testOnReturn=false # 打开PSCache,并且指定每个连接上PSCache的大小 spring.datasource.poolPreparedStatements=true spring.datasource.maxPoolPreparedStatementPerConnectionSize=20 # 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙 spring.datasource.filters=stat,wall,slf4j # 通过connectProperties属性来打开mergeSql功能;慢SQL记录 #spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 # 合并多个DruidDataSource的监控数据 #spring.datasource.useGlobalDataSourceStat=true |
DruidDataSource参考配置:
https://github.com/alibaba/druid/wiki/%E9%85%8D%E7%BD%AE_DruidDataSource%E5%8F%82%E8%80%83%E9%85%8D%E7%BD%AE
4. 打开Druid的监控统计功能
Druid的监控统计功能是通过filter-chain扩展实现,如果你要打开监控统计功能,需要配置StatFilter,相关代码如下。
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@Configuration public class DruidConfiguration { private static final Logger log = LoggerFactory.getLogger(DruidConfiguration. class ); @Bean public ServletRegistrationBean druidServlet() { log.info( "init Druid Servlet Configuration " ); ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(); servletRegistrationBean.setServlet( new StatViewServlet()); servletRegistrationBean.addUrlMappings( "/druid/*" ); Map<String, String> initParameters = new HashMap<String, String>(); initParameters.put( "loginUsername" , "admin" ); // 用户名 initParameters.put( "loginPassword" , "admin" ); // 密码 initParameters.put( "resetEnable" , "false" ); // 禁用HTML页面上的“Reset All”功能 initParameters.put( "allow" , "" ); // IP白名单 (没有配置或者为空,则允许所有访问) //initParameters.put("deny", "192.168.20.38");// IP黑名单 (存在共同时,deny优先于allow) servletRegistrationBean.setInitParameters(initParameters); return servletRegistrationBean; } @Bean public FilterRegistrationBean filterRegistrationBean() { FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(); filterRegistrationBean.setFilter( new WebStatFilter()); filterRegistrationBean.addUrlPatterns( "/*" ); filterRegistrationBean.addInitParameter( "exclusions" , "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*" ); return filterRegistrationBean; } } |
等应用启动后,可以访问地址:http://localhost:8080/druid/,用户名和密码见上述代码中的设置,即admin/admin。
5. 使用JdbcTemplate操作数据库
假设数据库中有表t_user,其中id=1的user的username为ZhangSan。下面的例子演示了通过id查找username的情况。
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@RestController public class DemoController { @Autowired JdbcTemplate jdbcTemplate; @RequestMapping (value = "/hello.do" , method = RequestMethod.GET) public String hello( @RequestParam (value = "id" , required = true ) Integer id) { String name = getNameById(id); return (name == null ) ? "Hello World" : ( "Hello " + name); } public String getNameById(Integer id) { String sql = "select username from t_user where id = ? " ; List<String> list = jdbcTemplate.queryForList(sql, new Object[] {id}, String. class ); return list.isEmpty() ? null : list.get( 0 ); } } |
访问地址:http://localhost:8080/hello.do?id=1
结果输出:Hello, ZhangSan
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.jianshu.com/p/c8a01ae9f779