4、SpringBoot连接数据库引入druid
以前以为druid是用来连接数据库的，其实这样理解不太对，连接数据库还是驱动，druid起到一个连接池的作用，监控管理连接数据库的状态之类的。
1、创建springboot项目
具体步骤参见之前的项目创建文档
2、pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0modelVersion> <groupId>com.examplegroupId> <artifactId>demoartifactId> <version>0.0.1-SNAPSHOTversion> <name>demoname> <description>Demo project for Spring Bootdescription> <properties> <java.version>1.8java.version> <project.build.sourceEncoding>UTF-8project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding> <spring-boot.version>2.1.17.RELEASEspring-boot.version> properties> <dependencies> <dependency> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-jdbcartifactId> dependency> <dependency> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-webartifactId> dependency> <dependency> <groupId>com.oraclegroupId> <artifactId>ojdbc6artifactId> <version>11.2.0.3version> dependency> <dependency> <groupId>com.alibabagroupId> <artifactId>druid-spring-boot-starterartifactId> <version>1.1.10version> dependency> <dependency> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-starter-testartifactId> <scope>testscope> <exclusions> <exclusion> <groupId>org.junit.vintagegroupId> <artifactId>junit-vintage-engineartifactId> exclusion> exclusions> dependency> dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-dependenciesartifactId> <version>${spring-boot.version}version> <type>pomtype> <scope>importscope> dependency> dependencies> dependencyManagement> <build> <plugins> <plugin> <groupId>org.apache.maven.pluginsgroupId> <artifactId>maven-compiler-pluginartifactId> <version>3.8.1version> <configuration> <source>1.8source> <target>1.8target> <encoding>UTF-8encoding> configuration> plugin> <plugin> <groupId>org.springframework.bootgroupId> <artifactId>spring-boot-maven-pluginartifactId> <version>2.1.17.RELEASEversion> <configuration> <mainClass>com.example.demo.DemoApplicationmainClass> configuration> <executions> <execution> <id>repackageid> <goals> <goal>repackagegoal> goals> execution> executions> plugin> plugins> build> project>
3、application.properties配置
增加druid的配置
# 应用名称
spring.application.name=demo
# 应用服务 WEB 访问端口
server.port=8080
# 数据库设置
spring.datasource.driverClassName=oracle.jdbc.OracleDriver
spring.datasource.url=jdbc:oracle:thin:@192.168.0.100:1521:orcl
spring.datasource.username=zy
spring.datasource.password=1
# druid配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
# druid参数调优（可选）
# 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
# 测试连接
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
spring.datasource.filters=stat
# asyncInit是1.1.4中新增加的配置，如果有initialSize数量较多时，打开会加快应用启动时间
spring.datasource.asyncInit=true
注：必填项只有
# druid配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
4、数据库准备
oracle里创建表及初始化表 注：oralce中创建的用户为zy，密码为1 CREATE TABLE TEST_BLOCK_T ( BLOCK_ID VARCHAR2(10 BYTE) PRIMARY KEY, --编码 BLOCK_NAME VARCHAR2(200 BYTE) --资源名称 ); Insert into TEST_BLOCK_T (BLOCK_ID, BLOCK_NAME) Values ('1', 'java'); COMMIT;
5、DruidConfig.java配置
由于现在Spring Boot不支持druid配置，参数调优部分的配置不会直接生效，需要配置datasource bean，从application.properties中读取值来装配datasource bean，新增DruidConfig.java配置文件：
package com.example.demo.config; import java.sql.SQLException; import javax.sql.DataSource; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import com.alibaba.druid.pool.DruidDataSource; @Configuration public class DruidConfig { private Logger logger = LoggerFactory.getLogger(DruidConfig.class); @Value("${spring.datasource.url}") private String dbUrl; @Value("${spring.datasource.username}") private String username; @Value("${spring.datasource.password}") private String password; @Value("${spring.datasource.driver-class-name}") private String driverClassName; @Value("${spring.datasource.initial-size}") private int initialSize; @Value("${spring.datasource.min-idle}") private int minIdle; @Value("${spring.datasource.max-active}") private int maxActive; @Value("${spring.datasource.max-wait}") private int maxWait; @Value("${spring.datasource.time-between-eviction-runs-millis}") private int timeBetweenEvictionRunsMillis; @Value("${spring.datasource.min-evictable-idle-time-millis}") private int minEvictableIdleTimeMillis; @Value("${spring.datasource.test-while-idle}") private boolean testWhileIdle; @Value("${spring.datasource.test-on-borrow}") private boolean testOnBorrow; @Value("${spring.datasource.test-on-return}") private boolean testOnReturn; @Value("${spring.datasource.pool-prepared-statements}") private boolean poolPreparedStatements; @Value("${spring.datasource.max-pool-prepared-statement-per-connection-size}") private int maxPoolPreparedStatementPerConnectionSize; @Value("${spring.datasource.filters}") private String filters; @Bean //声明其为Bean实例 @Primary //在同样的DataSource中，首先使用被标注的DataSource public DataSource dataSource(){ DruidDataSource datasource = new DruidDataSource(); datasource.setUrl(this.dbUrl); datasource.setUsername(username); datasource.setPassword(password); datasource.setDriverClassName(driverClassName); //configuration datasource.setInitialSize(initialSize); datasource.setMinIdle(minIdle); datasource.setMaxActive(maxActive); datasource.setMaxWait(maxWait); datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis); datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis); datasource.setTestWhileIdle(testWhileIdle); datasource.setTestOnBorrow(testOnBorrow); datasource.setTestOnReturn(testOnReturn); datasource.setPoolPreparedStatements(poolPreparedStatements); datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize); try { datasource.setFilters(filters); } catch (SQLException e) { logger.error("druid configuration initialization filter", e); } return datasource; } }
package com.example.demo.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.web.bind.annotation.*; @RestController @RequestMapping("/hello") public class HelloController { @Autowired JdbcTemplate jdbcTemplate; @GetMapping("/list") @ResponseBody public String index() { String sql = "SELECT BLOCK_NAME FROM XY_DIC_BLOCK_T WHERE BLOCK_ID = ?"; // 通过jdbcTemplate查询数据库 String mobile = (String) jdbcTemplate.queryForObject( sql, new Object[]{1}, String.class); System.out.println("haha"); return "Hello " + mobile; } }
6、启动项目访问项目
到这看着和前一个项目没撒区别，继续往下看
7、druid的监控页面
浏览器输入http://localhost:8080/druid
就会发现连接池的监控页面（要先执行一下步骤5，要不监控页面没有内容，因为还没有连接数据自然就没有连接的信息了）