4、SpringBoot连接数据库引入druid

系列导航

springBoot项目打jar包

1、springboot工程新建（单模块）

2、springboot创建多模块工程

3、springboot连接数据库

4、SpringBoot连接数据库引入druid

5、SpringBoot连接数据库引入mybatis

6、SpringBoot-mybatis分页实现pagehelper

7、SpringBoot-mybatis-plus引入

8、SpringBoot 事务

9、SpringBoot-mybatis-druid多源数据多源数据

10、SpringBoot-mybatis-plus-druid多源数据

11、SpringBoot-mybatis-plus-druid多源数据事务

12、SpringBoot-mybatis-plus-ehcache

13、SpringBoot-配置文件里密码加密

14、SpringBoot-easyexcel导出excle

完结

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 1、springboot工程新建（单模块）

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>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.1.17.RELEASE</spring-boot.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.2.0.3</version>
        </dependency>

        <!-- 集成druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.1.17.RELEASE</version>
                <configuration>
                    <mainClass>com.example.demo.DemoApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </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）