springboot项目案例
ideal 连接mysql
通过前后端的一个搭建可以让我们更好的掌握全栈开发的一个基础,这也是众多项目的一个开始
准备工作
- jdk17
- 项目语言17
- maven
- mysql
- apcha
** 首先创建一个springboot项目 ,这里组件也就是项目的目录结构 选择方式为maven。后续的springboot不再支持jdk8,所以这里运用的版本为17,如果想用jdk8的话记得在版本中选择2.6.7 ,然后打包的方式为jar包 **
** 接下来就是添加依赖 这里我们需要引用两个依赖一个web,另一个就是mysql,我们先实现这个最基本的效果**
再新建一个helloController的Java文件,用于编写hello请求的响应方法
此时就已经有了主启动文件Demo0305Application和控制文件helloController
接下来就开始编辑helloController文件
具体代码如下
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
class helloController {
@GetMapping("/hello")
public String hello(){
return "hello Spring Boot";
}
}
这个时候测试一下这个端口后缀为hello

接下来开始整合jdbc 实现Mysql的显示 下面是一些统配的依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!--Spring boot 核心-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!--Mysql依赖包-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- druid数据源驱动 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.6</version>
</dependency>
<dependency>
<groupId>org.lionsoul</groupId>
<artifactId>ip2region</artifactId>
<version>1.7.2</version>
</dependency>
</dependencies>
接下来开始配置 application.yml 这个位于静态资源的下方
spring:
datasource:
url: jdbc:mysql://localhost:3306/<数据库名字>? useUnicode=true&characterEncoding=utf8
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
这时,MySQL就链接好了,开始建立查询,我们重新写一个Controller,就命名为jdbcController,创建方法和helloController的方法一

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.Map;
import java.util.List;
@RestController
public class jdbcController {
@Autowired
JdbcTemplate jdbcTemplate;
//写一个list请求,查询数据库信息
@GetMapping("/list")
public List<Map<String,Object>> list(){
String sql="select * from <表名>";
List<Map<String,Object>> list_map=jdbcTemplate.queryForList(sql);
return list_map;
}
}
有一个 @Autowired的注解,这里也是自动注入的注解,还有一条我们熟悉的 @GetMapping注解,list里面包含了一条sql语句,具体语句是写在双引号里面并进行赋值的,使用List<Map<String,Object>> list_map=jdbcTemplate.queryForList(sql);方法将查询到的信息罗列出来,并进行返回到主页的操作。
原文链接:https://blog.csdn.net/English221/article/details/129347883
一整合druid
首先先说一下druid是阿里巴巴旗下的一个开源框架,能够通过数据库连接池,结合c3p0,DBCP,从而实现对数据库的监控功能
这里要用到的jdk为1.8 添加的依赖为 jdbc mysqlDriver web
druid依赖
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.21</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.kuang</groupId>
<artifactId>springboot-04-data</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot-04-data</name>
<description>springboot-04-data</description>
<url/>
<licenses>
<license/>
</licenses>
<developers>
<developer/>
</developers>
<scm>
<connection/>
<developerConnection/>
<tag/>
<url/>
</scm>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.21</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<version>8.0.32</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
applicaton.yml
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://localhost:3306/mao?useUnicode=true&characterEncoding=utf-8
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
#SpringBoot默认是不注入这些的,需要自己绑定
#druid数据源专有配置
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
#配置监控统计拦截的filters,stat:监控统计、log4j:日志记录、wall:防御sql注入
#如果允许报错,java.lang.ClassNotFoundException: org.apache.Log4j.Properity
#则导入log4j 依赖就行
filters: stat,wall,log4j
maxPoolPreparedStatementPerConnectionSize: 20
useGlobalDataSourceStat: true
connectionoProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
在controller下创建config目录,并在其下创建DruidConfig
package com.kuang.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.sql.DataSource;
import java.util.HashMap;
@Configuration
public class DruidConfig {
@ConfigurationProperties(prefix = "spring.datasource")
@Bean
public DataSource druiddataSource(){
return new DruidDataSource();
}
// 后台监控
@Bean
public ServletRegistrationBean statViewServlet(){
ServletRegistrationBean<StatViewServlet> bean =
new ServletRegistrationBean<>(new StatViewServlet(), "/druid/*");
// 后台需要有人登录,账号密码配置
HashMap<String,String> initParameters = new HashMap<>();
// 增加配置
initParameters.put("loginUsername","admin");
initParameters.put("loginPassword","123456");
bean.setInitParameters(initParameters);
// 设置初始化
return bean;
}
}

一整合mybatis
导入mybatis依赖
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.3.1</version>
</dependency>





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