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>
posted @ 2025-04-22 21:58  白鹿为溪  阅读(50)  评论(0)    收藏  举报