利用IDEA搭建SpringBoot项目,整合mybatis,实现简单的登录功能。
仅供参考!!!
仅供参考!!!
仅供参考!!!
利用闲余时间想自己搭建一个springboot+mybatis的项目,提升一下自己对项目的了解,毕竟自己还是一个小白,在这里为自己创建项目的过程做一个记录,以便以后回忆。同时将搭建中遇到的问题也在这里做记录。如有遇到同样问题的同学,希望能给你一下借鉴。
springboot的优势之一就是快速搭建项目,省去了自己导入jar包和配置xml的时间,使用非常方便。
一,搭建项目:
1、打开IDEA,点击File→New→Project...,如图1所示
图1 搭建项目
2、当我们选择project...后,会看见如图2所示的页面,选择Spring Initializr,点击NEXT即可。
图2 搭建项目
3、接下来将看到如图3所示的页面,在这个页面中我只是修改了名称。然后点击NEXT进行下一步。
图3 搭建项目
4、当我点击NEXT时,却出现如图4所示的错误,这由于创建时因为Artifact的命名为大小写混合,将大写改为小写即可正常创建。
图4 搭建项目 (注意名称大小写问题)
5、接下来我们修改上面的错误,我将springbootTest1→springboottest1,然后进行下一步。会看见如图5所示的页面。 在当前页面中我们一次选择左侧的Web、Template Engines、SQL。然后在中间部分选择我们需要的选项,最终选择结果如最右侧所示。然后点击NEXT,进行下一步。
图5 搭建项目(选择需要的内容)
6、如图6所示,进人创建项目的最后一个页面,在这里我们可以修改项目保存的位置。确认自己输入的内容,点击Fiish即可完成项目的创建。
图6 搭建项目(可以修改文件路径)
7、点击Finish后,出现如图7所示页面,我们选择New Window即可,即在新的IDEA中打开我们新建的项目。
图7 打开项目
二、启动项目、添加配置文件等
1、打开新项目后,我们可以观察一下左侧的项目结构。如图8所示。
生成的项目中,resources文件夹下,static文件夹下存放静态文件,比如css、js、html和图片等 。
templates下存放html文件,controller默认访问该文件夹下的html文件。
这个在application.properties配置文件中是可以修改的。
下面为项目生成的pom.xml文件:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>springboottest1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboottest1</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</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-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<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>
图8 项目文件结构
2、了解项目的文件结构后,我们尝试着启动项目。我们发现项目启动过程中出现错误,错误信息如图9所示。
图9 项目启动报错
这是因为我们创建Spring Boot项目时,在选择组件时添加了mysql、mybatis,但现在还没有配置数据库,导致项目启动报错。
我们需要在项目的application.properties文件中配置数据信息。如图10所示,是我自己配置的数据库,具体情况根据自己数据库的设置配置。
图10 数据库配置
数据库采用MySQL数据库,下面是数据库的设计,只有几个简单的字段。如图11所示。
图11 数据库设计
这里也可以不使用application.properties文件,采用更加简洁的application.yml文件。将resource文件夹下原有的application.properties文件删除,创建application.yml配置文件(备注:其实SpringBoot底层会把application.yml文件解析为application.properties), 文件的内容如下(此处只配置最基本的):
server:
port: 8080
spring:
datasource:
name: test
url: jdbc:mysql://127.0.0.1:3306/test
username: root
password: 123456
driver-class-name: com.mysql.jdbc.Driver
接下来再次尝试重新启动项目。发现项目可以正常启动了。可以打开浏览器访问http://localhost:8080/,访问结果如图12所示。证明项目正常启动了。
图12 访问结果
三、项目整合mybatis
1、在application.yml文件中添加mybatis。
server:
port: 8080
spring:
datasource:
name: test
url: jdbc:mysql://127.0.0.1:3306/test
username: root
password: 123456
driver-class-name: com.mysql.jdbc.Driver
mybatis:
mapper-locations: classpath:mapper/*.xml #注意:一定要对应mapper映射xml文件的所在路径
type-aliases-package: com.example.springboottest1.entity # 注意:对应实体类的路径
2、在pom.xml中添加 mybatis generator 自动生成代码插件。
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- mybatis generator 自动生成代码插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.1</version>
<configuration>
<configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
</plugin>
</plugins>
</build>
3、在resource文件夹下创建generator文件夹,并在文件夹中创建generatorConfig.xml文件。文件内容如下所示:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
<classPathEntry location="C:\Program Files (x86)\MySQL\Connector.J 5.1\mysql-connector-java-5.1.36-bin.jar"/>
<context id="DB2Tables" targetRuntime="MyBatis3">
<commentGenerator>
<property name="suppressDate" value="true"/>
<!-- 是否去除自动生成的注释 true:是 : false:否 -->
<property name="suppressAllComments" value="false"/>
</commentGenerator>
<!--数据库连接驱动类,URL,用户名、密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/test" userId="root" password="123456">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- 生成(实体)模型的包名和位置-->
<javaModelGenerator targetPackage="com.example.springboottest1.entity" targetProject="src">
<property name="enableSubPackages" value="true"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- 生成XML映射文件的包名和位置-->
<sqlMapGenerator targetPackage="resources.mapper" targetProject="src">
<property name="enableSubPackages" value="true"/>
</sqlMapGenerator>
<!-- 生成DAO接口的包名和位置-->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.example.springboottest1.mapper" targetProject="src">
<property name="enableSubPackages" value="true"/>
</javaClientGenerator>
<!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
<table tableName="user" domainObjectName="user" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
</context>
</generatorConfiguration>
4、所有文件创建完成后,还需要进行简单的配置。Run→Edit Configurations...,然后选择maven,配置Command line。
5、所用文件创建完成,并配置好相关设置,重新启动项目,启动后运行generator。通过控制台可以看见代码是否生成成功,或失败的原因。如果代码生成成功,可以在项目文件夹中看见生成的项目。
这个过程共生成三个文件,一个实体类,dao,还有sql语句。
5.1、生成的实体类entity:
package com.example.springboottest1.entity;
public class user {
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user.id
*
* @mbggenerated
*/
private Integer id;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user.username
*
* @mbggenerated
*/
private String username;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user.password
*
* @mbggenerated
*/
private String password;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user.age
*
* @mbggenerated
*/
private Integer age;
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user.id
*
* @return the value of user.id
*
* @mbggenerated
*/
public Integer getId() {
return id;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user.id
*
* @param id the value for user.id
*
* @mbggenerated
*/
public void setId(Integer id) {
this.id = id;
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user.username
*
* @return the value of user.username
*
* @mbggenerated
*/
public String getUsername() {
return username;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user.username
*
* @param username the value for user.username
*
* @mbggenerated
*/
public void setUsername(String username) {
this.username = username == null ? null : username.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user.password
*
* @return the value of user.password
*
* @mbggenerated
*/
public String getPassword() {
return password;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user.password
*
* @param password the value for user.password
*
* @mbggenerated
*/
public void setPassword(String password) {
this.password = password == null ? null : password.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user.age
*
* @return the value of user.age
*
* @mbggenerated
*/
public Integer getAge() {
return age;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user.age
*
* @param age the value for user.age
*
* @mbggenerated
*/
public void setAge(Integer age) {
this.age = age;
}
}
5.2、生成的Dao:
package com.example.springboottest1.mapper;
import com.example.springboottest1.entity.user;
public interface userMapper {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int deleteByPrimaryKey(Integer id);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int insert(user record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int insertSelective(user record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
user selectByPrimaryKey(Integer id);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int updateByPrimaryKeySelective(user record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int updateByPrimaryKey(user record);
}
5.3、生成的SQL语句(其中一些没有用的注释被我删掉了):
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.example.springboottest1.mapper.userMapper" >
<resultMap id="BaseResultMap" type="com.example.springboottest1.entity.user" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
<id column="id" property="id" jdbcType="INTEGER" />
<result column="username" property="username" jdbcType="VARCHAR" />
<result column="password" property="password" jdbcType="VARCHAR" />
<result column="age" property="age" jdbcType="INTEGER" />
</resultMap>
<sql id="Base_Column_List" >
id,
username,
password,
age
</sql>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
select
<include refid="Base_Column_List" />
from user
where id = #{id,jdbcType=INTEGER}
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
delete from user
where id = #{id,jdbcType=INTEGER}
</delete>
<insert id="insert" parameterType="com.example.springboottest1.entity.user" >
insert into user (id, username, password, age)
values (
#{id,jdbcType=INTEGER},
#{username,jdbcType=VARCHAR},
#{password,jdbcType=VARCHAR},
#{age,jdbcType=INTEGER})
</insert>
<insert id="insertSelective" parameterType="com.example.springboottest1.entity.user" >
insert into user
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="id != null" >
id,
</if>
<if test="username != null" >
username,
</if>
<if test="password != null" >
password,
</if>
<if test="age != null" >
age,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="id != null" >
#{id,jdbcType=INTEGER},
</if>
<if test="username != null" >
#{username,jdbcType=VARCHAR},
</if>
<if test="password != null" >
#{password,jdbcType=VARCHAR},
</if>
<if test="age != null" >
#{age,jdbcType=INTEGER},
</if>
</trim>
</insert>
<update id="updateByPrimaryKeySelective" parameterType="com.example.springboottest1.entity.user" >
update user
<set >
<if test="username != null" >
username = #{username,jdbcType=VARCHAR},
</if>
<if test="password != null" >
password = #{password,jdbcType=VARCHAR},
</if>
<if test="age != null" >
age = #{age,jdbcType=INTEGER},
</if>
</set>
where id = #{id,jdbcType=INTEGER}
</update>
<update id="updateByPrimaryKey" parameterType="com.example.springboottest1.entity.user" >
update user
set username = #{username,jdbcType=VARCHAR},
password = #{password,jdbcType=VARCHAR},
age = #{age,jdbcType=INTEGER}
where id = #{id,jdbcType=INTEGER}
</update>
</mapper>
四、测试访问
做好以上的准备以后,可以简单的写一个小页面,试着访问一下。
同时这个时候可以自己了解一下@Controller与@RestController的区别,以及@ResponseBody的用法。
1、比如写一个简单的HTML页面,HelloWord.html。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>HelloWord</title>
</head>
<body>
<h1>hello springboot!!!</h1>
</body>
</html>