数据库
--用户表
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`account` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
`password` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT 'E10ADC3949BA59ABBE56E057F20F883E',
`propertyId` int(11) NOT NULL DEFAULT -1,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
--属性表
CREATE TABLE `property` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`uid` int(11) NOT NULL,
`key` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
`value` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
mybatis逆向工程
1.使用idea新建maven项目,pom内容如下:
<?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>top.changelife</groupId>
<artifactId>mybatis-generator</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.35</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.6</version>
<configuration>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
</plugin>
</plugins>
</build>
</project>
2.在src/main/resource目录下新建geoneratorConfig.xml文件,内容如下:
<?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>
<classPathEntry
location="C:/Users/35152/.m2/repository/mysql/mysql-connector-java/5.1.35/mysql-connector-java-5.1.35.jar"/>
<context id="mysqlTables">
<plugin type="org.mybatis.generator.plugins.SerializablePlugin"></plugin>
<plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin"></plugin>
<plugin type="org.mybatis.generator.plugins.ToStringPlugin"></plugin>
<commentGenerator>
<!-- 是否去除自动生成的注释 true:是 : false:否 -->
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<!--数据库连接的信息:驱动类、连接地址、用户名、密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/test" userId="root"
password="123456">
</jdbcConnection>
<!-- 默认false,把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer,为 true时把JDBC DECIMAL 和
NUMERIC 类型解析为java.math.BigDecimal -->
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- targetProject:生成PO类的位置 -->
<javaModelGenerator targetPackage="top.changelife.dynamicproperty.model"
targetProject="./src/main/java">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false"/>
<!-- 从数据库返回的值被清理前后的空格 -->
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- targetProject:mapper映射文件生成的位置 -->
<sqlMapGenerator targetPackage="top.changelife.dynamicproperty.mapper"
targetProject="./src/main/java">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false"/>
</sqlMapGenerator>
<!-- targetPackage:mapper接口生成的位置 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="top.changelife.dynamicproperty.dao"
targetProject="./src/main/java">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="false"/>
</javaClientGenerator>
<!-- 指定数据库表 -->
<table tableName="users" domainObjectName="Users" schema="public" enableCountByExample="false"
enableDeleteByExample="false" enableUpdateByExample="false"
enableSelectByExample="false" selectByExampleQueryId="false"></table>
</context>
</generatorConfiguration>
这里需要重点注意的不是数据库的连接信息的填写,这个用过jdbc的你想必是没有问题的,重点要关注的是classPathEntry
,不要以为在pom里面配置了连接mysql的jar包就万事大吉,这里一定要指定你电脑上jar包所在的绝对地址才行。
3.指定运行方式
工具栏Run
–>Edit Configurations
–>+
–>Maven
Command line : mybatis-generator:generate -e
设置完成后点OK
,然后就可以运行了。
新建springboot项目
使用idea新建springboot项目 File
–>New
–>Project
–>Spring Initializr
……这里比较简单,就不细说了。
在pom.xml中引入相关依赖:
<?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>top.changelife</groupId>
<artifactId>dynamic-property</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>dynamic-property</name>
<description>mysql实现动态属性配置</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/>
</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-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.35</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
我这里使用mybatis连接数据库,需要在application.properties中进行配置:
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?username=root
spring.datasource.username=root
spring.datasource.password=1314
mybatis.mapper-locations=classpath:mapper/*Mapper.xml
mybatis.config-location=classpath:mapper/config/sqlMapperConfig.xml
程序目录结构如下:
下面陆续贴出相关代码,如对springboot和mybatis不甚了解,可查阅相关资料。
sqlMapperConfig.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias alias="users" type="top.changelife.dynamicproperty.model.Users"/>
<typeAlias alias="property" type="top.changelife.dynamicproperty.model.Property"/>
</typeAliases>
</configuration>
PropertyMapper.xml
<?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="top.changelife.dynamicproperty.dao.PropertyMapper">
<insert id="insert" keyProperty="id" useGeneratedKeys="true" parameterType="java.util.List">
insert into property (uid, property.key,property.value) values
<foreach collection="list" item="property" separator=",">
(#{property.uid,jdbcType=INTEGER},
#{property.key,jdbcType=VARCHAR}, #{property.value,jdbcType=VARCHAR})
</foreach>
</insert>
</mapper>
UsersMapper.xml
<?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="top.changelife.dynamicproperty.dao.UsersMapper">
<resultMap id="UserResultMap" type="users">
<id property="id" column="id"/>
<result column="account" jdbcType="VARCHAR" property="account"/>
<result column="password" jdbcType="VARCHAR" property="password"/>
<result column="propertyId" jdbcType="INTEGER" property="propertyId"/>
<collection property="list" ofType="property">
<id column="property_id" jdbcType="INTEGER" property="id"/>
<result column="uid" jdbcType="INTEGER" property="uid"/>
<result column="key" jdbcType="VARCHAR" property="key"/>
<result column="value" jdbcType="VARCHAR" property="value"/>
</collection>
</resultMap>
<select id="selectAll" resultMap="UserResultMap">
SELECT
u.id AS id,u.account AS account,u.password AS PASSWORD,u.propertyId as propertyId,
p.id AS property_id,p.uid as uid,p.key AS 'key',p.value AS 'value'
FROM users u,property p WHERE u.propertyid = p.uid
</select>
<insert id="insert" keyProperty="id" useGeneratedKeys="true" parameterType="users">
insert into users (account, password, propertyId)
values (#{account,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR}, #{propertyId,jdbcType=INTEGER})
</insert>
</mapper>
Users
package top.changelife.dynamicproperty.model;
import java.io.Serializable;
import java.util.List;
public class Users implements Serializable {
private Integer id;
private String account;
private String password;
private Integer propertyId;
private List<Property> list;
private static final long serialVersionUID = 1L;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getAccount() {
return account;
}
public void setAccount(String account) {
this.account = account == null ? null : account.trim();
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password == null ? null : password.trim();
}
public Integer getPropertyId() {
return propertyId;
}
public void setPropertyId(Integer propertyId) {
this.propertyId = propertyId;
}
public List<Property> getList() {
return list;
}
public void setList(List<Property> list) {
this.list = list;
}
@Override
public boolean equals(Object that) {
if (this == that) {
return true;
}
if (that == null) {
return false;
}
if (getClass() != that.getClass()) {
return false;
}
Users other = (Users) that;
return (this.getId() == null ? other.getId() == null : this.getId().equals(other.getId()))
&& (this.getAccount() == null ? other.getAccount() == null : this.getAccount().equals(other.getAccount()))
&& (this.getPassword() == null ? other.getPassword() == null : this.getPassword().equals(other.getPassword()))
&& (this.getPropertyId() == null ? other.getPropertyId() == null : this.getPropertyId().equals(other.getPropertyId()));
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((getId() == null) ? 0 : getId().hashCode());
result = prime * result + ((getAccount() == null) ? 0 : getAccount().hashCode());
result = prime * result + ((getPassword() == null) ? 0 : getPassword().hashCode());
result = prime * result + ((getPropertyId() == null) ? 0 : getPropertyId().hashCode());
return result;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(getClass().getSimpleName());
sb.append(" [");
sb.append("Hash = ").append(hashCode());
sb.append(", id=").append(id);
sb.append(", account=").append(account);
sb.append(", password=").append(password);
sb.append(", propertyid=").append(propertyId);
sb.append(", list=").append(list);
sb.append(", serialVersionUID=").append(serialVersionUID);
sb.append("]");
return sb.toString();
}
}
Property
package top.changelife.dynamicproperty.model;
import java.io.Serializable;
public class Property implements Serializable {
private Integer id;
private Integer uid;
private String key;
private String value;
private static final long serialVersionUID = 1L;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key == null ? null : key.trim();
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value == null ? null : value.trim();
}
@Override
public boolean equals(Object that) {
if (this == that) {
return true;
}
if (that == null) {
return false;
}
if (getClass() != that.getClass()) {
return false;
}
Property other = (Property) that;
return (this.getId() == null ? other.getId() == null : this.getId().equals(other.getId()))
&& (this.getUid() == null ? other.getUid() == null : this.getUid().equals(other.getUid()))
&& (this.getKey() == null ? other.getKey() == null : this.getKey().equals(other.getKey()))
&& (this.getValue() == null ? other.getValue() == null : this.getValue().equals(other.getValue()));
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((getId() == null) ? 0 : getId().hashCode());
result = prime * result + ((getUid() == null) ? 0 : getUid().hashCode());
result = prime * result + ((getKey() == null) ? 0 : getKey().hashCode());
result = prime * result + ((getValue() == null) ? 0 : getValue().hashCode());
return result;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(getClass().getSimpleName());
sb.append(" [");
sb.append("Hash = ").append(hashCode());
sb.append(", id=").append(id);
sb.append(", uid=").append(uid);
sb.append(", key=").append(key);
sb.append(", value=").append(value);
sb.append(", serialVersionUID=").append(serialVersionUID);
sb.append("]");
return sb.toString();
}
}
UserController
package top.changelife.dynamicproperty.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import top.changelife.dynamicproperty.dao.PropertyMapper;
import top.changelife.dynamicproperty.dao.UsersMapper;
import top.changelife.dynamicproperty.model.Property;
import top.changelife.dynamicproperty.model.Users;
import java.util.List;
@RestController
public class UserController {
@Autowired
UsersMapper usersMapper;
@Autowired
PropertyMapper propertyMapper;
@GetMapping("/users")
public Object selectAllUsers() {
return usersMapper.selectAll();
}
@PostMapping("/users")
public Object insertUsers(@RequestBody Users user) {
List<Property> list = user.getList();
// System.out.println(list);
propertyMapper.insert(list);
usersMapper.insert(user);
return user;
}
}
代码就这么多,下面启动项目进行测试,我这里使用Postman进行接口测试。
前段可以随意增添list中的属性个数,达到动态增添字段的效果。
这里做得比较简单,实际使用中可以另建一张表,用来存储必备的字段,每次新增的时候都将必备的字段取出来让用户填写,然后其他的再自定义。
遇到的问题
在写这个demo以前,思路是很清晰的,没想到还是遇到不少的问题,首先就是application.properties中配置数据库出错,spring.datasource.username
写错了,导致数据库连接获取不到,报错却为Access denied for user ''@'localhost'
,找了很久才发现原来是自己粗心导致。
还有就是无论何时,定义了带参数的构造函数,一定要将无参构造函数写上,免得后期出错。
总结
以上为个人经验,希望能给大家一个参考,也希望大家多多支持编程网。