Java Config 之 SSM搭建(Mybatis-Plus)

1.JavaConfig概念

　　a.定义：Spring JavaConfig 是Spring社区的产品，它提供了配置Spring IOC容器的纯Java方法。因此它有助于避免使用XML配置

　　b.常用注解：

　　　　1）@Configuration：在类上打上这一标签，表示这个类是配置类，即表示该类为spring-*.xml

　　　　2）@ComponentScan：扫描包，相当于 <context:component-scan base-package="包路径"/>

　　　　3）@Bean：定义Bean，相当于 <bean id="类ID" class="全类名" />

　　　　4）@EnableWebMvc：开启MVC注解，相当于 <mvc:annotation-driven/>

　　　　5）@ImportResource：导入xml配置文件，相当于 <import resource="classpath:spring-mybatis.xml" />

　　　　6）@Import：导入其他 @Configuration 配置类

　　　　7）@PropertySource：读取properties文件，配合 @Value 使用

　　　　8）@EnableTransactionManagement：开启事务，相当于 <tx:annotation-driven/>

2.后端搭建

　　a.在数据库创建`t_user`用户表

-- 用户表
CREATE TABLE `t_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(255) NOT NULL,
  `user_pwd` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
);

　　b.导入Maven依赖

  <properties>

    ......

    <!-- spring -->
    <spring.version>5.1.1.RELEASE</spring.version>
    <!-- jackson-json -->
    <jackson.version>2.9.4</jackson.version>
    <!-- log4j -->
    <slf4j.version>1.7.18</slf4j.version>
    <log4j.version>1.2.17</log4j.version>
  </properties>

  <dependencies>
    <!-- spring -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-oxm</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!-- Jackson -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>${jackson.version}</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>${jackson.version}</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>${jackson.version}</version>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>

    <!-- AOP -->
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjrt</artifactId>
      <version>1.8.6</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.8.6</version>
    </dependency>

    <!-- 日志相关 -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>${log4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>${slf4j.version}</version>
    </dependency>

    <!-- spring-jdbc -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- MySQL -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.13</version>
    </dependency>
    <!-- 连接池 -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.12</version>
    </dependency>

    <!-- mp 依赖 -->
    <dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus</artifactId>
      <version>3.2.0</version>
    </dependency>

    <!-- servlet -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>

　　c.创建jdbc.properties配置文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mytest?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
jdbc.username=root
jdbc.password=123456

　　d.创建web配置类（对应web.xml）

public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected String[] getServletMappings() {
        return new String[] { "/" };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[] { MvcConfig.class };
    }

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[] { RootConfig.class };
    }

}

　　e.创建Spring配置类（对应spring.xml）

@Configuration
@ComponentScan("com.wode")
@EnableTransactionManagement //开启事务支持
@Import(DataBaseConfig.class)//导入数据源的配置
public class RootConfig {
}

　　f.创建DB配置类（对应spring-mybatis.xml）

@Configuration
@PropertySource("classpath:jdbc.properties")
public class DataBaseConfig {

    @Value("${jdbc.driver}")
    private String driver;

    @Value("${jdbc.url}")
    private String url;

    @Value("${jdbc.username}")
    private String username;

    @Value("${jdbc.password}")
    private String password;


    // 创建数据源
    @Bean
    public DruidDataSource dataSource(){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

    // 创建全局配置
    @Bean
    public GlobalConfig globalConfig() {
        GlobalConfig globalConfig = new GlobalConfig();
        GlobalConfig.DbConfig dbConfig = new GlobalConfig.DbConfig();
        // 默认为自增
        dbConfig.setIdType(IdType.AUTO);
        // 全局的表前缀策略配置
        dbConfig.setTablePrefix("t_");
        globalConfig.setDbConfig(dbConfig);
        return globalConfig;
    }

    @Bean
    public MybatisSqlSessionFactoryBean sqlSessionFactory(DruidDataSource dataSource, GlobalConfig globalConfig) {
        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        //加载数据源
        sqlSessionFactoryBean.setDataSource(dataSource);
        //加载 mybatis-plus 全局属性
        sqlSessionFactoryBean.setGlobalConfig(globalConfig);
        //指定 pojo 目录
        sqlSessionFactoryBean.setTypeAliasesPackage("com.wode.entity");
        //mybatis-plus 插件(分页插件)
        Interceptor[] interceptors = {new PaginationInterceptor()};
        sqlSessionFactoryBean.setPlugins(interceptors);
        return sqlSessionFactoryBean;
    }

    @Bean
    public static MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer configurer = new MapperScannerConfigurer();
        configurer.setBasePackage("com.wode.dao");
        // 设置为上面的 factory name
        configurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
        return configurer;
    }

    //事务管理器
    @Bean
    public DataSourceTransactionManager transactionManager(DruidDataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

　　注意：如果 mapperScannerConfigurer 不加 static，会导致整个都提前加载，这时候取不到 @Value 的值。

　　g.创建MVC配置类（对应spring-mvc.xml）

@Configuration
@EnableWebMvc
@ComponentScan("com.wode.controller")
public class MvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/home").setViewName("/home");
        registry.addViewController("/detail").setViewName("/detail");
        super.addViewControllers(registry);
    }

    //配置jsp视图
    @Bean
    public ViewResolver viewResolver(){
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/page");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    //配置静态资源处理
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();//将静态资源的请求转发到servlet容器中默认的servlet上
    }

}

　　h.创建entity实体类

@TableName
//@TableName("t_user")
public class User {

    @TableId
    private Integer id;
    private String userName;
    private String userPwd;

    public User(){}

    public User(Integer id, String userName, String userPwd) {
        this.id = id;
        this.userName = userName;
        this.userPwd = userPwd;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPwd() {
        return userPwd;
    }

    public void setUserPwd(String userPwd) {
        this.userPwd = userPwd;
    }

}

　　i.创建Dao

public interface UserMapper extends BaseMapper<User> {
}

　　j.创建Service

@Service
public class UserService {

    @Resource
    private UserMapper userMapper;

    public boolean addUser(User user){
        if(userMapper.insert(user) > 0){
            return true;
        }
        return false;
    }

    public boolean updateUser(User user){
        if(userMapper.updateById(user) > 0){
            return true;
        }
        return false;
    }

    public User getUser(int id){
        return userMapper.selectById(id);
    }

    public IPage<User> getUserList(int currentPage, int pageSize){
        Page<User> page = new Page<>(currentPage, pageSize);
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        return userMapper.selectPage(page, queryWrapper);
    }

    public boolean deleteUser(int id){
        if(userMapper.deleteById(id) > 0){
            return true;
        }
        return false;
    }

}

　　k.创建Controller

@RestController
@RequestMapping("/user")
public class UserController {

    @Resource
    private UserService userService;

    @PostMapping("/add")
    public String addUser(User user) {
        if(userService.addUser(user)){
            return "Success";
        }
        return "Failure";
    }

    @PostMapping("/update")
    public String updateUser(User user) {
        if(userService.updateUser(user)){
            return "Success";
        }
        return "Failure";
    }

    @RequestMapping("/get/{id}")
    public User getUser(@PathVariable("id") int id) {
        return userService.getUser(id);
    }

    @RequestMapping("/list")
    public IPage<User> getUserList(int currentPage, int pageSize){
        return userService.getUserList(currentPage, pageSize);
    }

    @RequestMapping("/delete/{id}")
    public String deleteUser(@PathVariable("id") int id){
        if(userService.deleteUser(id)){
            return "Success";
        }
        return "Failure";
    }

}

3.前端测试

　　a.在 webapp/WEB-INF/page 目录下创建 home.jsp 和 detail.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html lang="en">
<head>
    <base href="<%=basePath%>">
    <meta charset="UTF-8">
    <title>首页</title>
    <link rel="stylesheet" href="css/common.css"/>
</head>
<body>
<div>
    <h1>首页</h1>
    <div class="row">
        <table id="list-table" border="1">
            <tr>
                <th>编号</th>
                <th>账号</th>
                <th>密码</th>
                <th>操作</th>
            </tr>
        </table>
    </div>
    <div class="row">
        <div class="col">
            <button id="list-btn">用户列表</button>
        </div>
        <div class="col">
            <button id="add-btn">添加用户</button>
        </div>
    </div>
</div>
</body>
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script src="js/home.js"></script>
</html>

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html lang="en">
<head>
    <base href="<%=basePath%>">
    <meta charset="UTF-8">
    <title>保存</title>
    <link rel="stylesheet" href="css/common.css"/>
</head>
<body>
<div>
    <h1>保存</h1>
    <div class="row">
        <div class="col">
            <label>用户名：</label><input id="username-input" type="text"/>
        </div>
    </div>
    <div class="row">
        <div class="col">
            <label>密码：</label><input id="userpwd-input" type="text"/>
        </div>
    </div>
    <div class="row">
        <div class="col">
            <button id="save-btn">保存</button>
        </div>
        <div class="col">
            <button id="close-btn">关闭</button>
        </div>
    </div>
    <input id="id" type="hidden" value="${param.id}" />
</div>
</body>
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script src="js/detail.js"></script>
</html>

　　b.在 webapp/css 下创建 common.css

.row{
    margin:10px 0px;
}

.col{
    display: inline-block;
    margin:0px 5px;
}

　　c.在 webapp/js 下创建 home.js 和 detail.js

$(function() {
    //获取用户列表
    $("#list-btn").on("click", getUserListFunc);

    //用户详情
    $(document).on("click", ".detail-btn",function(){
        let id = $(this).attr('data-id');
        location.href = "detail?id=" + id;
    });

    //删除用户
    $(document).on("click", ".delete-btn",function(){
        let id = $(this).attr('data-id');
        $.ajax({
            url: "user/delete/" + id,
            success: function(data){
                alert("删除成功！");
                getUserListFunc();
            },
            error: function(e){
                alert("系统错误！");
            },
        })
    });

    //添加用户
    $("#add-btn").on("click",function(){
        location.href = "detail";
    });

});

//函数：获取用户列表
let getUserListFunc = function() {
    $.ajax({
        url: "user/list",
        data: {
            currentPage: 1,
            pageSize: 100
        },
        success: function (data) {
            if (data) {
                $("#list-table").empty();
                $("#list-table").html("<tr><th>编号</th><th>账号</th><th>密码</th><th>操作</th></tr>");
                let userArray = data.records;
                for (let i in userArray) {
                    let user = userArray[i];
                    let id = user.id;
                    let userName = user.userName;
                    let userPwd = user.userPwd
                    let trTemplate = `<tr>
                                    <th>${id}</th>
                                    <th>${userName}</th>
                                    <th>${userPwd}</th>
                                    <th>
                                        <button class="detail-btn" data-id="${id}">详情</button>
                                        <button class="delete-btn" data-id="${id}">删除</button>
                                    </th>
                                </tr>`;
                    $("#list-table").append(trTemplate);
                }
            }
        },
        error: function (e) {
            console.log("系统错误！");
        },
    })
}

$(function() {
    //加载
    let id = $("#id").val();
    if(id){
        $.ajax({
            url: "user/get/" + id,
            success: function(data){
                if(data){
                    let userName = data.userName;
                    let userPwd = data.userPwd;
                    $("#username-input").val(userName);
                    $("#userpwd-input").val(userPwd);
                }else{
                    alert("系统错误！");
                }
            },
            error: function(e){
                alert("系统错误！");
            },
        })
    }

    //获取用户列表
    $("#save-btn").on("click",function(){
        let userName = $("#username-input").val();
        if(! userName){
            alert("用户名不能为空");
            return;
        }
        let userPwd = $("#userpwd-input").val();
        if(! userPwd){
            alert("密码不能为空");
            return;
        }
        let user;
        let url;
        //修改
        if(id){
            url = "user/update";
            user = {
                userName: userName,
                userPwd: userPwd,
                id: id
            };
            //添加
        }else{
            url = "user/add";
            user = {
                userName: userName,
                userPwd: userPwd
            };
        }
        $.ajax({
            url: url,
            type: "POST",
            data: user,
            success: function(data){
                alert("保存成功！");
            },
            error: function(e){
                alert("系统错误！");
            },
        })
    });

    //添加用户
    $("#close-btn").on("click",function(){
        location.href = "home";
    });

});

　　

　　d.访问 http://localhost:8080/项目名/home 测试

4.参考文章

　　https://blog.csdn.net/albenxie/article/details/82633775

　　https://www.cnblogs.com/hhhshct/p/9688079.html

　　https://www.cnblogs.com/saber-himesama/p/7478159.html

　　https://www.cnblogs.com/hinsy/p/9668684.html