Java - SSM 整合案例

2024-06-06 本文已影响0人 Du1in9

👉 在线笔记：https://du1in9.github.io/ssm_demo.github.io/

1 SSM 整合

1.1 整合配置

Spring：Springconfig

@Configuration
@ComponentScan({"com.itheima.service"})
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class,MyBatisConfig.class})
@EnableTransactionManagement // 开启注解式事务驱动
public class SpringConfig {
}

SpringMVC：Servletconfig、SpringMvcConfig

public class ServletConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{SpringConfig.class};
    }
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{SpringMvcConfig.class};
    }
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        filter.setEncoding("UTF-8");
        return new Filter[]{filter};
    }
}

@Configuration
@ComponentScan("com.itheima.controller")
@EnableWebMvc
public class SpringMvcConfig {
}

MyBatis：MybatisConfig、Jdbcconfig、jdbc.properties

public class MyBatisConfig {
    @Bean
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSource);
        factoryBean.setTypeAliasesPackage("com.itheima.domain");
        return factoryBean;
    }

    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        MapperScannerConfigurer msc = new MapperScannerConfigurer();
        msc.setBasePackage("com.itheima.dao");
        return msc;
    }
}

public class JdbcConfig {
    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;

    @Bean
    public DataSource dataSource(){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean        // 设置事务管理器
    public PlatformTransactionManager transactionManager(DataSource dataSource){
        DataSourceTransactionManager ds = new DataSourceTransactionManager();
        ds.setDataSource(dataSource);
        return ds;
    }
}

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm_db?useSSL=false
jdbc.username=root
jdbc.password=123456

1.2 功能模块

表与实体类

CREATE TABLE `tbl_book`  (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `type` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
    `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
    `description` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
    PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 13 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

insert into `tbl_book`(`id`, `type`, `name`, `description`)
values (1, '计算机理论', 'Spring实战 第五版', 'Spring入门经典教程，深入理解Spring原理技术内幕'),
       (2, '计算机理论', 'Spring 5核心原理与30个类手写实践', '十年沉淀之作，手写Spring精华思想'),
       (3, '计算机理论', 'Spring 5设计模式', '深入Spring源码刨析Spring源码中蕴含的10大设计模式'),
       (4, '计算机理论', 'Spring MVC+Mybatis开发从入门到项目实战', '全方位解析面向Web应用的轻量级框架'),
       (5, '计算机理论', '轻量级Java Web企业应用实战', '源码级刨析Spring框架，适合已掌握Java基础的读者'),
       (6, '计算机理论', 'Java核心技术 卷Ⅰ 基础知识(原书第11版)', 'Core Java第11版，Jolt大奖获奖作品'),
       (7, '计算机理论', '深入理解Java虚拟机', '5个纬度全面刨析JVM,大厂面试知识点全覆盖'),
       (8, '计算机理论', 'Java编程思想(第4版)', 'Java学习必读经典，殿堂级著作！赢得了全球程序员的广泛赞誉'),
       (9, '计算机理论', '零基础学Java(全彩版)', '零基础自学编程的入门图书，由浅入深，详解Java语言的编程思想'),
       (10, '市场营销', '直播就这么做:主播高效沟通实战指南', '李子柒、李佳奇、薇娅成长为网红的秘密都在书中'),
       (11, '市场营销', '直播销讲实战一本通', '和秋叶一起学系列网络营销书籍'),
       (12, '市场营销', '直播带货:淘宝、天猫直播从新手到高手', '一本教你如何玩转直播的书，10堂课轻松实现带货月入3W+');

@Data
public class Book {
    private Integer id;
    private String type;
    private String name;
    private String description;
}

dao（数据层）：接口+自动代理

public interface BookDao {
    @Insert("insert into tbl_book (type,name,description) values(#{type},#{name},#{description})")
    public void save(Book book);

    @Update("update tbl_book set type=#{type}, name=#{name}, description=#{description} where id=#{id}")
    public void update(Book book);

    @Delete("delete from tbl_book where id = #{id}")
    public void delete(Integer id);

    @Select("select * from tbl_book where id = #{id}")
    public Book getById(Integer id);

    @Select("select * from tbl_book")
    public List<Book> getAll();
}

service（业务层）：接口+实现类

@Transactional   // 添加 Spring 事务管理
public interface BookService {
    public boolean save(Book book);

    public boolean update(Book book);

    public boolean delete(Integer id);

    public Book getById(Integer id);

    public List<Book> getAll();
}

@Service
public class BookServiceImpl implements BookService {
    @Autowired
    private BookDao bookDao;

    public boolean save(Book book) {
        bookDao.save(book);
        return true;
    }
    public boolean update(Book book) {
        bookDao.update(book);
        return true;
    }
    public boolean delete(Integer id) {
        bookDao.delete(id);
        return true;
    }
    public Book getById(Integer id) {
        return bookDao.getById(id);
    }
    public List<Book> getAll() {
        return bookDao.getAll();
    }
}

controller（表现层）

@RestController
@RequestMapping("/books")
public class BookController {
    @Autowired
    private BookService bookService;

    @PostMapping
    public boolean save(@RequestBody Book book) {
        return bookService.save(book);
    }
    @PutMapping
    public boolean update(@RequestBody Book book) {
        return bookService.update(book);
    }
    @DeleteMapping("/{id}")
    public boolean delete(@PathVariable Integer id) {
        return bookService.delete(id);
    }
    @GetMapping("/{id}")
    public Book getById(@PathVariable Integer id) {
        return bookService.getById(id);
    }
    @GetMapping
    public List<Book> getAll() {
        return bookService.getAll();
    }
}

1.3 接口测试

service 接口测试（JUnit）

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfig.class)
public class BookServiceTest {
    @Autowired
    private BookService bookService;
    @Test
    public void testDeleteById(){
        System.out.println(bookService.delete(2));
    }
    @Test
    public void testGetById(){
        System.out.println(bookService.getById(1));
    }
    @Test
    public void testGetAll(){
        System.out.println(bookService.getAll());
    }
}

controller 接口测试（PostMan）

post: http://localhost:80/books
{"type": "def", "name": "123", "description": "abc"}

put: http://localhost:80/books
{"id": "1", "type": "def", "name": "123", "description": "abc"}

delete: http://localhost:80/books/2

get: http://localhost:80/books/3

get: http://localhost:80/books

2 统一结果封装

前端数据传输格式协议

表现层与协议实现

@Data
public class Result { // 结果模型类
    private Integer code;
    private Object data;
    private String msg;
}

public class Code {       // 状态码类
    public static final Integer SAVE_OK = 20011;
    public static final Integer DELETE_OK = 20021;
    public static final Integer UPDATE_OK = 20031;
    public static final Integer GET_OK = 20041;

    public static final Integer SAVE_ERR = 20010;
    public static final Integer DELETE_ERR = 20020;
    public static final Integer UPDATE_ERR = 20030;
    public static final Integer GET_ERR = 20040;
}

@RestController
@RequestMapping("/books")
public class BookController {
    @Autowired
    private BookService bookService;

    @PostMapping
    public Result save(@RequestBody Book book) {
        boolean flag = bookService.save(book);
        return new Result(flag ? Code.SAVE_OK:Code.SAVE_ERR, flag);
    }
    
  ...
        
    @GetMapping
    public Result getAll() {
        List<Book> bookList = bookService.getAll();
        Integer code = bookList != null ? Code.GET_OK : Code.GET_ERR;
        String msg = bookList != null ? "" : "数据查询失败，请重试！";
        return new Result(code, bookList, msg);
    }
}

3 统一异常处理

3.1 异常处理器

出现异常现象的常见位置与常见诱因如下
- 框架内部地出的异常：因使用不合规导致
- 数据层抛出的异常：因外部服务器故障导致（例如：服务器访问超时）
- 业务层抛出的异常：因业务逻辑书写错误导致（例如：遍历业务书写操作，导致索引异常等
- 表现层抛出的异常：因数据收集、校验等规则导致（例如：不匹配的数据类型间导致异常）
- 工具类抛出的异常：因工具类书写不严谨不够健壮导致（例如：必要释放的连接长期未释放等）

异常处理器：集中的、统一的处理项目中出现的异常

package com.itheima.controller;

@RestControllerAdvice
public class ProjectExceptionAdvice {
    @ExceptionHandler(Exception.class)
    public Result doException(Exception ex){
        return new Result(666, null, "嘿嘿,异常你哪里跑！");
    }
}

3.2 项目异常处理

业务异常（BusinessException）：规范 or 不规范的用户行为产生的异常
- 发送对应消息传递给用户，提醒规范操作
系统异常（SystemException）：项目运行过程中可预计且无法避免的异常
- 发送固定消息传递给用户，安抚用户
- 发送特定消息给运维人员，提醒维护
- 记录日志
其他异常（Exception）：编程人员未预期到的异常
- 发送固定消息传递给用户，安抚用户
- 发送特定消息给运维人员，提醒维护
- 记录日志

自定义异常编码

public class Code {
    public static final Integer SYSTEM_ERR = 50001;
    public static final Integer SYSTEM_TIMEOUT_ERR = 50002;
    public static final Integer SYSTEM_UNKNOW_ERR = 59999;
    public static final Integer BUSINESS_ERR = 60002;
}

拦截并处理异常

package com.itheima.controller;

@RestControllerAdvice
public class ProjectExceptionAdvice {
    @ExceptionHandler(SystemException.class)
    public Result doSystemException(SystemException ex){
        return new Result(ex.getCode(), null, ex.getMessage());
    }
    @ExceptionHandler(BusinessException.class)
    public Result doBusinessException(BusinessException ex){
        return new Result(ex.getCode(), null, ex.getMessage());
    }
    @ExceptionHandler(Exception.class)
    public Result doOtherException(Exception ex){
        return new Result(Code.SYSTEM_UNKNOW_ERR, null, "系统繁忙，请稍后再试！");
    }
}

4 前后台协议联调

4.1 环境准备

将静态资源拷贝到 webapp 下，book.html 中的核心代码如下：

<body>
    <el-button @click="getAll()" class="dalfBut">查询</el-button>

    <el-button type="primary" class="butT" @click="handleCreate()">新建</el-button>
    <el-button @click="dialogFormVisible = false">取消</el-button>
    <el-button type="primary" @click="handleAdd()">确定</el-button>

    <el-button type="primary" size="mini" @click="handleUpdate(scope.row)">编辑</el-button>
    <el-button @click="dialogFormVisible4Edit = false">取消</el-button>
    <el-button type="primary" @click="handleEdit()">确定</el-button>

    <el-button type="danger" size="mini" @click="handleDelete(scope.row)">删除</el-button>
</body>

<script>
    var vue = new Vue({
        methods: {
            getAll() {},         // 1. 列表展示
            resetForm() {},          // 重置表单
            handleAdd () {},     // 2. 添加功能
            handleCreate() {},       // 添加窗口
            handleEdit() {},     // 3. 修改功能
            handleUpdate(row) {},    // 编辑窗口
            handleDelete(row) {} // 4. 删除功能
        }
    })
</script>

因为 SpringMVC 会拦截，所以需要在 SpringConfig 的配置类中将其放行

@Configuration       
public class SpringMvcSupport extends WebMvcConfigurationSupport {
    @Override
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");
        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
        registry.addResourceHandler("/js/**").addResourceLocations("/js/");
        registry.addResourceHandler("/plugins/**").addResourceLocations("/plugins/");
    }
}

@Configuration   
@ComponentScan({"com.itheima.controller","com.itheima.config"})
@EnableWebMvc
public class SpringMvcConfig {
}

4.2 列表展示

页面的钩子函数 created() 调用了 this.getAll() 方法，使用 axios 发送异步请求从后台获取数据
```
getAll() {
    axios.get("/books").then((res)=>{
        this.dataList = res.data.data;
    });
}
```
访问 http://localhost/pages/books.html 进行测试

4.3 添加功能

页面的新建按钮绑定了 @click="handleCreate()" 方法，在方法中打开新增面板

handleCreate() {
    this.dialogFormVisible = true;
    this.resetForm();
},
    
resetForm(){
    this.formData = {};
}

确定按钮绑定了 @click="handleAdd()" 方法，在方法中发送请求和数据，响应成功后将新增面板关闭并重新查询数据

handleAdd () {
    axios.post("/books",this.formData).then((res)=>{
        if(res.data.code == 20011){          // 如果操作成功，关闭弹层，显示数据
            this.dialogFormVisible = false;
            this.$message.success("添加成功");
        }else if(res.data.code == 20010){    // 如果操作失败，提示错误信息
            this.$message.error("添加失败");
        }else{
            this.$message.error(res.data.msg);
        }
    }).finally(()=>{
        this.getAll();
    });
}

后台返回操作结果，将 Dao 层的增删改方法返回值从 void 改成 int

@Insert("insert into tbl_book (type,name,description) values(#{type},#{name},#{description})")
public int save(Book book);

@Update("update tbl_book set type=#{type}, name=#{name}, description=#{description} where id=#{id}")
public int update(Book book);

@Delete("delete from tbl_book where id = #{id}")
public int delete(Integer id);

在 BookServiceImpl 中，增删改方法根据 Dao 的返回值来决定返回 true/false

public boolean save(Book book) {
    return bookDao.save(book) > 0;
}
public boolean update(Book book) {
    return bookDao.update(book) > 0;
}
public boolean delete(Integer id) {
    return bookDao.delete(id) > 0;
}

4.4 编辑功能

页面中的编辑按钮绑定了 @click="handleUpdate(scope.row)"，在方法中根据 ID 查询图书信息

handleUpdate(row) {
    axios.get("/books/"+row.id).then((res)=>{
        if(res.data.code == 20041){          // 如果查询成功, 打开修改面板回显数据
            this.formData = res.data.data;
            this.dialogFormVisible4Edit = true;
        }else{                               // 如果查询失败, 提示错误信息
            this.$message.error(res.data.msg);
        }
    });
}

在 handleEdit 方法中发送异步请求提交修改数据

handleEdit() {
    axios.put("/books",this.formData).then((res)=>{
        if(res.data.code == 20031){          // 如果操作成功，关闭弹层，显示数据
            this.dialogFormVisible4Edit = false;
            this.$message.success("修改成功");
        }else if(res.data.code == 20030){    // 如果操作失败，提示错误信息
            this.$message.error("修改失败");
        }else{
            this.$message.error(res.data.msg);
        }
    }).finally(()=>{
        this.getAll();
    });
}

4.5 删除功能

handleDelete(row) {
    this.$confirm("此操作永久删除当前数据，是否继续？","提示",{
        type:'info'
    }).then(()=>{           // 用户点击确定，发送异步请求, 并携带需要删除数据的主键ID
        axios.delete("/books/"+row.id).then((res)=>{
            if(res.data.code == 20021){     
                this.$message.success("删除成功");
            }else{                          
                this.$message.error("删除失败");
            }
        }).finally(()=>{
            this.getAll();
        });
    }).catch(()=>{          // 用户点击取消,提示操作已经被取消
        this.$message.info("取消删除操作");
    });
}

5 基于 SpringBoot 整合

需求：根据之前的 Spring 案例，实现基于 SpringBoot 的 SSM 整合

config 类：全部删除
dao 类：设置 @Mapper
test 类：设置 @SpringBootTest

pom.xml：配置必要的资源坐标

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.16</version>
</dependency>

application.yml：配置数据源、端口等

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ssm_db
    username: root
    password: 123456

static：静态资源，index.html 设置主页

<script>
    document.location.href="pages/books.html”;
</script>

案例源码：https://wwb.lanzouo.com/ic4f42166e7c