04 SpringMVC - HelloWorld开发者社区

SpringMVC入门案例

创建Web工程，导入依赖

<dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.16</version>
    </dependency>
</dependencies>

定义处理请求功能的类（UserController）

//定义表现层控制器bean
@Controller
public class UserController {
    //设置映射路径为/save，即外部访问路径
    @RequestMapping("/save")
    //设置当前操作返回结果为指定json数据（本质上是一个字符串信息）
    @ResponseBody
    public String save(){
        System.out.println("user save ...");
        return "{'info':'springmvc'}";
    }
}

编写SpringMVC配置类，加载处理请求的Bean

//springmvc配置类，本质上还是一个spring配置类
@Configuration
@ComponentScan("cn.lixuan.controller")
public class SpringMvcConfig {
}

加载SpringMVC配置，并设置SpringMVC请求拦截的路径

//web容器配置类
public class ServletContainersInitConfig extends AbstractDispatcherServletInitializer {
    //加载springmvc配置类，产生springmvc容器（本质还是spring容器）
    protected WebApplicationContext createServletApplicationContext() {
        //初始化WebApplicationContext对象
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        //加载指定配置类
        ctx.register(SpringMvcConfig.class);
        return ctx;
    }

    //设置由springmvc控制器处理的请求映射路径
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    //加载非SpringMVC对应的bean
    protected WebApplicationContext createRootApplicationContext() {
        return null;
    }
}

// 简化格式

public class ServletContainersInitConfig extends AbstractAnnotationConfigDispatcherServletInitializer{
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{SpringMvcConfig.class}
    };
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{SpringConfig.class};
    }
}

Controller加载控制

@Configuration
@ComponentScan(value = "cn.lixuan",
               excludeFilters = @ComponentScan.Filter(
                   type = FilterType.ANNOTATION,
                   classes = Controller.class
               )
              )
public class SpringConfig {
}

请求与响应

@RequestMapping

@Controller
//类上方配置的请求映射与方法上面配置的请求映射连接在一起，形成完整的请求映射路径
@RequestMapping("/user")
public class UserController {
    //请求路径映射
    @RequestMapping("/save") //此时save方法的访问路径是：/user/save
    @ResponseBody
    public String save(){
        System.out.println("user save ...");
        return "{'module':'user save'}";
    }
}

GET请求传递普通参数

//普通参数：请求参数与形参名称对应即可完成参数传递
//http://localhost:8080/commonParam?name=lixuan&age=18
@RequestMapping("/commonParam")
@ResponseBody
public String commonParam(String name ,int age){
    System.out.println("普通参数传递 name ==> "+name);
    System.out.println("普通参数传递 age ==> "+age);
    return "{'module':'common param'}";
}

解决GET请求中文乱码问题

<build>
    <plugins>
      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.1</version>
        <configuration>
          <port>80</port><!--tomcat端口号-->
          <path>/</path> <!--虚拟目录-->
          <uriEncoding>UTF-8</uriEncoding><!--访问路径编解码字符集-->
        </configuration>
      </plugin>
    </plugins>
  </build>

POST请求传递普通参数（同Get）

POST请求中文乱码处理

// 在加载SpringMVC配置的配置类中指定字符过滤器。
public class ServletContainersInitConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

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

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

    //乱码处理
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        filter.setEncoding("UTF-8");
        return new Filter[]{filter};
    }
}

五种类型参数传递

普通参数

//普通参数：请求参数名与形参名不同时，使用@RequestParam注解关联请求参数名称与形参名称之间的关系
@RequestMapping("/commonParamDifferentName")
@ResponseBody
public String commonParamDifferentName(@RequestParam("name") String userName , int age){
    System.out.println("普通参数传递 userName ==> "+userName);
    System.out.println("普通参数传递 age ==> "+age);
    return "{'module':'common param different name'}";
}

POJO类型参数

@Data
public class User {
    private String name;
    private int age;
}

// 请求参数key的名称要和POJO中属性的名称一致，否则无法封装

@RequestMapping("/pojoParam")
@ResponseBody
public String pojoParam(User user){
    System.out.println("pojo参数传递 user ==> "+user);
    return "{'module':'pojo param'}";
}

嵌套POJO类型参数

@Data
public class User {
    private String name;
    private int age;
    private Address address;
}

@Data
public class Address {
    private String province;
    private String city;
}

  //嵌套POJO参数：嵌套属性按照层次结构设定名称即可完成参数传递
  //http://localhost:8080/pojoContainPojoParam?name=lixuan&age=18&address.province=hubei&address.city=wuhan
  @RequestMapping("/pojoContainPojoParam")
  @ResponseBody
  public String pojoContainPojoParam(User user){
      System.out.println("pojo嵌套pojo参数传递 user ==> "+user);
      return "{'module':'pojo contain pojo param'}";
  }

数组类型参数

//数组参数：同名请求参数可以直接映射到对应名称的形参数组对象中
@RequestMapping("/arrayParam")
@ResponseBody
public String arrayParam(String[] likes){
    System.out.println("数组参数传递 likes ==> "+ Arrays.toString(likes));
    return "{'module':'array param'}";
}

集合类型参数

//集合参数：同名请求参数可以使用@RequestParam注解映射到对应名称的集合对象中作为数据
@RequestMapping("/listParam")
@ResponseBody
public String listParam(@RequestParam List<String> likes){
    System.out.println("集合参数传递 likes ==> "+ likes);
    return "{'module':'list param'}";
}

json数据参数传递

json数据参数介绍
- json普通数组（["","","",...]）
- json对象（{key:value,key:value,...}）
- json对象数组（[{key:value,...},{key:value,...}]）

传递json普通数组

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.0</version>
</dependency>

@Configuration
@ComponentScan("cn.lixuan.controller")
//开启json数据类型自动转换
@EnableWebMvc
public class SpringMvcConfig {
}

//集合参数：json格式
//1.开启json数据格式的自动转换，在配置类中开启@EnableWebMvc
//2.使用@RequestBody注解将外部传递的json数组数据映射到形参的集合对象中作为数据
@RequestMapping("/listParamForJson")
@ResponseBody
public String listParamForJson(@RequestBody List<String> likes){
    System.out.println("list common(json)参数传递 list ==> "+likes);
    return "{'module':'list common for json param'}";
}

传递json对象

//POJO参数：json格式
//1.开启json数据格式的自动转换，在配置类中开启@EnableWebMvc
//2.使用@RequestBody注解将外部传递的json数据映射到形参的实体类对象中，要求属性名称一一对应
@RequestMapping("/pojoParamForJson")
@ResponseBody
public String pojoParamForJson(@RequestBody User user){
    System.out.println("pojo(json)参数传递 user ==> "+user);
    return "{'module':'pojo for json param'}";
}

传递json对象数组

//集合参数：json格式
//1.开启json数据格式的自动转换，在配置类中开启@EnableWebMvc
//2.使用@RequestBody注解将外部传递的json数组数据映射到形参的保存实体类对象的集合对象中，要求属性名称一一对应
@RequestMapping("/listPojoParamForJson")
@ResponseBody
public String listPojoParamForJson(@RequestBody List<User> list){
    System.out.println("list pojo(json)参数传递 list ==> "+list);
    return "{'module':'list pojo for json param'}";
}

日期类型参数传递

//日期参数 http://localhost:80/dataParam?date=2088/08/08&date1=2088-08-18&date2=2088/08/28 8:08:08
//使用@DateTimeFormat注解设置日期类型数据格式，默认格式yyyy/MM/dd
@RequestMapping("/dataParam")
@ResponseBody
public String dataParam(Date date,
                  @DateTimeFormat(pattern="yyyy-MM-dd") Date date1,
                  @DateTimeFormat(pattern="yyyy/MM/dd HH:mm:ss") Date date2){
    System.out.println("参数传递 date ==> "+date);
    System.out.println("参数传递 date1(yyyy-MM-dd) ==> "+date1);
    System.out.println("参数传递 date2(yyyy/MM/dd HH:mm:ss) ==> "+date2);
    return "{'module':'data param'}";
}

响应json数据

//响应POJO对象
//返回值为实体类对象，设置返回值为实体类类型，即可实现返回对应对象的json数据，需要依赖@ResponseBody注解和@EnableWebMvc注解
@RequestMapping("/toJsonPOJO")
@ResponseBody
public User toJsonPOJO(){
    System.out.println("返回json对象数据");
    User user = new User();
    user.setName("xuan");
    user.setAge(15);
    return user;
}

//响应POJO集合对象
//返回值为集合对象，设置返回值为集合类型，即可实现返回对应集合的json数组数据，需要依赖@ResponseBody注解和@EnableWebMvc注解
@RequestMapping("/toJsonList")
@ResponseBody
public List<User> toJsonList(){
    System.out.println("返回json集合数据");
    User user1 = new User();
    user1.setName("数据科学");
    user1.setAge(15);

    User user2 = new User();
    user2.setName("大数据技术");
    user2.setAge(12);

    List<User> userList = new ArrayList<User>();
    userList.add(user1);
    userList.add(user2);

    return userList;
}

REST风格

RESTful介绍
- http://localhost/users 查询全部用户信息GET （查询） http://localhost/users/1 查询指定用户信息GET（查询） http://localhost/users 添加用户信息POST（新增/保存） http://localhost/users 修改用户信息PUT（修改/更新） http://localhost/users/1 删除用户信息DELETE（删除）

RESTful入门案例

@RestController   
@RequestMapping("/books")
@CrossOrigin(origins = "*",maxAge = 3600)
public class BookController {

    @PostMapping//使用@PostMapping简化Post请求方法对应的映射配置
    public String save(@RequestBody Book book){
        System.out.println("book save..." + book);
        return "{'module':'book save'}";
    }

    @DeleteMapping("/{id}")  //使用@DeleteMapping简化DELETE请求方法对应的映射配置
    public String delete(@PathVariable Integer id){
        System.out.println("book delete..." + id);
        return "{'module':'book delete'}";
    }

    @PutMapping   //使用@PutMapping简化Put请求方法对应的映射配置
    public String update(@RequestBody Book book){
        System.out.println("book update..."+book);
        return "{'module':'book update'}";
    }

    @GetMapping("/{id}")    //使用@GetMapping简化GET请求方法对应的映射配置
    public String getById(@PathVariable Integer id){
        System.out.println("book getById..."+id);
        return "{'module':'book getById'}";
    }

    @GetMapping      //使用@GetMapping简化GET请求方法对应的映射配置
    public String getAll(){
        System.out.println("book getAll...");
        return "{'module':'book getAll'}";
    }
}

案例：基于RESTful页面数据交互

POJO实体类

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

SpringMVC容器初始化类

public class ServletContainersInitConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

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

    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
    //乱码处理
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        filter.setEncoding("UTF-8");
        return new Filter[]{filter};
    }
}

SpringMVC配置类

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

制作SpringMVC控制器，并通过PostMan测试接口功能

@RestController
@RequestMapping("/books")
@CrossOrigin(origins = "*",maxAge = 3600)
public class BookController {

    @PostMapping
    public String save(@RequestBody Book book){
        System.out.println("book save ==> "+ book);
        return "{'module':'book save success'}";
    }

    @GetMapping
    public List<Book> getAll(){
        System.out.println("book getAll is running ...");
        List<Book> bookList = new ArrayList<Book>();

        Book book1 = new Book();
        book1.setType("计算机");
        book1.setName("SpringMVC入门教程");
        book1.setDescription("小试牛刀");
        bookList.add(book1);

        Book book2 = new Book();
        book2.setType("计算机");
        book2.setName("SpringMVC实战教程");
        book2.setDescription("一代宗师");
        bookList.add(book2);

        Book book3 = new Book();
        book3.setType("计算机丛书");
        book3.setName("SpringMVC实战教程进阶");
        book3.setDescription("一代宗师呕心创作");
        bookList.add(book3);

        return bookList;
    }
}

设置对静态资源的访问放行

@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {
    //设置静态资源访问过滤，当前类需要设置为配置类，并被扫描加载
    @Override
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        //当访问/pages/????时候，从/pages目录下查找内容
        registry.addResourceHandler("/pages/**")
            .addResourceLocations("/pages/");
        registry.addResourceHandler("/js/**")
            .addResourceLocations("/js/");                
        registry.addResourceHandler("/css/**")
            .addResourceLocations("/css/");       
        registry.addResourceHandler("/plugins/**")
            .addResourceLocations("/plugins/");
    }
}

前端页面通过异步提交访问后台控制器

//添加
saveBook () {
    axios.post("/books",this.formData)
},
//主页列表查询
getAll() {
    axios.get("/books").then((res)=>{
        this.dataList = res.data;
    });
},

SSM整合

添加依赖

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.6</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.0</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>

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

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

    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.0</version>
    </dependency>
</dependencies>

Spring整合MyBatis

创建数据库和表

-- 创建ssm_db数据库
CREATE DATABASE IF NOT EXISTS ssm_db CHARACTER SET utf8;

-- 使用ssm_db数据库
USE ssm_db;

-- 创建tbl_book表
CREATE TABLE tbl_book(
    id INT PRIMARY KEY AUTO_INCREMENT, -- 图书编号
    TYPE VARCHAR(100), -- 图书类型
    NAME VARCHAR(100), -- 图书名称
    description VARCHAR(100) -- 图书描述
);
-- 添加初始化数据
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring实战 第5版','Spring入门经典教材，深入理解Spring原理技术内幕');
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring 5核心原理与30个类手写实战','十年沉淀之作,手写Spring精华思想');
INSERT INTO tbl_book VALUES(NULL,'计算机理论','Spring 5设计模式','深入Spring源码剖析,Spring源码蕴含的10大设计模式');
INSERT INTO tbl_book VALUES(NULL,'市场营销','直播就该这么做:主播高效沟通实战指南','李子柒、李佳琦、薇娅成长为网红的秘密都在书中');
INSERT INTO tbl_book VALUES(NULL,'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');
INSERT INTO tbl_book VALUES(NULL,'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+');

jdbc.properties属性文件

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

JdbcConfig配置类

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;
    //配置连接池
    @Bean
    public DataSource dataSource(){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }
    //Spring事务管理需要的平台事务管理器对象
    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource){
        DataSourceTransactionManager ds = new DataSourceTransactionManager();
        ds.setDataSource(dataSource);
        return ds;
    }
}

MybatisConfig配置类

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

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

SpringConfig配置类

@Configuration
@ComponentScan({"cn.lixuan.service"})
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class,MyBatisConfig.class})
@EnableTransactionManagement //开启Spring事务管理
public class SpringConfig {
}

Spring整合SpringMVC

SpringMvcConfig配置类

@Configuration
@ComponentScan("cn.lixuan.controller")
@EnableWebMvc
public class SpringMvcConfig {
}

ServletConfig配置类，加载SpringMvcConfig和SpringConfig配置类

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[]{"/"};
    }
}

功能模块开发

数据层开发(BookDao)

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

@Mapper
public interface BookDao {

    //@Insert("insert into tbl_book values(null,#{type},#{name},#{description})")
    @Insert("insert into tbl_book (type,name,description) values(#{type},#{name},#{description})")
    public int save(Book book);  //返回值表示影响的行数

    @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);

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

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

业务层开发

@Transactional //表示所有方法进行事务管理
public interface BookService {

    /**
     * 保存
     * @param book
     * @return
     */
    public boolean save(Book book);

    /**
     * 修改
     * @param book
     * @return
     */
    public boolean update(Book book);

    /**
     * 按id删除
     * @param id
     * @return
     */
    public boolean delete(Integer id);

    /**
     * 按id查询
     * @param id
     * @return
     */
    public Book getById(Integer id);

    /**
     * 查询全部
     * @return
     */
    public List<Book> getAll();
}

@Service
public class BookServiceImpl implements BookService {
    @Autowired
    private BookDao bookDao;
    //增删改的方法判断了影响的行数是否大于0，而不是固定返回true
    public boolean save(Book book) {
        return bookDao.save(book) > 0;
    }
    //增删改的方法判断了影响的行数是否大于0，而不是固定返回true
    public boolean update(Book book) {
        return bookDao.update(book) > 0;
    }
    //增删改的方法判断了影响的行数是否大于0，而不是固定返回true
    public boolean delete(Integer id) {
        return bookDao.delete(id) > 0;
    }

    public Book getById(Integer id) {
        if(id < 0){
            throw new BusinessException(Code.BUSINESS_ERR,"请不要使用你的技术挑战我的耐性!");
        }
        return bookDao.getById(id);
    }
    public List<Book> getAll() {
        return bookDao.getAll();
    }
}

表现层开发(BookController)

@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();
    }
}

接口测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfig.class)
public class BookServiceTest {

    @Autowired
    private BookService bookService;

    @Test
    public void testGetById(){
        Book book = bookService.getById(1);
        System.out.println(book);
    }

    @Test
    public void testGetAll(){
        List<Book> all = bookService.getAll();
        System.out.println(all);
    }
}

表现层数据封装

Result类封装响应结果

@Data
public class Result {
    //描述统一格式中的编码，用于区分操作，可以简化配置0或1表示成功失败
    private Integer code;
    //描述统一格式中的数据
    private Object data;
    //描述统一格式中的消息，可选属性
    private String msg;
}

Code类封装响应码

//状态码
public class Code {
    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;
}

表现层数据封装返回Result对象

@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);
    }

    @PutMapping
    public Result update(@RequestBody Book book) {
        boolean flag = bookService.update(book);
        return new Result(flag ? Code.UPDATE_OK:Code.UPDATE_ERR,flag);
    }

    @DeleteMapping("/{id}")
    public Result delete(@PathVariable Integer id) {
        boolean flag = bookService.delete(id);
        return new Result(flag ? Code.DELETE_OK:Code.DELETE_ERR,flag);
    }

    @GetMapping("/{id}")
    public Result getById(@PathVariable Integer id) {
        Book book = bookService.getById(id);
        Integer code = book != null ? Code.GET_OK : Code.GET_ERR;
        String msg = book != null ? "" : "数据查询失败，请重试！";
        return new Result(code,book,msg);
    }

    @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);
    }
}

异常处理器

编写异常处理器

@RestControllerAdvice  //用于标识当前类为REST风格对应的异常处理器
public class ProjectExceptionAdvice {

    //统一处理所有的Exception异常
    @ExceptionHandler(Exception.class)
    public Result doOtherException(Exception ex){
        return new Result(666,null);
    }
}

项目异常处理方案

业务异常：发送对应消息传递给用户
系统异常，其他异常：
- 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

自定义项目系统级异常

//自定义异常处理器，用于封装异常信息，对异常进行分类
public class SystemException extends RuntimeException{
    private Integer code;

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public SystemException(Integer code, String message) {
        super(message);
        this.code = code;
    }

    public SystemException(Integer code, String message, Throwable cause) {
        super(message, cause);
        this.code = code;
    }
}

自定义项目业务级异常

//自定义异常处理器，用于封装异常信息，对异常进行分类
public class BusinessException extends RuntimeException{
    private Integer code;

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public BusinessException(Integer code, String message) {
        super(message);
        this.code = code;
    }

    public BusinessException(Integer code,String message,Throwable cause) {
        super(message, cause);
        this.code = code;
    }
}

自定义异常编码

public class Code {

    //之前其他状态码省略没写，以下是新补充的状态码，可以根据需要自己补充

    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;

}

触发自定义异常

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

    //在getById演示触发异常，其他方法省略没有写进来
    public Book getById(Integer id) {
        //模拟业务异常，包装成自定义异常
        if(id <0){
            throw new BusinessException(Code.BUSINESS_ERR,"请不要使用你的技术挑战我的耐性!");
        }
    }
}

在异常通知类中拦截并处理异常

@RestControllerAdvice //用于标识当前类为REST风格对应的异常处理器
public class ProjectExceptionAdvice {
    //@ExceptionHandler用于设置当前处理器类对应的异常类型
    @ExceptionHandler(SystemException.class)
    public Result doSystemException(SystemException ex){
        //记录日志
        //发送消息给运维
        //发送邮件给开发人员,ex对象发送给开发人员
        return new Result(ex.getCode(),null,ex.getMessage());
    }

    @ExceptionHandler(BusinessException.class)
    public Result doBusinessException(BusinessException ex){
        return new Result(ex.getCode(),null,ex.getMessage());
    }

    //除了自定义的异常处理器，保留对Exception类型的异常处理，用于处理非预期的异常
    @ExceptionHandler(Exception.class)
    public Result doOtherException(Exception ex){
        //记录日志
        //发送消息给运维
        //发送邮件给开发人员,ex对象发送给开发人员
        return new Result(Code.SYSTEM_UNKNOW_ERR,null,"系统繁忙，请稍后再试！");
    }
}

SSM整合页面开发

列表查询功能

//列表
getAll() {
    //发送ajax请求
    axios.get("/books").then((res)=>{
        this.dataList = res.data.data;
    });
}

添加功能

//弹出添加窗口
handleCreate() {
    this.dialogFormVisible = true;
    this.resetForm();
},
//重置表单
resetForm() {
    this.formData = {};
},
//添加
handleAdd () {
    //发送ajax请求
    axios.post("/books",this.formData).then((res)=>{
        console.log(res.data);
        //如果操作成功，关闭弹层，显示数据
        if(res.data.code == 20011){
            this.dialogFormVisible = false;
            this.$message.success("添加成功");
        }else if(res.data.code == 20010){
            this.$message.error("添加失败");
        }else{
            this.$message.error(res.data.msg);
        }
    }).finally(()=>{
        this.getAll();
    });
},

修改功能

//弹出编辑窗口
handleUpdate(row) {
    // console.log(row);   //row.id 查询条件
    //查询数据，根据id查询
    axios.get("/books/"+row.id).then((res)=>{
        // console.log(res.data.data);
        if(res.data.code == 20041){
            //展示弹层，加载数据
            this.formData = res.data.data;
            this.dialogFormVisible4Edit = true;
        }else{
            this.$message.error(res.data.msg);
        }
    });
}

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

删除功能

// 删除
handleDelete(row) {
    //1.弹出提示框
    this.$confirm("此操作永久删除当前数据，是否继续？","提示",{
        type:'info'
    }).then(()=>{
        //2.做删除业务
        axios.delete("/books/"+row.id).then((res)=>{
            if(res.data.code == 20021){
                this.$message.success("删除成功");
            }else{
                this.$message.error("删除失败");
            }
        }).finally(()=>{
            this.getAll();
        });
    }).catch(()=>{
        //3.取消删除
        this.$message.info("取消删除操作");
    });
}

拦截器

定义拦截器

@Component //注意当前类必须受Spring容器控制
//定义拦截器类，实现HandlerInterceptor接口
public class ProjectInterceptor implements HandlerInterceptor {
    @Override
    //原始方法调用前执行的内容
    //返回值类型可以拦截控制的执行，true放行，false终止
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...");
        return true;
    }

    @Override
    //原始方法调用后执行的内容
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle...");
    }

    @Override
    //原始方法调用完成后执行的内容
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion...");
    }
}

配置加载拦截器

@Configuration
@ComponentScan({"cn.lixuan.controller"})
@EnableWebMvc
//实现WebMvcConfigurer接口可以简化开发，但具有一定的侵入性
public class SpringMvcConfig implements WebMvcConfigurer {
    @Autowired
    private ProjectInterceptor projectInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //配置多拦截器
        //访问/books或者/books/1...都拦截
        registry.addInterceptor(projectInterceptor)
            .addPathPatterns("/books","/books/*");
    }
}

拦截器链配置

定义第二个拦截器

@Component
public class ProjectInterceptor2 implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...222");
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle...222");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion...222");
    }
}

配置第二个拦截器

@Configuration
@ComponentScan({"com.itheima.controller"})
@EnableWebMvc
//实现WebMvcConfigurer接口可以简化开发，但具有一定的侵入性
public class SpringMvcConfig implements WebMvcConfigurer {
    @Autowired
    private ProjectInterceptor projectInterceptor;
    @Autowired
    private ProjectInterceptor2 projectInterceptor2;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //配置多拦截器
        registry.addInterceptor(projectInterceptor)
            .addPathPatterns("/books","/books/*");
        registry.addInterceptor(projectInterceptor2)
            .addPathPatterns("/books","/books/*");
    }
}