SSM基础整合

SSM基础整合

SSM基础整合

SSM整合流程

1. 创建工程

2. SSM整合

   • Spring

     • SpringConfig

     • @Configuration
       @ComponentScan({"com.ityc.service"})
       @PropertySource("classpath:jdbc.properties")
       @Import({JdbcConfig.class,MybatisConfig.class})
       //事物
       @EnableTransactionManagement
       public class SpringConfig {
       }
       
       

   • MyBatis

     • MyBatisConfig

       public class MybatisConfig {
           @Bean
           public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
               SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
               factoryBean.setDataSource(dataSource);
               factoryBean.setTypeAliasesPackage("com.ityc.domain");
       
               return factoryBean;
           }
       
           @Bean
           public MapperScannerConfigurer mapperScannerConfigurer(){
               MapperScannerConfigurer msc= new MapperScannerConfigurer();
               msc.setBasePackage("com.ityc.dao");
               return msc;
           }
       }
       
       

     • JdbcConfig

       public class JdbcConfig {
           @Value("${jdbc.driver}")
           private String driver;
           @Value("${jdbc.url}")
           private String url;
           @Value("${jdbc.username}")
           private String username;
           @Value("${jdbc.passworld}")
           private String passworld;
       
       
           //导入MySQL
           @Bean
           public DataSource DataSource(){
               DruidDataSource dataSource = new DruidDataSource();
               dataSource.setDriverClassName(driver);
               dataSource.setUrl(url);
               dataSource.setUsername(username);
               dataSource.setPassword(passworld);
               return dataSource;
           }
       
           //事物
           @Bean
           public PlatformTransactionManager transactionManager(DataSource dataSource){
               DataSourceTransactionManager ds = new DataSourceTransactionManager();
               ds.setDataSource(dataSource);
               return ds;
       
           }
       }
       
       

     • jdbc.properties

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

   • SpringMVC

     • SpringMvcConfig

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

3. 功能模块

   • 表与实体类

     package com.ityc.domain;
     
     public class Book {
         private Integer id;
         private String type;
         private String name;
         private String description;
     
     
     
         public Integer getId() {
             return id;
         }
     
         public void setId(Integer id) {
             this.id = id;
         }
     
         public String getType() {
             return type;
         }
     
         public void setType(String type) {
             this.type = type;
         }
     
         public String getName() {
             return name;
         }
     
         public void setName(String name) {
             this.name = name;
         }
     
         public String getDescription() {
             return description;
         }
     
         public void setDescription(String description) {
             this.description = description;
         }
     
         @Override
         public String toString() {
             return "Book{" +
                     "id=" + id +
                     ", type='" + type + '\'' +
                     ", name='" + name + '\'' +
                     ", description='" + description + '\'' +
                     '}';
         }
     }
     
     

     DROP TABLE IF EXISTS `tbl_book`;
     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` VALUES (1, '计算机理论', 'Spring实战 第5版', 'Spring入门经典教程，深入理解Spring原理技术内幕');
     INSERT INTO `tbl_book` VALUES (2, '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 (3, '计算机理论', 'Spring 5 设计模式', '深入Spring源码剖析Spring源码中蕴含的10大设计模式');
     INSERT INTO `tbl_book` VALUES (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，带你成为Spring MVC开发高手');
     INSERT INTO `tbl_book` VALUES (5, '计算机理论', '轻量级Java Web企业应用实战', '源码级剖析Spring框架，适合已掌握Java基础的读者');
     INSERT INTO `tbl_book` VALUES (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，针对Java SE9、10、11全面更新');
     INSERT INTO `tbl_book` VALUES (7, '计算机理论', '深入理解Java虚拟机', '5个维度全面剖析JVM，大厂面试知识点全覆盖');
     INSERT INTO `tbl_book` VALUES (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');
     INSERT INTO `tbl_book` VALUES (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语言的编程思想和核心技术');
     INSERT INTO `tbl_book` VALUES (10, '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 (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');
     INSERT INTO `tbl_book` VALUES (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+');
     
     

   • dao（接口+自动代理）

     package com.ityc.dao;
     
     import com.ityc.domain.Book;
     import org.apache.ibatis.annotations.Delete;
     import org.apache.ibatis.annotations.Insert;
     import org.apache.ibatis.annotations.Select;
     import org.apache.ibatis.annotations.Update;
     import org.springframework.web.servlet.config.annotation.EnableWebMvc;
     
     import java.util.List;
     
     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 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（接口+实体类）

     • 业务层接口测试（整合JUnit）

     //接口
     package com.ityc.service;
     
     import com.ityc.domain.Book;
     import org.apache.ibatis.annotations.Delete;
     import org.apache.ibatis.annotations.Insert;
     import org.apache.ibatis.annotations.Select;
     import org.apache.ibatis.annotations.Update;
     import org.springframework.transaction.annotation.Transactional;
     
     import java.util.List;
     
     //开启事物
     @Transactional
     public interface BookService {
     
         /**
          * 保存
          * @param book
          * @return
          */
     
         public boolean save(Book book);
     
         /**
          * 修改
          * @param book
          * @return
          */
         public boolean update(Book book);
     
         /**
          * 删除 根据id
          * @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();
     }
     
     

     //实现类
     package com.ityc.service.impl;
     
     import com.ityc.dao.BookDao;
     import com.ityc.domain.Book;
     import com.ityc.service.BookService;
     import org.springframework.beans.factory.annotation.Autowired;
     import org.springframework.stereotype.Service;
     
     import java.util.List;
     @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);
             
             if(bookDao.getById(id)!=null){
                 bookDao.delete(id);
                 return true;
             }else{
                  return false;
             }
         }
     
         public Book getById(Integer id) {
             return bookDao.getById(id);
         }
     
         public List<Book> getALL() {
             return bookDao.getALL();
         }
     }
     
     

     //测试
     package com.ityc.service;
     
     import com.ityc.config.SpringConfig;
     import com.ityc.domain.Book;
     import org.junit.Test;
     import org.junit.runner.RunWith;
     import org.springframework.beans.factory.annotation.Autowired;
     import org.springframework.test.context.ContextConfiguration;
     import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
     
     import java.util.List;
     
     @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> bookAll = bookService.getALL();
             System.out.println(bookAll);
         }
     }
     

   • conroller

     • 表现层接口测试（PostMan）

       package com.ityc.controller;
       
       
       import com.ityc.domain.Book;
       import com.ityc.service.BookService;
       import org.apache.ibatis.annotations.Delete;
       import org.springframework.beans.factory.annotation.Autowired;
       import org.springframework.stereotype.Controller;
       import org.springframework.web.bind.annotation.*;
       
       import java.util.List;
       
       //基于Restful的controller开发
       @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();
           }
       
       }
       
       

     • web配置类

       package com.ityc.config;
       
       import org.springframework.web.filter.CharacterEncodingFilter;
       import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
       import org.springframework.web.servlet.support.AbstractDispatcherServletInitializer;
       
       import javax.servlet.Filter;
       
       public class SelectConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
       
           //根配置
           protected Class<?>[] getRootConfigClasses() {
               return new Class[]{SpringConfig.class};
           }
       
           //专门应对web请求的处理
           //这里创建的容器对象与上方的容器对象不是同一个
           protected Class<?>[] getServletConfigClasses() {
               return new Class[]{SpringMvcConfig.class};
           }
       
           protected String[] getServletMappings() {
               return new String[]{"/"};
           }
       
           //POST提交乱码处理
           @Override
           protected Filter[] getServletFilters() {
               CharacterEncodingFilter filter = new CharacterEncodingFilter();
               filter.setEncoding("UTF-8");
               return new Filter[]{filter};
           }
       }
       
       

---

表现层数据封装

• 前端接收数据格式——创建结果模型类，封装数据到data属性中
• 前端接收数据格式——封装操作结果到code属性中
• 前端接收数据格式——封装特殊消息到message（msg）属性中

设置统一数据返回结果类

//Result类中的字段不是固定的，可以根据需要自行增减
//提供若干个构造方法，方便操作
package com.ityc.controller;

public class Result {
    private Object data;
    private Integer code;
    private String msg;

    public Result() {
    }

    public Result( Integer code,Object data, String msg) {
        this.data = data;
        this.code = code;
        this.msg = msg;
    }

    public Result( Integer code,Object data) {
        this.data = data;
        this.code = code;
    }



    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    public Integer getCode() {
        return code;
    }

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

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

定义code类

package com.ityc.controller;

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;


}

优化Controller

package com.ityc.controller;


import com.ityc.domain.Book;
import com.ityc.service.BookService;
import org.apache.ibatis.annotations.Delete;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@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);
        String msg= flag?"删除成功":"数据为空，删除失败";
        return new Result(flag?Code.DELETE_OK:Code.DELETE_ERR,flag,msg);
    }

    @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?"查询成功":"数据为空，查询失败";
        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?"查询成功":"数据为空，查询失败";
        return new Result(code,bookList,msg);
    }

}

优化后的返还结果

注：

表现层数据封装，通过Result与Code类配合业业务，将数据整理成统一格式，反馈给前端页面，再由前端页面的书写人员进行统一解析。

---

异常处理器

异常处理

出现异常现象的常见位置与常见诱因如下

• 框架内部抛出的异常：因使用不合规导致
• 数据层抛异常：因外部服务器故障导致（例：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：遍历业务书写操作，导致索引异常）
• 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）

思考：各个层级均出现异常，异常处理代码书写在哪一层？

• 所有的异常均抛出到表现层进行处理

  1. 表现层处理异常，每个方法中单独书写，代码书写量巨大，且意义不强，如何解决？——AOP思想

  2. SpringMVC为我们提供了异常处理器，来为我们集中的，统一的处理项目中的异常。

     package com.ityc.controller;
     
     import org.springframework.web.bind.annotation.ControllerAdvice;
     import org.springframework.web.bind.annotation.ExceptionHandler;
     import org.springframework.web.bind.annotation.RestController;
     import org.springframework.web.bind.annotation.RestControllerAdvice;
     
     //Rest风格开发的控制器类做增强，本注解自带@ResponseBody注解与@Component注解，具备对应的功能
     @RestControllerAdvice
     public class ProjectExceptionAdvice {
         //写一个方法用于处理异常
         
         //设置拦截处理的异常类型
         @ExceptionHandler(Exception.class)
         public Result doException(Exception ex){
             System.out.println("异常出来吧，别藏了");
             return new Result(666,null,"异常出现了");
         }
     }
     
     

---

项目异常处理方案

项目异常分类

• 业务异常（BusinessException）

  • 不规范用户行为操作产生的异常

    • 处理：发送对应消息传递给用户，提醒规范操作

  • 规范的用户行为产生的异常

• 系统异常(SystemException)

  • 项目运行的过程中可预计且无法避免的异常
    • 处理：发送固定的消息给用户，安抚用户
    • 发送特定信息给运维人员，提醒维护
    • 记录日志

• 其他异常(Exception)

  • 编程人员未预期到的异常
    • 处理：发送固定的消息给用户，安抚用户
    • 发送特定消息给编程人员，提醒维护（纳入预期范围）
    • 记录日志

处理

1. 自定义项目系统级异常

   package com.ityc.exception;
   
   public class SystemException extends RuntimeException{
       private Integer 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;
       }
       -
       public Integer getCode() {
           return code;
       }
   
       public void setCode(Integer code) {
           this.code = code;
       }
   
   
   }
   
   

2. 自定义项目业务级异常

   package com.ityc.exception;
   
   public class BusinessException extends RuntimeException {
       private Integer 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;
       }
   
       public Integer getCode() {
           return code;
       }
   
       public void setCode(Integer code) {
           this.code = code;
       }
   
       
       public BusinessException(Integer code, String message, Throwable cause) {
           super(message, cause);
           this.code = code;
       }
   }
   
   

3. 自定义异常编码（可持续补充）

   package com.ityc.controller;
   
   public class Code {
   
       public static final Integer SYSTEM_ERR = 50001;
       public static final Integer SYSTEM_TIMEOUT_ERR = 50002;
       public static final Integer BUSINESS_ERR = 50003;
       public static final Integer SYSTEM_UNKNOW_ERR = 59999;
   
   
   }
   

4. 触发自定义异常

                                                                                                
       public Book getById(Integer id) {                                                        
           if (id < 1){                                                                         
               throw new BusinessException(Code.BUSINESS_ERR,"警告，非法操作");                        
           }                                                                                    
           return bookDao.getById(id);                                                          
       }                                                                                        
   

5. 拦截并处理异常

   @RestControllerAdvice
   public class ProjectExceptionAdvice {
   
       @ExceptionHandler(SystemException.class)
       public Result doSystemException(SystemException sex){
           //记录日志
           //发送消息给运维
           //发送邮件给开发人员,sex对象发给开发人员
           return new Result(sex.getCode(),null,sex.getMessage());
       }
   
       @ExceptionHandler(BusinessException.class)
       public Result doBusinessException(BusinessException bex){
           //记录日志
           //发送消息给运维
           //发送邮件给开发人员
           return new Result(bex.getCode(),null,bex.getMessage());
       }
   
       //写一个方法用于处理异常
       //设置拦截异常类型
   
       @ExceptionHandler(Exception.class)
       public Result doException(Exception ex){
           //记录日志
           //发送消息给运维
           //发送邮件给开发人员,sex对象发给开发人员
           System.out.println("异常出来吧，别藏了");
           return new Result(Code.SYSTEM_UNKNOW_ERR,null,"出现了位置异常，系统繁忙请稍后再试");
       }
   }
   
   

6. 异常处理器效果

   

注：

• 异常处理器
• 自定义异常
• 异常编码
• 自定义消息