一、springmvc 整合jsp技术（过时 了解该技术）

1、核心配置

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.view.InternalResourceViewResolver;/*** @author chenqun* @date 2023/3/18 13:07*/
@Configuration
@ComponentScan("com.qizekj.controller")
@EnableWebMvc
public class SpringMVCConfig {/*** 1.@Configuration  定义SpringMVCConfig.xml配置文件* 2.需要将我们的控制类注入到ioc容器 @ComponentScan("com.qizekj.springmvc")* @ComponentScan("com.qizekj.springmvc")将该包下所有的类 注入到IOC容器种* 3.在springmvc原理 所有请求过来先达到DispatcherServlet 分发具体控制类 方法执行** @Configuration* SpringMVCConfig.java   @Configuration* springmvc.xml=== SpringMVCConfig.java**///WebMvcConfigurer@Beanpublic InternalResourceViewResolver resourceViewResolver() {InternalResourceViewResolver internalResourceViewResolver = new InternalResourceViewResolver();//请求视图文件的前缀地址internalResourceViewResolver.setPrefix("/WEB-INF/jsp/");//请求视图文件的后缀internalResourceViewResolver.setSuffix(".jsp");internalResourceViewResolver.setExposeContextBeansAsAttributes(true);return internalResourceViewResolver;}/*** 视图配置* @param registry*/public void configureViewResolvers(ViewResolverRegistry registry) {registry.viewResolver(resourceViewResolver());}public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {configurer.enable();}}

2、定义控制器

package com.qizekj.controller;import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;/*** @author chenqun* @date 2023/3/19 10:24*/
@Controller
public class QizekjJspController {/*** 访问qizekjJsp,就转发到jsp* @return*/@RequestMapping("/qizekjJsp")public String qizekjJsp() {///WEB-INF/jsp/ 目录中查找qizekj.jspreturn "qizekj";}
}

3、定义jsp页面

在webapp 目录下创建 WEB-INF/jsp 目录，存放qizekj.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>



springmvc+jsp

浏览器访问http://localhost:8081/qizekjJsp：

二、spring+springmvc+mybatis整合

1、SSM环境的整合之提供增删改查

1.1、创建数据库表结构

创建数据库qizekj，并创建表：

CREATE TABLE `qizekj_users` (`id` int NOT NULL AUTO_INCREMENT,`name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,`age` int DEFAULT NULL,`addres` varchar(255) DEFAULT NULL,PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=48 DEFAULT CHARSET=utf8mb3;

1.2、整合maven依赖

spring/springmvc/mybatis

4.0.0com.qizekjqizekj-ssm1.0-SNAPSHOTwarqizekj-ssm Maven Webapphttp://www.example.comUTF-81.71.7org.springframeworkspring-webmvc5.2.10.RELEASEorg.mybatismybatis3.5.6org.springframeworkspring-jdbc5.2.10.RELEASEorg.mybatismybatis-spring1.3.0mysqlmysql-connector-java8.0.13com.alibabadruid1.1.16javax.servletjavax.servlet-api3.1.0providedcom.fasterxml.jackson.corejackson-databind2.9.0org.apache.tomcat.maventomcat7-maven-plugin2.18081/

1.3、实体类层

创建 com.mayikt.entity文件夹，创建实体类UserEntity

package com.qizekj.entity;/*** @author chenqun* @date 2023/3/19 11:04*/
public class UserEntity {private Integer id;private String name;private Integer age;private String addres;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public String getAddres() {return addres;}public void setAddres(String addres) {this.addres = addres;}
}

1.4、数据库访问层

创建 com.mayikt.mapper文件夹，创建UserMapper

package com.qizekj.mapper;import com.qizekj.entity.UserEntity;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;/*** @author chenqun* @date 2023/3/19 11:07*/
public interface UserMapper {/*** mybatis 有xml和注解两种方式（sql语句）*/@Insert("INSERT INTO `qizekj`.`qizekj_users` (`id`, `name`, `age`, `addres`) VALUES (#{id}, #{name}, #{age}, #{addres});")int insertUser(UserEntity userEntity);@Delete("delete from qizekj_users where id=#{id}")int deleteById(Integer id);@Update("UPDATE `qizekj`.`qizekj_users` SET `name`=#{name}, `age`=#{age}, `addres`=#{addres} WHERE id=#{id}")int updateUser(UserEntity userEntity);@Select("select * from qizekj_users where id=#{id}")UserEntity getById(Integer id);
}

1.5、业务逻辑层

创建 com.mayikt.service文件夹，创建UserService

package com.qizekj.service;import com.qizekj.entity.UserEntity;
import com.qizekj.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;/*** @author chenqun* @date 2023/3/19 12:22*/
@Service
public class UserService {@Autowiredprivate UserMapper userMapper;public int insertUser(UserEntity userEntity){return userMapper.insertUser(userEntity);};public int deleteById(Integer id){return userMapper.deleteById(id);};public int updateUser(UserEntity userEntity){return userMapper.updateUser(userEntity);};public UserEntity getById(Integer id){return userMapper.getById(id);};
}

1.6、控制层

创建 com.mayikt.controller文件夹，创建UserController

package com.qizekj.controller;import com.qizekj.entity.UserEntity;
import com.qizekj.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;/*** @author chenqun* @date 2023/3/19 12:27*/
@RestController
public class UserController {@Autowiredprivate UserService userService;/*** 根据id查询数据* @param id* @return*/@GetMapping("/getById/{id}")public UserEntity getById(@PathVariable("id") Integer id){return userService.getById(id);};/*** 插入数据* @param userEntity* @return*/@PostMapping("/insertUser")public int insertUser(@RequestBody UserEntity userEntity){return userService.insertUser(userEntity);};/*** 根据id删除数据* @param id* @return*/@DeleteMapping("/deleteById/{id}")public int deleteById(@PathVariable("id") Integer id){return userService.deleteById(id);};/*** 修改数据* @param userEntity* @return*/@PutMapping("/updateUser")public int updateUser(@RequestBody UserEntity userEntity){return userService.updateUser(userEntity);};
}

2、SSM环境的整合之配置整合

2.1、JdbcConfig

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;import javax.sql.DataSource;/*** @author chenqun* @date 2023/3/19 13:05*/
public class JdbcConfig {/*** 定义数据源配置* @return*/@Beanpublic DataSource dataSource() {DruidDataSource druidDataSource = new DruidDataSource();druidDataSource.setDriverClassName("com.mysql.jdbc.Driver");druidDataSource.setUrl("jdbc:mysql://localhost:3306/qizekj?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT");druidDataSource.setUsername("root");druidDataSource.setPassword("123456");return druidDataSource;}/*** 整合事务* @param dataSource* @return*/@Beanpublic PlatformTransactionManager platformTransactionManager(@Autowired DataSource dataSource) {DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();dataSourceTransactionManager.setDataSource(dataSource);return dataSourceTransactionManager;}
}

2.2、MybatisConfig

import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;import javax.sql.DataSource;/*** @author chenqun* @date 2023/3/19 13:06*/
public class MybatisConfig {/*** mybatis相关配置* @param dataSource* @return*/@Beanpublic SqlSessionFactoryBean sqlSessionFactory(@Autowired DataSource dataSource) {SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();sqlSessionFactoryBean.setDataSource(dataSource);// 实体层包sqlSessionFactoryBean.setTypeAliasesPackage("com.qizekj.entity");return sqlSessionFactoryBean;}
}

2.3、SpringConfig

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.transaction.annotation.EnableTransactionManagement;/*** @author chenqun* @date 2023/3/19 13:06*/
@Configuration
@ComponentScan({"com.qizekj.service"})
@MapperScan("com.qizekj.mapper")
//开启事务
@EnableTransactionManagement
@Import({MybatisConfig.class, JdbcConfig.class})
public class SpringConfig {//SpringConfig.xml 扫包范围//@MapperScan() mybatis 扫包范围//@Import({MybatisConfig.class, JdbcConfig.class}) 引入MybatisConfig和JdbcConfig配置类
}

2.4、SpringMVCConfig

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;/*** @author chenqun* @date 2023/3/19 13:06*/
@EnableWebMvc  //开启springmvc
@Configuration
@ComponentScan("com.qizekj.controller")  //配置springmvc扫包范围
public class SpringMVCConfig {
}

2.5、ServletConfig

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;/*** @author chenqun* @date 2023/3/19 13:06*/
public class ServletConfig extends AbstractAnnotationConfigDispatcherServletInitializer {/*** 加载Spring相关配置* @return*/protected Class[] getRootConfigClasses() {return new Class[]{SpringConfig.class};}/*** 加载SpringMVC相关配置* @return*/protected Class[] getServletConfigClasses() {return new Class[]{SpringMVCConfig.class};}/*** 拦截所以请求* @return*/protected String[] getServletMappings() {return new String[]{"/"};}
}

2.6、测试增删改查方法

• 使用postman测试插入方法，插入成功：

• 使用postman测试查询方法，查询成功：

• 使用postman测试修改方法，修改成功：
  
• 使用postman测试删除方法，删除成功：

3、接口响应状态码

统一规范返回数据的格式，此处以json格式为例。返回数据应包含：返回状态码、返回状态信息、具体数据。

格式规范如下：

• 例如成功查询到数据，则显示：

{"code":"200","msg":"ok","data": {"name":"qizekj","age":32}
}

前端 ajax 技术：

if(code==200){"data": {"name":"qizekj","age":32}
}

• 例如没有查询到数据，则显示：

{"code":"500","msg":"fail","data": {}
}

• 例如新增数据成功，则显示：

{"code":"200","msg":"插入成功","data": {}
}

• 例如新增数据失败，则显示：

{"code":"500","msg":"插入失败","data": {}
}

前端 ajax 技术：

if（code==200）{alert(" "msg":"插入成功"")
}

• Api Code状态码：

• 封装接口响应状态码：

import java.util.HashMap;/*** @author chenqun* @date 2023/3/19 19:41*/
public class BaseController {/*** 提供处理请求响应成功的情况下* @param data* @return*/public HashMap setResultOk(Object data) {return setResult(200, "ok", data);}public HashMap setResultSuccess(String msg) {return setResult(200, msg, null);}/*** 提供处理请求失败情况下** @param msg* @return*/public HashMap setResultError(String msg) {return setResult(500, msg, null);}/*** @param code code 200 处理成功 500 处理失败* @param msg  响应错误内容* @param data 响应的数据* @return*/public HashMap setResult(Integer code, String msg, Object data) {HashMap result = new HashMap<>();result.put("code", code);result.put("msg", msg);result.put("data", data);return result;}
}
}

• 改造前面的controller里的查询和新增方法：
  继承BaseController类，并改造查询和新增方法。

import com.qizekj.entity.UserEntity;
import com.qizekj.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import java.util.Map;/*** @author chenqun* @date 2023/3/19 12:27*/
@RestController
public class UserController2 extends BaseController{@Autowiredprivate UserService userService;/*** 根据id查询数据* @param id* @return*/@GetMapping("/getById/{id}")public Map getById(@PathVariable("id") Integer id){// 定义返回数据的结果，验证参数是否合法if(id == null){return setResultError("id is null");}// 根据id查询数据UserEntity userEntity = userService.getById(id);if(userEntity == null){return setResultError("根据该id没有查询到数据");}return setResultOk(userEntity);};/*** 插入数据* @param userEntity* @return*/@PostMapping("/insertUser")public Map insertUser(@RequestBody UserEntity userEntity){return userService.insertUser(userEntity)>0 ? setResultSuccess("插入成功") : setResultError("插入失败");};
}

4、整合全局捕获异常

• 创建全局捕获异常配置类
  当系统发生错误时，统一将系统错误日志 返回输出。

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;import javax.servlet.http.HttpServletRequest;
import java.util.Map;@ControllerAdvice
public class GlobalExceptionHandler extends BaseController {@ResponseBody@ExceptionHandler(value = Exception.class)public Map handleException(HttpServletRequest h, Exception e) {System.out.println("自定义异常：" + e);return setResultError("系统发生了错误!");}
}

• 测试：
  编写测试controller：

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** @author chenqun* @date 2023/3/19 20:01*/
@RestController
public class ExceptionController {@RequestMapping("/getException")public String getException(Integer num){int i = 1/num;return "qizekj:" + num;}
}

未配置全局捕获异常配置类之前：

配置全局捕获异常配置类后的效果：