使用IDEA搭建一个Spring + AOP (权限管理 ) + Spring MVC + Mybatis的Web项目 (零配置文件)...

怼烎@ 2022-01-06 22:27 227阅读 0赞

# 前言： #

除了mybatis 不是零配置，有些还是有xml的配置文件在里面的。

### 注解是Spring的一个构建的一个重要手段，减少写配置文件，下面解释一下一些要用到的注解： ###

@Configuration 作用于类上面，声明当前类是一个配置类（相当于一个Spring的xml文件）  
@ComponentScan(“xxx”) 作用于类上面，自动扫描xxx包名下所有使用@Service、@Component、@Repository和@Controller的类，并注册为Bean  
@Bean 作用与类和方法上，相当于Spring配置文件bean节点  
@EnableWebMvc 作用于类，开启一些默认配置，如一些ViewResolver或者MessageConverter  
@RequestMapping 作用于类、方法，配置URL和方法之间的映射  
@RequestBody 作用于参数前，允许request的参数在request体中，而不是在直接链接在地址后面  
@ResponseBody 作用于返回值、方法上，支持将返回值放在response体中，而不是返回一个页面。  
@RequestParam 作用于参数前，将form的对应name值映射到当前参数中。

###  这里我就不从一开始了。 ###

### pom.xml ###

[\+  ][ ]

### 项目结构： ###

![1443576-20181220203246779-1769607353.png][]

先把上面的包，依次创建好，（webapp文件夹中的WEB-INF所有文件全部删掉）

### 我们从 config (配置) 包开始吧。 ###

![1443576-20181220203455816-241827787.png][]

RootConfig类 (类似于spring-root.xml配置文件一样)

![复制代码][copycode.gif]

1 package com.oukele.config.spring;
     2 
     3 import org.springframework.context.annotation.ComponentScan;
     4 import org.springframework.context.annotation.Configuration;
     5 import org.springframework.context.annotation.Import;
     6 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
     7 
     8 @Configuration//声明当前类 是一个 配置类
     9 @ComponentScan(basePackages = "com.oukele.dao")//扫描 dao包 使用spring 注解的接口
    10 @Import({SpringDaoConfig.class,SpringServlet.class})//导入其他配置
    11 public class RootConfig {
    12 
    13 }

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SpringWebConfig类 (相当于 spring-web.xml )

![复制代码][copycode.gif]

package com.oukele.config.mvc;
    
    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.EnableAspectJAutoProxy;
    import org.springframework.web.servlet.config.annotation.EnableWebMvc;
    import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
    
    @Configuration//声明当前类是配置类 类似于 spring-web.xml 文件
    @EnableWebMvc// 若无此注解 WebMvcConfigurer 无效
    @ComponentScan(basePackages = {"com.oukele.controller","com.oukele.aspect"})//扫描控制层 和切面 包
    @EnableAspectJAutoProxy// 激活 切面 代理
    public class SpringWebConfig implements WebMvcConfigurer {
        //注册静态资源，没注册的话，网站是访问不了的
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            registry.addResourceHandler("/css/**").addResourceLocations("/WEB-INF/css/");
        }
    
    }

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SpringDaoConfig类 (  配置 数据源  )

![复制代码][copycode.gif]

1 package com.oukele.config.spring;
     2 
     3 import com.mchange.v2.c3p0.ComboPooledDataSource;
     4 import org.mybatis.spring.SqlSessionFactoryBean;
     5 import org.mybatis.spring.mapper.MapperScannerConfigurer;
     6 import org.springframework.beans.factory.annotation.Autowired;
     7 import org.springframework.context.EnvironmentAware;
     8 import org.springframework.context.annotation.Bean;
     9 import org.springframework.context.annotation.Configuration;
    10 import org.springframework.context.annotation.PropertySource;
    11 import org.springframework.core.env.Environment;
    12 import org.springframework.core.io.ClassPathResource;
    13 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
    14 
    15 import javax.sql.DataSource;
    16 import java.beans.PropertyVetoException;
    17 import java.io.IOException;
    18 
    19 @Configuration
    20 @PropertySource(value = "classpath:jdbc.properties")//加载资源文件
    21 public class SpringDaoConfig implements EnvironmentAware {//数据层
    22 
    23     @Autowired
    24     private Environment env;
    25 
    26     @Override
    27     public void setEnvironment(Environment environment) {
    28         this.env = environment;
    29     }
    30 
    31     //配置数据源
    32     @Bean
    33     public DataSource dataSource() throws PropertyVetoException {
    34         ComboPooledDataSource dataSource = new ComboPooledDataSource();
    35         dataSource.setDriverClass(env.getProperty("jdbc.driver"));
    36         dataSource.setJdbcUrl(env.getProperty("jdbc.url"));
    37         dataSource.setUser(env.getProperty("jdbc.user"));
    38         dataSource.setPassword(env.getProperty("jdbc.password"));
    39         return dataSource;
    40     }
    41     //配置 mybatis
    42     @Bean
    43     public SqlSessionFactoryBean sqlSessionFactoryBean() throws IOException, PropertyVetoException {
    44         SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
    45         PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
    46         factoryBean.setTypeAliasesPackage("com.oukele.entity");//实体类
    47         factoryBean.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));// 映射 sql文件
    48         factoryBean.setConfigLocation(new ClassPathResource("mybatis-config.xml"));//mybatis配置
    49         factoryBean.setDataSource(dataSource());
    50         return factoryBean;
    51     }
    52     // 简化调用 将 dao 放置 容器中  使用：比如
    53     //@Autowired
    54     //xxxMapper xxmaper ;
    55     //也可以在类上面 直接使用 @ComponentScan 扫描接口
    56     @Bean
    57     public MapperScannerConfigurer mapperScannerConfigurer() {
    58         MapperScannerConfigurer configurer = new MapperScannerConfigurer();
    59         configurer.setBasePackage("com.oukele.dao");//扫描接口
    60         configurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBean");
    61         return configurer;
    62     }
    63    
    64 }

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SpringServlet 类 （扫描 ）

![复制代码][copycode.gif]

WebConfig 类 （类似于 web.xml文件）

![复制代码][copycode.gif]

1 package com.oukele.config.web;
     2 
     3 import com.oukele.config.mvc.SpringWebConfig;
     4 import com.oukele.config.spring.RootConfig;
     5 import org.springframework.web.filter.CharacterEncodingFilter;
     6 import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
     7 
     8 import javax.servlet.Filter;
     9 
    10 public class WebConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    11 
    12     @Override
    13     protected Class<?>[] getRootConfigClasses() {// (spring容器) 父容器
    14         return new Class[]{RootConfig.class};
    15     }
    16 
    17     @Override
    18     protected Class<?>[] getServletConfigClasses() {//  (spring mvc容器)  子容器
    19         return new Class[]{SpringWebConfig.class};
    20     }
    21 
    22     @Override
    23     protected String[] getServletMappings() {//映射
    24         return new String[]{"/"};
    25     }
    26 
    27     //设置编码 这里设置好像没有用。。。。。 有解决方案请告诉我，谢谢
    28     @Override
    29     protected Filter[] getServletFilters() {
    30         CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
    31         characterEncodingFilter.setEncoding("UTF-8");
    32         return new Filter[]{characterEncodingFilter};
    33     }
    34 }

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###  Controller 包 里面的类 ###

![1443576-20181220211340204-216791428.png][]

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1 package com.oukele.controller;
     2 
     3 import com.oukele.entity.User;
     4 import com.oukele.servlet.UserServlet;
     5 import org.springframework.beans.factory.annotation.Autowired;
     6 import org.springframework.web.bind.annotation.*;
     7 import org.springframework.web.context.WebApplicationContext;
     8 
     9 import javax.servlet.http.HttpSession;
    10 import java.util.HashMap;
    11 import java.util.Objects;
    12 
    13 @RestController
    14 public class LoginController {
    15 
    16     @Autowired
    17     private WebApplicationContext webApplicationContext;
    18 
    19     @Autowired
    20     private UserServlet userServlet;
    21 
    22     @RequestMapping(path = "/login/{name}/{password}", method = RequestMethod.GET,produces = "application/json;charset=utf-8")
    23     public String login(@PathVariable("name") String name, @PathVariable("password") String password, HttpSession session) {
    24         User user = new User();
    25         user.setUserName(name);
    26         user.setPassword(password);
    27         session.setAttribute("username",user);//存入session中
    28         Boolean aBoolean = userServlet.checkUser(user);
    29         
    30         if(aBoolean){
    31             return "{\"msg\":\"登入成功\"}";
    32         }
    33 
    34         return "{\"msg\":\"登入失败\"}";
    35     }
    36 
    37     @GetMapping(path = "/Ioc")
    38     public HashMap<String, String[]> getAllInfo() {
    39 
    40         return new HashMap<String, String[]>() {
          {
    41             put("子容器", webApplicationContext.getBeanDefinitionNames());
    42             put("父容器", Objects.requireNonNull(webApplicationContext.getParent().getBeanDefinitionNames()));
    43         }};
    44 
    45     }
    46 
    47 }

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###  dao包中的接口 ###

![1443576-20181220211430097-287025927.png][]

![复制代码][copycode.gif]

1 package com.oukele.dao;
     2 
     3 import com.oukele.entity.User;
     4 import org.apache.ibatis.annotations.Select;
     5 import org.springframework.stereotype.Repository;
     6 
     7 @Repository
     8 public interface UserMapper {
     9 
    10     //使用xml配置文件
    11     int check(User user);
    12     //使用注解
    13     @Select("select count(*) from user where userName = #{userName} and password = #{password}")
    14     int check1(User user);
    15 
    16 }

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### entity包中的类 ###

![1443576-20181220230952323-447513318.png][]

![复制代码][copycode.gif]

1 package com.oukele.entity;
     2 
     3 public class User {
     4     private String userName;
     5     private String password;
     6 
     7     public String getUserName() {
     8         return userName;
     9     }
    10 
    11     public void setUserName(String userName) {
    12         this.userName = userName;
    13     }
    14 
    15     public String getPassword() {
    16         return password;
    17     }
    18 
    19     public void setPassword(String password) {
    20         this.password = password;
    21     }
    22 
    23     @Override
    24     public String toString() {
    25         return "User{" +
    26                 "userName='" + userName + '\'' +
    27                 ", password='" + password + '\'' +
    28                 '}';
    29     }
    30 }

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### servlet包中的类 ###

![复制代码][copycode.gif]

1 package com.oukele.servlet;
     2 
     3 import com.oukele.dao.UserMapper;
     4 import com.oukele.entity.User;
     5 import org.springframework.beans.factory.annotation.Autowired;
     6 import org.springframework.stereotype.Service;
     7 
     8 @Service
     9 public class UserServlet {
    10 
    11     @Autowired
    12     private UserMapper userMapper;
    13 
    14     public Boolean checkUser(User user){
    15         //根据传进来的参数，去数据库查找用户
    16         int result = userMapper.check(user);
    17         //如果查回来的结果不为零，说明数据库中有该用户，让他登陆，否则不让他登陆
    18         if( result > 0 ){
    19             return true;
    20         }
    21         return false;
    22     }
    23 
    24 }

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###  resources 目录 ###

![1443576-20181220231237858-349083277.png][]

### jdbc.properties 资源文件 ###

1 jdbc.driver=org.mariadb.jdbc.Driver
    2 jdbc.url=jdbc:mariadb://localhost:3306/test
    3 jdbc.user=oukele
    4 jdbc.password=oukele

### mybatis-config.xml 配置文件 ###

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1 <?xml version="1.0" encoding="UTF-8" ?>
     2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
     3 <configuration>
     4     <settings>
     5         
     6         <setting name="useGeneratedKeys" value="true"/>
     7         
     8         <setting name="useColumnLabel" value="true"/>
     9         
    10         <setting name="mapUnderscoreToCamelCase" value="true"/>
    11     </settings>
    12 </configuration>

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### mapper文件中的 UserMapper.xml 配置文件 ###

![复制代码][copycode.gif]

1 <?xml version="1.0" encoding="UTF-8"?>
     2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
     3 
     4 <mapper namespace="com.oukele.dao.UserMapper">
     5 
     6     <select id="check" parameterType="com.oukele.entity.User" resultType="java.lang.Integer">
     7         select count(*) from user where userName = #{userName} and password = #{password}
     8     </select>
     9 
    10 </mapper>

![复制代码][copycode.gif]

好，到这里我们启动了试一下效果了，（我现在的数据库没有数据库的）

配置Tomcat 启动

运行效果：

![1443576-20181220232302482-940669593.gif][]

## 那么到这里就开始我们的 权限管理 了，激动。。。。。。 ##

了解一下 AspectJ ？ 地址：[https://www.cnblogs.com/nongzihong/p/10190866.html][https_www.cnblogs.com_nongzihong_p_10190866.html][  
][Link 1]

先创建一个包 aspect ( 切面 )

![1443576-20181220233935521-544755038.png][]

### UserPowerAdvice 类 (切面类) ###

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      <code>package</code>&nbsp; 
      <code>com.oukele.aspect;</code> 
     </div> 
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      <code>import</code>&nbsp; 
      <code>com.oukele.dao.UserMapper;</code> 
     </div> 
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      <code>import</code>&nbsp; 
      <code>com.oukele.entity.User;</code> 
     </div> 
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      <code>import</code>&nbsp; 
      <code>org.aspectj.lang.ProceedingJoinPoint;</code> 
     </div> 
     <div> 
      <code>import</code>&nbsp; 
      <code>org.aspectj.lang.annotation.Around;</code> 
     </div> 
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      <code>org.aspectj.lang.annotation.Pointcut;</code> 
     </div> 
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      <code>org.springframework.beans.factory.annotation.Autowired;</code> 
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      <code>org.springframework.stereotype.Component;</code> 
     </div> 
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      <code>javax.servlet.http.HttpSession;</code> 
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       &nbsp; 
     </div> 
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      <code>@Component</code> 
      <code>//注入容器</code> 
     </div> 
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      <code>@Aspect</code> 
      <code>//声明这是一个 切面类</code> 
     </div> 
     <div> 
      <code>public</code>&nbsp; 
      <code>class</code>&nbsp; 
      <code>UserPowerAdvice { </code> 
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      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>@Autowired</code> 
     </div> 
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      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>HttpSession session;</code> 
     </div> 
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       &nbsp; 
     </div> 
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      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>@Autowired</code> 
     </div> 
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      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>UserMapper userMapper;</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//切点</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>@Pointcut</code> 
      <code>(</code> 
      <code>"execution(* com.oukele.controller.*.login(..))"</code> 
      <code>)</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>public</code>&nbsp; 
      <code>void</code>&nbsp; 
      <code>power() { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>;</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//环绕通知</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>@Around</code> 
      <code>(</code> 
      <code>"power()"</code> 
      <code>)</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>public</code>&nbsp; 
      <code>Object seeStatus(ProceedingJoinPoint joinPoint) { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>try</code>&nbsp; 
      <code>{ </code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>// ......前环绕通知 --&gt; 在原方法还没有执行前先执行</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>Object o = joinPoint.proceed();</code> 
      <code>//执行被代理的方法&nbsp; //环绕通知 能覆盖原方法</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>// .......后环绕通知 --&gt; 在原方法执行后执行</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//从session中取出 存储的信息</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>User user = (User) session.getAttribute(</code> 
      <code>"username"</code> 
      <code>);</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//作为 演示 这里的逻辑就随意一写哈</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//如果用户名不为空和密码不为空，去数据库查询，这里呢 我数据库只有用户名和密码</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//所以 我这里 如果 用户名为 oukele 则为管理管 否则都是普通用户</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>if</code>&nbsp; 
      <code>(!user.getUserName().isEmpty() &amp;&amp; !user.getPassword().isEmpty()) { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>//去数据库中查询,结果大于 0 则存在用户 否则</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>int</code>&nbsp; 
      <code>result = userMapper.check1(user);</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>if</code>&nbsp; 
      <code>(result &gt;&nbsp;</code> 
      <code>0</code> 
      <code>) { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>if</code>&nbsp; 
      <code>(user.getUserName().equals(</code> 
      <code>"oukele"</code> 
      <code>)) { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>return</code>&nbsp; 
      <code>"{\"msg\":\"该用户 "</code>&nbsp; 
      <code>+ user.getUserName() +&nbsp;</code> 
      <code>" 是 管理员\"}"</code> 
      <code>;</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}&nbsp;</code> 
      <code>else</code>&nbsp; 
      <code>{ </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>return</code>&nbsp; 
      <code>"{\"msg\":\"该用户 "</code>&nbsp; 
      <code>+ user.getUserName() +&nbsp;</code> 
      <code>" 不是 管理员\"}"</code> 
      <code>;</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}&nbsp;</code> 
      <code>else</code>&nbsp; 
      <code>{ </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>return</code>&nbsp; 
      <code>"{\"msg\":\"用户不存在。。\"}"</code> 
      <code>;</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}&nbsp;</code> 
      <code>else</code>&nbsp; 
      <code>{ </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>return</code>&nbsp; 
      <code>"{\"msg\":\"用户名或者密码为空。。\"}"</code> 
      <code>;</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}&nbsp;</code> 
      <code>catch</code>&nbsp; 
      <code>(Throwable throwable) { </code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>throwable.printStackTrace();</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>return</code>&nbsp; 
      <code>null</code> 
      <code>;</code> 
     </div> 
     <div> 
      <code>&nbsp;&nbsp;&nbsp;&nbsp;</code> 
      <code>}</code> 
     </div> 
     <div>
       &nbsp; 
     </div> 
     <div> 
      <code>}</code> 
     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

###  在SpringWebConfig 类 加上 @EnableAspectJAutoProxy 注解 和 扫描 aspect 包 ###

![1443576-20181221001507463-1306007490.png][]

### 运行效果（数据库没有数据的情况下）： ###

![1443576-20181221003220550-1762603415.gif][]

### 在有数据的情况下的效果： ###

![1443576-20181221003543048-140971220.gif][]

####  源码下载地址：[https://github.com/nongzihong/Hello\_wrold][https_github.com_nongzihong_Hello_wrold] ####

转载于:https://www.cnblogs.com/nongzihong/p/10190748.html

[ ]: https://www.cnblogs.com/oukele/p/10152176.html#
[1443576-20181220203246779-1769607353.png]: /images/20211227/e1e493fddf464599bc9c9de7ce1ee564.png
[1443576-20181220203455816-241827787.png]: /images/20211227/bf7f1c4e5a034f09bab42b557f76cb12.png
[copycode.gif]: /images/20211227/f846989cc5464bca9eea0faa7c30c0eb.png
[1443576-20181220211340204-216791428.png]: /images/20211227/3d2681519f464e059b5f5b15c7c8c1e7.png
[1443576-20181220211430097-287025927.png]: /images/20211227/024ff09392754389b32e04a3acbb368e.png
[1443576-20181220230952323-447513318.png]: /images/20211227/c5d7f4171ea64be6acd8f3a249d4dafe.png
[1443576-20181220231237858-349083277.png]: /images/20211227/9b975f9de3d746998da6acd1d9a91dc2.png
[1443576-20181220232302482-940669593.gif]: /images/20211227/4bedf6ed5216467db08cb9987da19d1b.png
[https_www.cnblogs.com_nongzihong_p_10190866.html]: https://www.cnblogs.com/nongzihong/p/10190866.html
[Link 1]: https://www.cnblogs.com/oukele/p/10137958.html
[1443576-20181220233935521-544755038.png]: /images/20211227/b3aee9b167e8452caf75f73efa661c91.png
[1443576-20181221001507463-1306007490.png]: /images/20211227/9bfaf07a607d4207812bcb7099356571.png
[1443576-20181221003220550-1762603415.gif]: /images/20211227/21548a6b54e141e09bfca12178c771b3.png
[1443576-20181221003543048-140971220.gif]: /images/20211227/41fb51490394482fbe6238e19505ffd6.png
[https_github.com_nongzihong_Hello_wrold]: https://github.com/nongzihong/Hello_wrold