验证Controller：500错误

Question

现在评论区找了一遍大家的解决方法，但是要么不适合我，要么没有成效，所有还是请老师帮忙看一下是是什么错误

在Dao验证和Service验证都没有问题

因此贴一下spring-web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
    <!-- 配置SpringMVC -->
    <!-- 1.开启SpringMVC注解模式 -->
    <mvc:annotation-driven />

    <!-- 2.静态资源默认servlet配置 (1)加入对静态资源的处理：js,gif,png (2)允许使用"/"做整体映射 -->
    <mvc:resources mapping="/resources/**" location="/resources" />
    <mvc:default-servlet-handler />

    <!-- 3.定义视图解析器 -->
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/html/"></property>
        <property name="suffix" value=".html"></property>
    </bean>
    <!-- 文件上传解析器 -->
    <bean id="multipartResolver"
          class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="utf-8"></property>
        <!-- 1024 * 1024 * 20 = 20M -->
        <property name="maxUploadSize" value="20971520"></property>
        <property name="maxInMemorySize" value="20971520"></property>
    </bean>

    <!-- 4.扫描web相关的bean -->
    <context:component-scan base-package="com.imooc.o2o.web" />
    <!-- 5.权限拦截器 -->
</beans>

其中，/rescources/报红色

由于我是idea环境，因此访问url时不需要加上o2o，访问http://localhost:8080/superadmin/listarea结果如下：

我的tomcat版本为9.0

AreaController如下：除了list变量名修改为了areaList，其余都一样，修改成list也是一样的错误，因此应该与此无关

package com.imooc.o2o.web.superadmin;


import com.imooc.o2o.entity.Area;
import com.imooc.o2o.service.AreaService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 想要调用Controller层的方法，就需要为其添加一个url路径
 */
@Controller
@RequestMapping("/superadmin")
public class AreaController {
    @Autowired
    private AreaService areaService;
    /**
     * 将返回值自动转为json对象返回给前端@RequestBody
     */
    @RequestMapping(value = "/listarea",method = RequestMethod.GET)
    @ResponseBody
    public Map<String,Object> listArea()
    {
        Map<String,Object> modelMap= new HashMap<String, Object>();
        List<Area> areaList=new ArrayList<Area>();
        try
        {
            areaList=areaService.getAreaList();
            modelMap.put("rows",areaList);
            modelMap.put("total",areaList.size());
        }
        catch (Exception e)
        {
            e.printStackTrace();
            modelMap.put("success",false);
            modelMap.put("errMsg",false);
        }

        return modelMap;
    }
}

Answer 1

提问者 zoyoxn 2021-07-21 16:47:14

我的pom.xml文件，对比视频和源码几次了，除了注释掉一些暂时未用到的，我觉着是没问题的

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>Store</artifactId>
  <version>1.0-SNAPSHOT</version>
  <properties>
    <spring.version>5.1.8.RELEASE</spring.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.12</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.2</version>
      <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>1.2.3</version>
    </dependency>
    <!-- Spring -->
    <!-- 1)包含Spring 框架基本的核心工具类。Spring 其它组件要都要使用到这个包里的类，是其它组件的基本核心 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>5.2.11.RELEASE</version>
    </dependency>
    <!-- 2)这个jar 文件是所有应用都要用到的，它包含访问配置文件、创建和管理bean 以及进行Inversion of Control
        / Dependency Injection（IoC/DI）操作相关的所有类。如果应用只需基本的IoC/DI 支持，引入spring-core.jar
        及spring-beans.jar 文件就可以了。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 3)这个jar 文件为Spring 核心提供了大量扩展。可以找到使用Spring ApplicationContext特性时所需的全部类，JDNI
        所需的全部类，instrumentation组件以及校验Validation 方面的相关类。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 4) 这个jar 文件包含对Spring 对JDBC 数据访问进行封装的所有类。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 5) 为JDBC、Hibernate、JDO、JPA等提供的一致的声明式和编程式事务管理。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 6)Spring web 包含Web应用开发时，用到Spring框架时所需的核心类，包括自动载入WebApplicationContext特性的类、Struts与JSF集成类、文件上传的支持类、Filter类和大量工具辅助类。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 7)包含SpringMVC框架相关的所有类。 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 8)Spring test 对JUNIT等测试框架的简单封装 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
      <scope>test</scope>
    </dependency>
    <!-- Servlet web -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>
    <!-- json解析 -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.9</version>
    </dependency>
    <!-- Map工具类 对标准java Collection的扩展 spring-core.jar需commons-collections.jar -->
    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.2.2</version>
    </dependency>
    <!-- DAO: MyBatis -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.1</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>2.0.1</version>
    </dependency>
    <!-- 数据库 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.23</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
    <!--        <dependency>-->
    <!--            <groupId>c3p0</groupId>-->
    <!--            <artifactId>c3p0</artifactId>-->
    <!--            <version>0.9.1.2</version>-->
    <!--        </dependency>-->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.4</version>
    </dependency>

    <!-- 图片处理 -->
    <!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->
    <dependency>
      <groupId>net.coobird</groupId>
      <artifactId>thumbnailator</artifactId>
      <version>0.4.8</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.2</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.2.11.RELEASE</version>
      <scope>compile</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.github.penggle/kaptcha -->
    <!--        <dependency>-->
    <!--            <groupId>com.github.penggle</groupId>-->
    <!--            <artifactId>kaptcha</artifactId>-->
    <!--            <version>2.3.2</version>-->
    <!--        </dependency>-->
            <dependency>
                <groupId>commons-fileupload</groupId>
                <artifactId>commons-fileupload</artifactId>
                <version>1.3.2</version>
            </dependency>
    <!--        &lt;!&ndash; redis客户端:Jedis &ndash;&gt;-->
    <!--        <dependency>-->
    <!--            <groupId>redis.clients</groupId>-->
    <!--            <artifactId>jedis</artifactId>-->
    <!--            <version>2.9.0</version>-->
    <!--        </dependency>-->
  </dependencies>
  <build>
    <finalName>o2o</finalName>
    <plugins>
      <plugin>
        <!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-compiler-plugin -->
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.6.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
          <encoding>UTF8</encoding>
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>

• 热心市民小马 #1

  spring-web的配置文件里资源映射应该写成    <mvc:resources mapping="/resources/**" location="/resources/"/> 你第二个resources后面少了个斜杠，最后再看看web.xml的配置，是不是拦截了所有的请求

• 提问者 zoyoxn 回复 热心市民小马 #2

  resources那里是我报错以后，修改过然后没修改回来，所以不是少了个斜杠的原因^ ^
  
  然后web.xml的话，我也没有修改过，和老师代码是一样的，默认匹配所有请求，应该不存在拦截问题，不过我也不是很清楚，所以我列一下web.xml
  
  ```
  <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                        http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
           version="3.1" metadata-complete="true">
      <display-name>Archetype Created Web Application</display-name>
      <welcome-file-list>
          <welcome-file>aaa.jsp</welcome-file>
          <welcome-file>index.jsp</welcome-file>
      </welcome-file-list>
      <servlet>
          <servlet-name>spring-dispatcher</servlet-name>
          <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
          <init-param>
              <param-name>contextConfigLocation</param-name>
              <param-value>classpath:/spring/spring-*.xml</param-value>
          </init-param>
      </servlet>
      <servlet-mapping>
          <servlet-name>spring-dispatcher</servlet-name>
          <!--默认匹配所有的请求-->
          <url-pattern>/</url-pattern>
      </servlet-mapping>
  </web-app>
  
  ```

• 翔仔 回复 热心市民小马 #3

  感谢同学的热心答复，这个问题应该是缺少 spring-webmvc  这个jar包，需要同学在pom.xml里面引入

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