springboot项目浏览器报错：There was an unexpected error (type=Not Found, status=404).

左手的ㄟ右手 2022-06-03 08:27 532阅读 0赞

# springboot项目浏览器报错：There was an unexpected error (type=Not Found, status=404). #

## 报错信息 ##

springboot+thymeleaf项目，运行时页面报错信息如下：

This application has no explicit mapping for /error, so you are seeing this as a fallback.
    
    Sat Dec 23 15:25:59 CST 2017
    There was an unexpected error (type=Not Found, status=404).
    No message available

## 解决方法 ##

### 1、引入thymeleaf引擎 ###

查看是否忘记引入了thymeleaf依赖，没有引入则在mawen的pom.xml文件引入，pom.xml文件的thymeleaf引入如下：

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>          
    </dependency>

### 2、检查访问地址是否正确 ###

检查访问地址是否写正确，地址应该为controller的路径加上RequestMapping的路径。  
如下代码的访问地址为：[http://localhost:8080/getUList][http_localhost_8080_getUList]

@Controller
    public class UlevelController {
        @RequestMapping(value="getUList", method=RequestMethod.GET)
        public String getUlevelList() {
            ………………
            return "ulevel/ulevelList";
        }
    }

如下代码的访问地址为：[http://localhost:8080/hhllow/getUList][http_localhost_8080_hhllow_getUList]

@Controller
    @RequestMapping(value="/hhllow")
    public class UlevelController {
        @RequestMapping(value="getUList", method=RequestMethod.GET)
        public String getUlevelList() {
            ………………
            return "ulevel/ulevelList";
        }
    }

这里顺便说明，如果访问的是hello.html，但是hello.html不存在，不是抛出404的错误，而是500的错误，如下信息：

Error resolving template "/hello", template might not exist or might not be accessible by any of the configured Template Resolvers

如果看到如上信息，那么就要检查下模板文件是否存在，以及文件名称是否编写正确了。

### 3、包路径写对 ###

application.java文件的包必须是项目下的父路径，其他类的包路径必须是其子路径，如：  
![路径][SouthEast]

以下是我在其他地方看到的信息  
![引用][SouthEast 1]

参考：[http://412887952-qq-com.iteye.com/blog/2313575][http_412887952-qq-com.iteye.com_blog_2313575]  
[http://quabr.com/36819277/i-keep-getting-this-error-there-was-an-unexpected-error-type-not-found-status][http_quabr.com_36819277_i-keep-getting-this-error-there-was-an-unexpected-error-type-not-found-status]

[http_localhost_8080_getUList]: http://localhost:8080/getUList
[http_localhost_8080_hhllow_getUList]: http://localhost:8080/hhllow/getUList
[SouthEast]: /images/20220603/2b34cc62c06544e8bde46e3dde6b652f.png
[SouthEast 1]: /images/20220603/d6dbc833b6c643b78ae0149faf580941.png
[http_412887952-qq-com.iteye.com_blog_2313575]: http://412887952-qq-com.iteye.com/blog/2313575
[http_quabr.com_36819277_i-keep-getting-this-error-there-was-an-unexpected-error-type-not-found-status]: http://quabr.com/36819277/i-keep-getting-this-error-there-was-an-unexpected-error-type-not-found-status