There was an unexpected error (type=Not Found, status=404).

╰半橙微兮° 2021-09-23 09:56 460阅读 0赞

使用spring项目访问后台接口时返回了这个错误。

Whitelabel Error Page
    This application has no explicit mapping for /error, so you are seeing this as a fallback.
    
    Fri Oct 25 17:31:57 CST 2019
    There was an unexpected error (type=Not Found, status=404).
    No message available

后台是这样

@Controller
    @EnableAutoConfiguration
    @RequestMapping("/test")
    public class TestController { 
    	
    	@RequestMapping("/testMethod")
    	public JSON testMethod() { 
    		System.out.println("12345");
    		Map res = new HashMap();
    		res.put("data", 321);
    		return JSONObject.fromObject(res);
    	}
    	
    }

通过后台查看发现，请求确实收到了，但是依然报404 。最后发现是没有设置@ResponseBody。

解决方法，方法上面加上注解@ResponseBody，或者将类的注解@Controller改为@RestController。

@RestController = @Controller + @ResponseBody

修改后的代码

@Controller
    @EnableAutoConfiguration
    @RequestMapping("/test")
    public class TestController { 
    	
    	@RequestMapping("/testMethod")
    	@ResponseBody
    	public JSON testMethod() { 
    		System.out.println("12345");
    		Map res = new HashMap();
    		res.put("data", 321);
    		return JSONObject.fromObject(res);
    	}
    	
    }

或者

@RestController
    @EnableAutoConfiguration
    @RequestMapping("/test")
    public class TestController { 
    	
    	@RequestMapping("/testMethod")
    	public JSON testMethod() { 
    		System.out.println("12345");
    		Map res = new HashMap();
    		res.put("data", 321);
    		return JSONObject.fromObject(res);
    	}
    	
    }