Java Spring启动银行项目：未显示登录页面

我正在创建一个登录页面，允许用户登录。然而，当我试图通过谷歌浏览器访问时，我看到的只是“索引”，其他什么都没有。但它应该显示我使用HTML和引导创建的登录页面

以下是HomeController.java的代码

package com.userFront.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class HomeController {

    @RequestMapping("/")
    public String home() {
        return "redirect:/index";
    }

    @RequestMapping("/index")
    public @ResponseBody String index() {
        return "index";
    }

}

您可以在此处找到所有项目文件：

更新：1 有人建议我从方法索引（）中删除@ResponseBody。但当我这样做时，会出现以下问题：

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Mon Dec 11 17:52:53 
There was an unexpected error (type=Internal Server Error, status=500).
Circular view path [index]: would dispatch back to the current handler URL [/index] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.) 

更新2: 以下是HomeController类的最新版本，我根据@vtx提供的建议对其进行了修改：

package com.userFront.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

    @Controller
    public class HomeController {

        @RequestMapping("/")
        public String home() {
            return "redirect:/index";
        }

        @RequestMapping("/welcome")
        public String index() {
            return "index";
        }

    }

但现在，出现了一个新的错误，即：

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Mon Dec 11 18:52:41 
There was an unexpected error (type=Not Found, status=404).
No message available

更新3:根据@vtx的建议，我已尝试清理安装Maven。但是，出现以下错误：

[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building UserFront 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ userFront ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 30 resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ userFront ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 9 source files to C:\Users\Kanon\eclipse-workspace\UserFront\target\classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.606 s
[INFO] Finished at: 2017-12-11T23:31:14+06:00
[INFO] Final Memory: 18M/227M
[INFO] ------------------------------------------------------------------------
[WARNING] The requested profile "pom.xml" could not be activated because it does not exist.
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project userFront: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

更新4:根据@vtx的建议，我已经完成了Maven的干净安装。
我关注了stackoverflow.com/questions/19655184/…和stackoverflow.com/questions/19655184/…。Maven安装干净，没有任何错误。但现在，我得到了“圆形视图路径”错误

更新5:@vtx建议我再次使用以下代码：

package com.userFront.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

    @Controller
    public class HomeController {

        @RequestMapping("/")
        public String home() {
            return "redirect:/index";
        }

        @RequestMapping("/welcome")
        public String index() {
            return "index";
        }

    } 

但再一次，我得到了以下错误：

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Tue Dec 12 00:27:42 
There was an unexpected error (type=Not Found, status=404).
No message available

---

这令人难以置信地沮丧。但我不会放弃

注释

@ResponseBody

告诉控制器返回的对象自动序列化为

JSON

并传递回

HttpResponse

对象

您应该删除

@ResponseBody

@RequestMapping("/index")
    public String index() {
        return "index";
    }

我能够通过上面提到的更改成功运行您的代码，我没有遇到任何循环路径错误或404

证明

@Controller
public class HomeController {

    @RequestMapping("/")
    public String home() {
        return "redirect:/index";
    }

    @RequestMapping("/index")
    public  String index() {
        return "index";
    }

}

017-12-11 21:15:07.835信息4840---[ost-startStop-1]o.s.b.w.servlet.ServletRegistrationBean:将servlet:'dispatcherServlet'映射到[/]
2017-12-11 21:15:07.843信息4840---[ost-startStop-1]o.s.b.w.servlet.FilterRegistrationBean:将筛选器：“characterEncodingFilter”映射到：[/*]
2017-12-11 21:15:07.843信息4840---[ost-startStop-1]o.s.b.w.servlet.FilterRegistrationBean:将筛选器：“hiddenHttpMethodFilter”映射到：[/*]
2017-12-11 21:15:07.844信息4840---[ost-startStop-1]o.s.b.w.servlet.FilterRegistrationBean:将筛选器：“httpPutFormContentFilter”映射到：[/*]
2017-12-11 21:15:07.844信息4840---[ost-startStop-1]o.s.b.w.servlet.FilterRegistrationBean:将筛选器：“requestContextFilter”映射到：[/*]
2017-12-11 21:15:08.311信息4840---[main]s.w.s.m.a.RequestMappingHandlerAdapter:正在寻找@ControllerAdvice:org.springframework.boot.context.embedded。AnnotationConfigEmbeddedWebApplicationContext@6c9f5c0d：启动日期[2017年12月11日星期一21:15:04 IST]；上下文层次结构的根
2017-12-11 21:15:08.409信息4840---[main]s.w.s.m.m.a.RequestMappingHandlerMapping:将“{[/index]}”映射到公共java.lang.String.com.userFront.controller.HomeController.index（）上
2017-12-11 21:15:08.410信息4840---[main]s.w.s.m.m.a.RequestMappingHandlerMapping:将“{[/]}”映射到公共java.lang.String.com.userFront.controller.HomeController.home（）
2017-12-11 21:15:08.416 INFO 4840-[main]s.w.s.m.m.a.RequestMappingHandlerMapping:将“{[/error]}”映射到public org.springframework.http.ResponseEntity org.springframework.boot.autoconfigure.web.BasicErrorController.error（javax.servlet.http.HttpServletRequest）
2017-12-11 21:15:08.416 INFO 4840-[main]s.w.s.m.a.RequestMappingHandlerMapping:将“{[/error]，products=[text/html]}”映射到public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml（javax.servlet.http.HttpServletRequest，javax.servlet.http.HttpServletResponse）
2017-12-11 21:15:08.464信息4840---[main]o.s.w.s.handler.simplerlhandler映射：将URL路径[/webjars/**]映射到[class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]类型的处理程序上
2017-12-11 21:15:08.464信息4840---[main]o.s.w.s.handler.simplerlhandlermapping:将URL路径[/**]映射到[class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]类型的处理程序上
2017-12-11 21:15:08.516信息4840---[main]o.s.w.s.handler.simplerlhandler映射：将URL路径[/**/favicon.ico]映射到[class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]类型的处理程序上

---

请执行mvn清洁安装。希望这会有所帮助

我查看了您最近的更改，发现您重定向到了索引，但您没有“/index”的映射。 也许你应该这样做

 @RequestMapping("/")
    public String home() {
        return "redirect:/welcome";
    }

    @RequestMapping("/welcome")
    public String index() {
        return "index";
    }

它会起作用，但似乎不符合逻辑。 只要写

@RequestMapping("/")
    public String home() {
        return "index";
    }

这就是返回索引页的全部内容。

---

如果没有更改默认配置，请确保已将index.html页面设置为src/main/resources/static文件夹，spring boot将在那里查看

使用

“redirect:/index.html”

而不是

“redirect:/index”

学习一个好的spring boot Web初学者教程。您需要将视图定义存储在正确的位置，例如Thymeleaf文件或Freemarker模板。如果没有“index.ftl”或类似内容（在正确的位置），Spring Boot不知道显示什么作为“index”，只需再次调用控制器。另外，您应该显示SecurityConfiguration类，您必须使用它来注册表单登录页。@Florian Albrecht:spring boot starter thymeleaf依赖项在pom中可用，index.html在资源模板位置中可用。因此，如果我们只返回index.html，viewresolver就能够找到index.html文件index@YCF_L还是不行。显示相同的内容。您没有/索引的映射。将

@RequestMapping（“/welcome”）

更改为

@RequestMapping（“/index”）

@john…尝试localhost:8080/welcome或localhost:8080/u

@RequestMapping("/")
    public String home() {
        return "index";
    }