Spring Boot 控制器 404 [英] Spring Boot Controller 404

问题描述

我是 Spring Boot 的新手，正在尝试构建一个简单的 Web 应用程序.我已经定义了一个包含我的 url 映射的控制器类，但是在浏览器上它给了我一个白标签页面错误 (404).我不明白为什么它不能映射.我已经尝试更改我的组件扫描基础包，但它仍然没有将我重定向到页面abc"或在控制台中打印in controller".

I am fairly new in Spring Boot and trying to build a simple web app. I have defined a controller class containing my mapping for url, but on browser it is giving me a white label page error(404). I am not able to understand why it is not able to map. I have tried changing my component scan base package, but it still doesn't redirect me to page "abc" or print "in controller" in the console.

pom.xml

<?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>bms</groupId>
    <artifactId>com.wellmanage.bms</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>BMS</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>


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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

控制器类

package com.wellmanage.controller;   

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;

@Controller
public class BookController {

    @RequestMapping("/")
    public String hello() {
        System.out.println("in controller");
        return "abc";
    }
}

主类

package com.wellmanage.bms;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class BmsApplication {

    public static void main(String[] args) {
        SpringApplication.run(BmsApplication.class, args);
    }
}

推荐答案

BmsApplication 类放在 com.wellmanage.bms 包下，默认情况下 >@SpringBootApplication 注释使用这个包作为根运行组件扫描.由于 BookController 位于 com.wellmanage.controller 内，因此默认配置省略了该包.

The BmsApplication class is placed under the com.wellmanage.bms package and by default the @SpringBootApplication annotation runs component scan using this package as the root. Since the BookController is inside com.wellmanage.controller, the package is omitted by default configuration.

您有两个选择:

1. 更改默认组件扫描设置并设置您要扫描的包:

    @ComponentScan("com.wellmanage")
    @SpringBootApplication
    public class BmsApplication {

        public static void main(String[] args) {
            SpringApplication.run(BmsApplication.class, args);
        }
    }

1. 将主应用程序类移动到您的应用程序的根包，以便您要自动扫描的所有组件都在其包下，例如com.wellmanage.

从您发布的配置来看，您似乎没有设置任何模板引擎.因此忽略从控制器返回字符串abc".

From the configuration you have posted, it seems you didn't set any template engine. Returning the String "abc" from your controller is hence ignored.

这篇关于Spring Boot 控制器 404的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！