Spring Boot : Whitelabel Error Page解决方案

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楼主最近爱上了一个新框架——Spring Boot, 搭建快还不用写一堆xml，最重要的是自带Tomcat 真是好

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>com.demo</groupId>
<artifactId>Demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging> <name>Demo</name>
<description>Demo project for Spring Boot</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath /> 
</parent> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties> <dependencies> <dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
<exclusions>
<exclusion>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
</exclusion>
</exclusions>
</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>

controller.java

package com.demo.controller; 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.ResponseBody; import com.demo.domain.User;
import com.demo.service.UserService; @Controller
@RequestMapping(value = "/uc")
public class UserController { @Autowired
private UserService userService; @ResponseBody
@RequestMapping("/stemp.htm")
private String sYeMian(User user){
System.out.println("进了方法 syso"); User u = new User();
u.setMuBan(user.getMuBan()); int i = userService.sYeMian(u); if (i>0){
return "存储成功";
}
return "存储失败";
}
}

DemoApplication.java

package com.demo.example.demo; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication
public class Demo1Application { public static void main(String[] args) {
SpringApplication.run(Demo1Application.class, args);
}
}

然而运行之后就懵逼了

这是咋了，咋的就404了我路径也挺对的啊注解也都写上了啊咋就找不到了呢？ debug吧它不进方法看日志吧，他还不报错这家伙给我急的百度一下午也没解决，最后还是看官网才知道错在了那里，程序只加载Application.java所在包及其子包下的内容。

解决方案：

一、在Application类中加上@ComponentScan(basePackages = {"com.demo.controller"}) 多个之间用","分隔当然，这样治标不治本

package com.demo.example.demo; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan; @SpringBootApplication
@ComponentScan(basePackages = {"com.demo.controller"})
public class Demo1Application { public static void main(String[] args) {
SpringApplication.run(Demo1Application.class, args);
}
}

二、把包的目录结构修改成正确的

package com.demo; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan; @SpringBootApplication
public class Demo1Application { public static void main(String[] args) {
SpringApplication.run(Demo1Application.class, args);
}
}