SpringBoot入门Demo,一次深夜踩坑记录。
springboot小项目开启后，访问端口无反应。
首先看我的项目目录：
项目的pom文件内容如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 <?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.bes</groupId> <artifactId>spring-colud</artifactId> <version>1.0.0-SNAPSHOT</version> <modules> <module>user-service</module> </modules> <packaging>pom</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.4.RELEASE</version> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-cloud.version>Finchley.SR1</spring-cloud.version> <mapper.starter.version>2.0.3</mapper.starter.version> <mysql.version>5.1.32</mysql.version> <pageHelper.starter.version>1.2.5</pageHelper.starter.version> </properties> <dependencyManagement> <dependencies> <!-- springcloud --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> </dependency> <!-- 通用Mapper启动器 --> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>${mapper.starter.version}</version> </dependency> <!-- 分页助手启动器 --> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version>${pageHelper.starter.version}</version> </dependency> <!-- mysql驱动 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.4</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> 我的application.yml配置为：
server: port: 8081 spring: datasource: url: jdbc:mysql://localhost:3306/springboot username: root password: root mybatis: type-aliases-package: com.bes.user.domain
UserDao为
1 2 3 4 5 6 7 8 package com.bes.user.dao; import com.bes.user.domain.User; import org.springframework.stereotype.Repository; import tk.mybatis.mapper.common.Mapper; public interface UserDao extends Mapper<User> { } UserService为：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 package com.bes.user.service; import com.bes.user.dao.UserDao; import com.bes.user.domain.User; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; @Service @Transactional public class UserService { @Autowired UserDao userDao; public User findById(Integer id) { User user = userDao.selectByPrimaryKey(id); return user; } } UserController为：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 package com.bes.user.web; import com.bes.user.domain.User; import com.bes.user.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/user") public class UserController { @Autowired UserService userService; @GetMapping("{id}") public User findById(@PathVariable("id")Integer id) { User user = userService.findById(id); return user; } } UserApplication为：
1 2 3 4 5 6 7 8 9 10 11 12 13 package com.bes; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import tk.mybatis.spring.annotation.MapperScan; @SpringBootApplication @MapperScan("com.bes.user.dao") public class UserApplication { public static void main(String[] args) { SpringApplication.run(UserApplication.class, args); } } 上述代码是填坑之后的，而错误的原因也非常奇葩在UserService中自动注入UserDao时提示我没有UserDao这个bean.
于是我就在UserDao上加了一个@Repository注解，如下图：
而后UserService不在报错了，运行UserApplication项目正常起来了。
但是通过浏览器访问时却一片空白。
这时在回到IDEA查看下方日志多了两行东西。1111是我调试时让它打印的无关东西。
这个奇怪的错误搞了我几个小时。最后发现不因给在UserDao上加@Reposity注解。UserService中注入Use人Dao报错时应如下处理：
1、鼠标点击报错的UserService中报错的UserDao
2、ALT+ENTER
3、选择第一个选项
4、在选择disable开头的选项
问题解决。
以上这篇SpringBoot服务开启后通过端口访问无反应的解决就是小编分享给大家的全部内容了
