一、搭建spring boot环境
maven工程
pom文件内容
<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.qm.demo</groupId> <artifactId>springbootDemo</artifactId> <version>0.0.1-SNAPSHOT</version>
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.2.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> </dependency> <dependency> <groupId>MySQL</groupId> <artifactId>mysql-connector-Java</artifactId> <version>5.0.8</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.9</version> </dependency> <dependency> <groupId>org.antlr</groupId> <artifactId>antlr4-runtime</artifactId> <version>4.1</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional><!– optional=true,依赖不会传递,该项目依赖devtools;之后依赖myboot项目的项目如果想要使用devtools,需要重新引入 –> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <scope>provided</scope> </dependency> </dependencies> <!– <build> <plugins> java编译插件 <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.2</version> <configuration> <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <configuration> <port>8080</port> <path>/</path> <url>http://192.168.25.135:8080/manager/text</url> 用户名 <username>tomcat</username> 密码 <password>tomcat</password> </configuration> </plugin> </plugins> </build> –> </project>
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项目目录结构
其中springTest类是spring boot内部tomcat启动时要运行的类
其中内容如下
package com.qm;
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.web.servlet.ServletComponentScan; import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import com.qm.controller.UserController;
@SpringBootApplication public class SpringTest { public static void main(String[] args) { SpringApplication.run(SpringTest.class, args); } } |
Application类的作用是外部服务器启动spring boot所要做的一些事。内容如下
package com.qm;
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.builder.SpringApplicationBuilder; import org.springframework.boot.web.support.SpringBootServletInitializer; import org.springframework.context.annotation.ComponentScan;
@SpringBootApplication @ComponentScan public class Application extends SpringBootServletInitializer{ /** * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行 */ @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) { builder.sources(this.getClass()); return super.configure(builder); } public static void main(String[] args) { SpringApplication.run(Application.class, args); } }
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application.properties文件内容如下
server.port=8080 spring.datasource.url=jdbc:mysql://localhost:3309/springbootdemo spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.username=root spring.datasource.password=123456 spring.jpa.show-sql=true spring.jpa.hibernate.ddl-auto=update spring.devtools.livereload.enabled=true
//热部署,需要提供的路径 spring.devtools.restart.additional-paths=src//main//java//com//qm spring.thymeleaf.cache=false
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踩过的坑
坑一,
一开始以为文件目录,可以随便放,经过坑一的教训,才知道代码文件存放有一定的顺序
如上项目结构图,其中springtest类和application类一定要放在最外面的包里,如com.qm 当启动spring boot时,它会去加载com.qm包及其子包下的所有类,
当你不按顺序时,[email protected],会报以下错误
Description:
Field userService in com.qm.controller.UserController required a bean of type ‘com.qm.service.UserService’ that could not be found.
Action:
Consider defining a bean of type ‘com.qm.service.UserService’ in your configuration.
,即bean找不到。,这是应该注意代码顺序。
坑二
补齐坑一后,在service层的接口继承jpa,然后在controller层使用注入的service方法会报以下错误
Error creating bean with name ‘dataController’: Unsatisfied dependency expressed through field ‘personRepository’; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘personRepository’: Invocation of init method failed; nested exception is org.springframework.data.mapping.PropertyReferenceException: No property auto found for type Person!
这是因为hibernate版本的问题,
只要加上
<dependency>
<groupId>org.antlr</groupId>
<artifactId>antlr4-runtime</artifactId>
<version>4.1</version>
这个依赖即可
添加之后,若maven仓库中有该jar包,最好删掉,编译时重新下载
若spring boot正常启动,而地址栏访问不到controller,则此时应该注意,spring boot启动时,未扫描到controller类,
在spring boot入口类上再添加一个注解
@ComponentScan(“要扫描的包名”)
以上就是我在学spring boot时遇到过得一些坑。
原创文章,作者:奋斗,如若转载,请注明出处:https://blog.ytso.com/12350.html