springboot整合mybatis 小练习

矫情吗；* 2022-04-23 08:10 92阅读 0赞

最近在学习springboot.

Spring Boot是由Pivotal团队提供的全新框架，其设计目的是用来简化新Spring应用的初始搭建以及开发过程。该框架使用了特定的方式来进行配置，从而使开发人员不再需要定义样板化的配置。通过这种方式，Spring Boot致力于在蓬勃发展的快速应用开发领域(rapid application development)成为领导者。

--------------以上来自百度百科

总之，springboot 还是值得好好学习的，毕竟它比spring 少了 很麻烦的配置以及依赖，尤其是pom文件中引入maven依赖的时候很简洁。

下面我来搭建一个简单的springbooot+mybatis 项目，期间也遇到了一些问题，做一下记录和整理：

一。环境

1.开发工具： idea 2018.1.5

2.springboot版本： 2.0.8.RELEASE

二。开始创建一个工程

1.new --> Project

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70][]

选择 Spring Initializr 下一步

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 1][]

填写相应的工程名及包名，下一步

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 2][]

选择需要用到的组件，因为是 我这里选择了 web,mysql和mybatis 下一步

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 3][]

选择finish

![2019012915470037.png][]

使用新窗口打开

二。后续工作

1.先修改maven的设置，下载maven jar包

这一步我就不贴图了。

2.下面我们来看一下pom文件

<?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>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.8.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.taoj</groupId>
        <artifactId>springboot_mybatis07</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>springboot_mybatis07</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>2.0.0</version>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </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>

其中引入了web的起步依赖，mybatis和mysql的起步依赖，还有测试test的起步依赖。

接下来我们来看一下项目的结构：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 4][]

其中有一个启动类 SpringbootMybatis07Application 通常我们可以直接启动一下我们这个启动类，我们来启动一下，  
![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 5][]

在启动过程中 控制台输出这个图标：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 6][]

表示是springboot的项目，但是后面报错了。

"C:\Program Files (x86)\Java\jdk1.8.0_171\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=61815 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:H:\java_2018\idea\JetBrains\IntelliJ IDEA 2018.1.5\lib\idea_rt.jar=61816:H:\java_2018\idea\JetBrains\IntelliJ IDEA 2018.1.5\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\charsets.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\deploy.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\access-bridge-64.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\cldrdata.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\dnsns.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\jaccess.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\jfxrt.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\localedata.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\nashorn.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\sunec.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\sunjce_provider.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\sunmscapi.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\sunpkcs11.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\ext\zipfs.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\javaws.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\jce.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\jfr.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\jfxswt.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\jsse.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\management-agent.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\plugin.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\resources.jar;C:\Program Files (x86)\Java\jdk1.8.0_171\jre\lib\rt.jar;I:\TYWorkspace\study\Resource\02springboot_test02\springboot_mybatis07\target\classes;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter-web\2.0.8.RELEASE\spring-boot-starter-web-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter\2.0.8.RELEASE\spring-boot-starter-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot\2.0.8.RELEASE\spring-boot-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-autoconfigure\2.0.8.RELEASE\spring-boot-autoconfigure-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter-logging\2.0.8.RELEASE\spring-boot-starter-logging-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;H:\apache_maven\local_repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;H:\apache_maven\local_repository\org\apache\logging\log4j\log4j-to-slf4j\2.10.0\log4j-to-slf4j-2.10.0.jar;H:\apache_maven\local_repository\org\apache\logging\log4j\log4j-api\2.10.0\log4j-api-2.10.0.jar;H:\apache_maven\local_repository\org\slf4j\jul-to-slf4j\1.7.25\jul-to-slf4j-1.7.25.jar;H:\apache_maven\local_repository\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;H:\apache_maven\local_repository\org\yaml\snakeyaml\1.19\snakeyaml-1.19.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter-json\2.0.8.RELEASE\spring-boot-starter-json-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\core\jackson-databind\2.9.8\jackson-databind-2.9.8.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\core\jackson-core\2.9.8\jackson-core-2.9.8.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.8\jackson-datatype-jdk8-2.9.8.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.8\jackson-datatype-jsr310-2.9.8.jar;H:\apache_maven\local_repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.8\jackson-module-parameter-names-2.9.8.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter-tomcat\2.0.8.RELEASE\spring-boot-starter-tomcat-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\org\apache\tomcat\embed\tomcat-embed-core\8.5.37\tomcat-embed-core-8.5.37.jar;H:\apache_maven\local_repository\org\apache\tomcat\embed\tomcat-embed-el\8.5.37\tomcat-embed-el-8.5.37.jar;H:\apache_maven\local_repository\org\apache\tomcat\embed\tomcat-embed-websocket\8.5.37\tomcat-embed-websocket-8.5.37.jar;H:\apache_maven\local_repository\org\hibernate\validator\hibernate-validator\6.0.14.Final\hibernate-validator-6.0.14.Final.jar;H:\apache_maven\local_repository\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;H:\apache_maven\local_repository\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;H:\apache_maven\local_repository\com\fasterxml\classmate\1.3.4\classmate-1.3.4.jar;H:\apache_maven\local_repository\org\springframework\spring-web\5.0.12.RELEASE\spring-web-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-beans\5.0.12.RELEASE\spring-beans-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-webmvc\5.0.12.RELEASE\spring-webmvc-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-aop\5.0.12.RELEASE\spring-aop-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-context\5.0.12.RELEASE\spring-context-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-expression\5.0.12.RELEASE\spring-expression-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.0.0\mybatis-spring-boot-starter-2.0.0.jar;H:\apache_maven\local_repository\org\springframework\boot\spring-boot-starter-jdbc\2.0.8.RELEASE\spring-boot-starter-jdbc-2.0.8.RELEASE.jar;H:\apache_maven\local_repository\com\zaxxer\HikariCP\2.7.9\HikariCP-2.7.9.jar;H:\apache_maven\local_repository\org\springframework\spring-jdbc\5.0.12.RELEASE\spring-jdbc-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-tx\5.0.12.RELEASE\spring-tx-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.0.0\mybatis-spring-boot-autoconfigure-2.0.0.jar;H:\apache_maven\local_repository\org\mybatis\mybatis\3.5.0\mybatis-3.5.0.jar;H:\apache_maven\local_repository\org\mybatis\mybatis-spring\2.0.0\mybatis-spring-2.0.0.jar;H:\apache_maven\local_repository\mysql\mysql-connector-java\5.1.47\mysql-connector-java-5.1.47.jar;H:\apache_maven\local_repository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar;H:\apache_maven\local_repository\org\springframework\spring-core\5.0.12.RELEASE\spring-core-5.0.12.RELEASE.jar;H:\apache_maven\local_repository\org\springframework\spring-jcl\5.0.12.RELEASE\spring-jcl-5.0.12.RELEASE.jar" com.taoj.SpringbootMybatis07Application
    
      .   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::        (v2.0.8.RELEASE)
    
    2019-01-29 16:06:20.594  INFO 9220 --- [           main] com.taoj.SpringbootMybatis07Application  : Starting SpringbootMybatis07Application on DESKTOP-VUUV0KL with PID 9220 (I:\TYWorkspace\study\Resource\02springboot_test02\springboot_mybatis07\target\classes started by 蒋涛 in I:\TYWorkspace\study\Resource\02springboot_test02\springboot_mybatis07)
    2019-01-29 16:06:20.605  INFO 9220 --- [           main] com.taoj.SpringbootMybatis07Application  : No active profile set, falling back to default profiles: default
    2019-01-29 16:06:20.772  INFO 9220 --- [           main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4387b79e: startup date [Tue Jan 29 16:06:20 CST 2019]; root of context hierarchy
    2019-01-29 16:06:21.769  WARN 9220 --- [           main] o.m.s.mapper.ClassPathMapperScanner      : No MyBatis mapper was found in '[com.taoj]' package. Please check your configuration.
    2019-01-29 16:06:22.983  INFO 9220 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    2019-01-29 16:06:23.020  INFO 9220 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    2019-01-29 16:06:23.020  INFO 9220 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.37
    2019-01-29 16:06:23.025  INFO 9220 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener   : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:\Program Files (x86)\Java\jdk1.8.0_171\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\Program Files (x86)\Common Files\NetSarang;C:\ProgramData\Oracle\Java\javapath;H:\DBServer\oracle\OracleClient\oracle\product\10.2.0\client_1\bin;H:\DBServer\oracle\oracle11\app\蒋涛\product\11.2.0\dbhome_1\bin;C;\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Java\jdk1.7.0_67\bin;H:\android-sdk-windows\build-tools\22.0.1;H:\android-sdk-windows\tools;H:\android-sdk-windows\platform-tools;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;H:\SVN\bin;H:\apache_maven\apache-maven-3.5.3\bin;G:\software\git\cmd;G:\software\TortoiseGit\bin;C:\Program Files (x86)\Common Files\Apple\Internet Services\;C:\Users\蒋涛\AppData\Local\GitHubDesktop\bin;%USERPROFILE%\AppData\Local\Microsoft\WindowsApps;;.]
    2019-01-29 16:06:23.206  INFO 9220 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2019-01-29 16:06:23.207  INFO 9220 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2447 ms
    2019-01-29 16:06:23.313  INFO 9220 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Servlet dispatcherServlet mapped to [/]
    2019-01-29 16:06:23.319  INFO 9220 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
    2019-01-29 16:06:23.319  INFO 9220 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
    2019-01-29 16:06:23.320  INFO 9220 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
    2019-01-29 16:06:23.320  INFO 9220 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
    2019-01-29 16:06:23.570  INFO 9220 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
    2019-01-29 16:06:23.914  INFO 9220 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@4387b79e: startup date [Tue Jan 29 16:06:20 CST 2019]; root of context hierarchy
    2019-01-29 16:06:24.018  INFO 9220 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
    2019-01-29 16:06:24.020  INFO 9220 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
    2019-01-29 16:06:24.058  INFO 9220 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
    2019-01-29 16:06:24.058  INFO 9220 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
    2019-01-29 16:06:24.147  WARN 9220 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
    2019-01-29 16:06:24.151  INFO 9220 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
    2019-01-29 16:06:24.179  INFO 9220 --- [           main] ConditionEvaluationReportLoggingListener : 
    
    Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
    2019-01-29 16:06:24.187 ERROR 9220 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 
    
    ***************************
    APPLICATION FAILED TO START
    ***************************
    
    Description:
    
    Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.
    
    Reason: Failed to determine a suitable driver class
    
    
    Action:
    
    Consider the following:
    	If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    	If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).
    
    
    Process finished with exit code 1

报错原因为：因为我们引入了mybatis 需要配置一下数据库的一些信息

如果我们没有引入mybatis的组件，我们就可以直接启动，并且可以编写controller, 现在要需要添加数据库的配置信息，我们在resources下面新建一个application.yml文件。我们看到已经有一个application.properties文件了，为什么不用这个文件进行配置呢，原因可以自行查询。既然使用了springboot ，咱们就学点新的东西，application.yml文件配置更加的简洁。

接下来贴出application.yml 中的内容：

# 配置数据源
    spring:
      datasource:
        url: jdbc:mysql://localhost:3306/test
        driver-class-name: com.mysql.jdbc.Driver
        data-username: root
        data-password: 11111111

接下来我们再启动项目

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 7][]

默认启动为8080端口。接下来我们来访问一下项目：

在浏览器输入： [http://127.0.0.1:8080/][http_127.0.0.1_8080]

结构如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 8][]

因为springboot内部默认配置了一个tomcat ,所以我们可以直接访问，以前的tomat访问是一只猫的页面，现在不是了，如上图所示也是正确的。

三。编写controller

接下来我们来编写一个Controller类，写一个helloworld

package com.taoj.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    @Controller
    public class HelloController {
    
        @RequestMapping("/hello")
        @ResponseBody
        public String sayHello(){
            return "hello world";
        }
    
    }

在类上我们添加 @Controller 注解 方法上添加 @RequestMapping() 和 @ResponseBody 注解

接下来我们重启一下项目。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 9][]

启动没有报错，重新访问一下tomcat ： [http://127.0.0.1:8080/][http_127.0.0.1_8080] 结果正常

接下来 访问[http://127.0.0.1:8080/hello][http_127.0.0.1_8080_hello]

页面为：

![20190129162435527.png][]

这就是一个最简单的springboot web项目

四。修改配置，

1.接下来我们来说一下，如何修改默认的tomcat端口，以及项目跟目录名

在配置文件 application.yml 文件中如下配置：

# 配置tomcat
    server:
      servlet:
        context-path: /mybatis
      port: 8085

完整的application.yml 如下：

# 配置数据源
    spring:
      datasource:
        url: jdbc:mysql://localhost:3306/test
        driver-class-name: com.mysql.jdbc.Driver
        data-username: root
        data-password: 11111111
    
    # 配置tomcat
    server:
      servlet:
        context-path: /mybatis
      port: 8085

重启项目后没有报错，继续访问：

[http://127.0.0.1:8085/mybatis/hello][http_127.0.0.1_8085_mybatis_hello]

![20190129162851975.png][]

如上有没有发现，端口号和项目名已经变了

五。接下来我们说正事，要整合mybatis

先说一下，现在用的mybatis是配置文件的方式：

1.先新建一个数据库表

CREATE TABLE student(
      id INT PRIMARY KEY AUTO_INCREMENT,
      NAME VARCHAR(20),
      address VARCHAR(30)
    );
    
    SELECT * FROM student;
    
    INSERT INTO student() VALUES (1001, '测试', '北京');

新建一个表，并插入一条语句

2.新建一个实体类Student

package com.taoj.entity;
    
    public class Student {
    
        private int id;
        private String name;
        private String address;
    
        public int getId() {
            return id;
        }
    
        public void setId(int id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getAddress() {
            return address;
        }
    
        public void setAddress(String address) {
            this.address = address;
        }
    
        @Override
        public String toString() {
            return "Student{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", address='" + address + '\'' +
                    '}';
        }
    }

3.添加一个Dao接口

package com.taoj.dao;
    
    import com.taoj.entity.Student;
    
    public interface StudentDao {
    
        Student findOneStu(int id);
    
    }

其中就只有一个方法 findOneStu(int id)

4.接下来添加一个Mapper文件

在resources文件夹下新建一个mapper文件夹，再创建一个StudentMapper.xml

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 10][]

代码如下：

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    <mapper namespace="com.taoj.dao.StudentDao">
        <select id="findOneStu" parameterType="int" resultType="com.taoj.entity.Student">
            SELECT * FROM student WHERE id=#{id}
        </select>
    </mapper>

5.添加一个StudentService

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70 11][]

代码如下：

package com.taoj.service;
    
    import com.taoj.dao.StudentDao;
    import com.taoj.entity.Student;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    @Service
    public class StudentService {
    
        @Autowired
        private StudentDao dao;
    
        public Student findOneStu(int id){
            return dao.findOneStu(id);
        }
    
    }

6.然后在application.yml文件中添加mybatis的映射文件路径：

# 指定mybatis映射文件地址：
    mybatis:
      mapper-locations: classpath:mapper/*.xml

application.yml完整文件如下：

7.接下来在Controller添加一个方法，

HelloController中完整代码如下：

package com.taoj.controller;
    
    import com.taoj.entity.Student;
    import com.taoj.service.StudentService;
    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;
    
    @Controller
    public class HelloController {
    
        @Autowired
        private StudentService service;
    
        @RequestMapping("/hello")
        @ResponseBody
        public String sayHello(){
            return "hello world";
        }
    
        @RequestMapping("/find")
        @ResponseBody
        public String find(){
            Student stu = new Student();
            stu = service.findOneStu(1001);
            return stu.toString();
        }
    
    }

8.接下来这一步非常重要：在启动类上添加对dao层的扫描，也就是在启动类上添加一个注解：

@MapperScan("com.taoj.dao")

启动类完整如下：

package com.taoj;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    @MapperScan("com.taoj.dao")
    public class SpringbootMybatis07Application {
    
        public static void main(String[] args) {
            SpringApplication.run(SpringbootMybatis07Application.class, args);
        }
    
    }

9.然后再启动项目，发现有个报错：

java.sql.SQLException: Access denied for user ''@'localhost' (using password: NO)
    	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3978) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3914) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:4429) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1276) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2199) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2230) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2025) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:778) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_171]
    	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_171]
    	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_171]
    	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_171]
    	at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:117) ~[HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:365) ~[HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:194) ~[HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:460) [HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:534) [HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) [HikariCP-2.7.9.jar:na]
    	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-2.7.9.jar:na]
    	at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157) [spring-jdbc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82) [mybatis-spring-2.0.0.jar:2.0.0]
    	at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68) [mybatis-spring-2.0.0.jar:2.0.0]
    	at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:336) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:85) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77) [mybatis-3.5.0.jar:3.5.0]
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
    	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
    	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) [mybatis-spring-2.0.0.jar:2.0.0]
    	at com.sun.proxy.$Proxy57.selectOne(Unknown Source) [na:na]
    	at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166) [mybatis-spring-2.0.0.jar:2.0.0]
    	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:84) [mybatis-3.5.0.jar:3.5.0]
    	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:58) [mybatis-3.5.0.jar:3.5.0]
    	at com.sun.proxy.$Proxy58.findOneStu(Unknown Source) [na:na]
    	at com.taoj.service.StudentService.findOneStu(StudentService.java:15) [classes/:na]
    	at com.taoj.controller.HelloController.find(HelloController.java:26) [classes/:na]
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
    	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
    	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:891) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:981) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:873) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:858) [spring-webmvc-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.12.RELEASE.jar:5.0.12.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_171]
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_171]
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.37.jar:8.5.37]
    	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_171]

其中： java.sql.SQLException: Access denied for user ''@'localhost' (using password: NO) 说明数据库连接不上，我们来看一看配置文件

把

data-username: root
    data-password: 11111111

改为：

username: root
    password: 11111111

然后再重新启动，报错消息，我们来访问一下：

[http://127.0.0.1:8085/mybatis/hello][http_127.0.0.1_8085_mybatis_hello]

![20190129165618654.png][]

正常

访问： [http://127.0.0.1:8085/mybatis/find][http_127.0.0.1_8085_mybatis_find]

![20190129165656423.png][]

正常 ，搞定！！

以上为我学习springboot整合mybatis时记录的学习文章，供以后自己查看，也欢迎别人查看，我也是在前人的博客基础上自学的，现在感谢一下这些前辈：

[https://blog.csdn.net/litianxiang\_kaola/article/details/79481422][https_blog.csdn.net_litianxiang_kaola_article_details_79481422]

[https://blog.csdn.net/saytime/article/details/74783296][https_blog.csdn.net_saytime_article_details_74783296]

[https://blog.csdn.net/qq\_35153200/article/details/79538434][https_blog.csdn.net_qq_35153200_article_details_79538434]

不积跬步，无以至千里

不积小流，无以成江海

这里说一个插曲，我当时在调试这个demo的时候，总是有一个报错，NullPointException ，因为使用了mybatis后查询不到对象，toString()方法时报错了，我一直找不到原因，后来就重新来了一遍，居然成了。

最后附上完整代码地址：

[https://github.com/taoxiaotao6/springboot\_mybatis.git][https_github.com_taoxiaotao6_springboot_mybatis.git]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdXlpbmcxODAyMDI4OTE1_size_16_color_FFFFFF_t_70]: /images/20220322/9d02f44b6324472c86952b066562645c.png
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[http_127.0.0.1_8080]: http://127.0.0.1:8080/
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[http_127.0.0.1_8080_hello]: http://127.0.0.1:8080/hello
[20190129162435527.png]: /images/20220322/f43a1e2d972e4e80ba67da1d2538f06a.png
[http_127.0.0.1_8085_mybatis_hello]: http://127.0.0.1:8085/mybatis/hello
[20190129162851975.png]: /images/20220322/58c4aa13e333456da2ade0d5c866890f.png
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[20190129165618654.png]: /images/20220322/cf2871cacffc4cbd80fb8e39ce6dfc53.png
[http_127.0.0.1_8085_mybatis_find]: http://127.0.0.1:8085/mybatis/find
[20190129165656423.png]: /images/20220322/2e103fd2b4f74bd195ab6a2bbf48c47c.png
[https_blog.csdn.net_litianxiang_kaola_article_details_79481422]: https://blog.csdn.net/litianxiang_kaola/article/details/79481422
[https_blog.csdn.net_saytime_article_details_74783296]: https://blog.csdn.net/saytime/article/details/74783296
[https_blog.csdn.net_qq_35153200_article_details_79538434]: https://blog.csdn.net/qq_35153200/article/details/79538434
[https_github.com_taoxiaotao6_springboot_mybatis.git]: https://github.com/taoxiaotao6/springboot_mybatis.git