老师，这课后面怎么有其他别的声音？就是背景的声音

JdbcTest.java类

  package com.bjsxt;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JdbcTest {

	//向Dpeartment表中添加一条数据
	public void insertDepartments(String department_name,int location_id) {
			Connection conn= null;
			Statement state= null;
		try {
			/**驱动注册
			Class.forName("com.mysql.jdbc.Driver");
			//创建链接
			conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8", "root", "123456");
			*/
			conn=JdbcUtil.getConnection();
			String sql="insert into departments values(default,'"+department_name+"'"+location_id+")" ;
			state = conn.createStatement();
			int flag =state.executeUpdate(sql);
			System.out.println(flag);
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			//JdbcUtil.closeStatement(state);
			//JdbcUtil.closeConnection(conn);
			JdbcUtil.closeResource(state, conn,null);
		}
		
	}
	//更新departments表中department_id为6的数据，将部门名称修改为教学部，location_id为6
	public void updateDepartments(String department_name,int location_id,int department_id) {
		Connection conn =null;
		Statement state=null;
		try {
			
			conn=JdbcUtil.getConnection();
			state=conn.createStatement();
			String sql="update departments d set d.department_name = '"+department_name+"',d.location_id = "+location_id+" where d.department_id ="+department_id;
			int flag= state.executeUpdate(sql);
			System.out.println(flag);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}finally {  
			JdbcUtil.closeResource(state, conn,null);
		}
	}
	//查询departments表中部门ID为6的部门信息
	public void selectDepartmentsById(int departmentId) {
		Connection conn=null;
		Statement state=null;
		ResultSet rs=null;
		try {
			conn=JdbcUtil.getConnection();
			state= conn.createStatement();
			String sql="select * from departments d where d.department_id = "+departmentId;
			//执行返回结果
			rs= state.executeQuery(sql);
			while(rs.next()) {
				System.out.println(rs.getInt("department_id")+" "+rs.getInt("department_name")+" "+rs.getInt(3));
			}

		}catch(Exception e) {
			e.printStackTrace();
		}finally {
			JdbcUtil.closeResource(state, conn,rs);
		}
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		JdbcTest test=new JdbcTest();
		//test.insertDepartments("研发部", 1);
		//test.updateDepartments("xx部", 8,4 );
		//test.updateDepartments("啰嗦不", 6, 4);
		//test.insertDepartments("干啥不", 10);
		test.selectDepartmentsById(6);
	}

}

JdbcUtil.java类

package com.bjsxt;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;
import java.sql.Statement;

/**
 * Jdbc工具类
 * @author wyz
 *
 */
public class JdbcUtil {
	private static String driver ;
	private static String jdbcurl;
	private static String username;
	private static String password;
	static {
		//读取Properties文件
		ResourceBundle bundle = ResourceBundle.getBundle("jdbc");
		driver=bundle.getString(driver);
		jdbcurl=bundle.getString(jdbcurl);
		username=bundle.getString(username);
		password=bundle.getString(password);
		try {
			Class.forName(driver);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}
	//获取Connection对象
	public static Connection getConnection() {
		Connection conn=null;
		try {
			conn= DriverManager.getConnection(jdbcurl,username,password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}
	//关闭statement
	public static void closeStatement(Statement state) {
			try {
				if(state!=null) {
					state.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}	
	}
	//关闭Connection
	public static void closeConnection(Connection conn) {
		try {
			if(conn!=null) {
			conn.close();
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	//关闭资源
	public static void closeResource(Statement state,Connection conn,ResultSet rs) {
		closeStatement(state);
		closeConnection(conn);
		closeResultSet(rs);
	}
	//关闭ResultSet链接
	public static void closeResultSet(ResultSet rs)  {
		try {
			if(rs!= null) {
			rs.close();
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

jdbc.properties

driver   =com.mysql.jdbc.Driver
jdbcurl  =jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
username =root
password =123456

还是报错跟之前同学们一样的问题，我看不太懂导包啥的我报错就是这样的

这是下面一章了，这章我就一直报错，找了好久没解决问题，学习下面一章的时候还是报错。麻烦老师详细解释一下

ss-hd-text 这个属性也是swiper里的吗？  我在swiper网站里的参数没找到，加了后会有一个定位和背景的效果，麻烦老师指明出处

老师，请问一下面这个是什么意思，没有理解

老师您好，课程里讲：只能排除依赖的jar包，不能排除包含的jar包。

请问啥叫包含的jar，能举个例子说明下吗？

新写的程序，idea总要重新设置新写的程序为启动程序？比较麻烦，怎么设置下

老师我想问

视频说dependenceManager里面配置的依赖在打包的时候都不会注入到依赖中，那dependence依赖打包的时候是注入到这个项目中吗？

刚刚第41课时排除依赖那节中，exclusions 说只能排除依赖，不能排除包含。那我们dependence依赖打包后的项目，项目和依赖属于是包含么？

为什么一个文件中可以有多个类（一个为public类，其余为default类），这样的好处什么呢？

老师这课程没更新全吧?????   12小节网易云音乐完了之后应该还有呢吧??

老师说使用这些方法操作之后不是生成了新的字符串吗？  那为什么 使用方法后输出str7和str8字符串改变了呢？原来的字符串呢？不是不改变吗

老师，您好。系统变量也配了，重启cmd进行登录时 ，还是出现下列问题:

老师您好，在启动LivegoodsGatewayApp时，提示如下错误信息。请问这个应该如何解决呢。谢谢！

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

2020-07-08 02:37:12.389 ERROR 84132 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.context.ApplicationContextException: Unable to start reactive web server; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'nettyReactiveWebServerFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryConfiguration$EmbeddedNetty.class]: Unsatisfied dependency expressed through method 'nettyReactiveWebServerFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'reactorServerResourceFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryConfiguration$EmbeddedNetty.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: io/netty/util/AttributeKey

at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.onRefresh(ReactiveWebServerApplicationContext.java:81) ~[spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66) ~[spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at com.livegoods.gateway.LivegoodsGatewayApplication.main(LivegoodsGatewayApplication.java:13) [classes/:na]

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'nettyReactiveWebServerFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryConfiguration$EmbeddedNetty.class]: Unsatisfied dependency expressed through method 'nettyReactiveWebServerFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'reactorServerResourceFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryConfiguration$EmbeddedNetty.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: io/netty/util/AttributeKey

at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:539) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.getWebServerFactory(ReactiveWebServerApplicationContext.java:111) ~[spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.createWebServer(ReactiveWebServerApplicationContext.java:89) ~[spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.onRefresh(ReactiveWebServerApplicationContext.java:78) ~[spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]

... 8 common frames omitted

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'reactorServerResourceFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryConfiguration$EmbeddedNetty.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: io/netty/util/AttributeKey

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

... 20 common frames omitted

Caused by: java.lang.NoClassDefFoundError: io/netty/util/AttributeKey

at reactor.netty.resources.PooledConnectionProvider.<clinit>(PooledConnectionProvider.java:204) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.resources.ConnectionProvider$Builder.build(ConnectionProvider.java:439) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.resources.ConnectionProvider.fixed(ConnectionProvider.java:331) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.resources.ConnectionProvider.fixed(ConnectionProvider.java:272) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.resources.ConnectionProvider.fixed(ConnectionProvider.java:251) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.tcp.TcpResources.create(TcpResources.java:331) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.tcp.TcpResources.getOrCreate(TcpResources.java:275) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at reactor.netty.http.HttpResources.get(HttpResources.java:42) ~[reactor-netty-0.9.5.RELEASE.jar:0.9.5.RELEASE]

at org.springframework.http.client.reactive.ReactorResourceFactory.afterPropertiesSet(ReactorResourceFactory.java:202) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]

... 31 common frames omitted

Caused by: java.lang.ClassNotFoundException: io.netty.util.AttributeKey

at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_211]

at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_211]

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_211]

at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_211]

... 42 common frames omitted

pom文件中已经添加了mapper依赖，但是启动还是报错

老师，问一下这个查询语句怎么写出来  （实操中的31）

31. 求部门经理人中平均薪水最低的部门名称

如果改用这个方法是可以成功的，但是用to_dict_msg 就会出这个问题，TypeError: 'dict' object is not callable