java.sql.SQLException:无法加载类：com.mysql.jdbc.Driver

我希望能够将我的程序连接到数据库。但由于我以前从未使用过数据库，因此我将遵循以下教程：。在完成本教程的所有步骤（据我所知）后，我得到以下堆栈跟踪：

java.sql.SQLException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:sun.misc.Launcher$AppClassLoader@34a245ab;ClassLoader:sun.misc.Launcher$AppClassLoader@34a245ab
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:283) ~[tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:716) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:648) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:468) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.4.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.4.jar:na]
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) [spring-jdbc-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) [spring-jdbc-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.jdbc.datasource.init.DatabasePopulatorUtils.execute(DatabasePopulatorUtils.java:46) [spring-jdbc-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.runScripts(DataSourceInitializer.java:176) [spring-boot-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.runSchemaScripts(DataSourceInitializer.java:85) [spring-boot-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.init(DataSourceInitializer.java:77) [spring-boot-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_92]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_92]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_92]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_92]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:365) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:310) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:133) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:408) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1570) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:220) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:353) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:334) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerPostProcessor.postProcessAfterInitialization(DataSourceInitializerPostProcessor.java:62) [spring-boot-autoconfigure-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:422) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1583) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1214) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:372) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1076) [spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:851) [spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) [spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:369) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at edu.demo.SpringbootJdbcDemoApplication.main(SpringbootJdbcDemoApplication.java:9) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_92]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_92]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_92]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_92]
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) [idea_rt.jar:na]

User.java

package edu.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootJdbcDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringbootJdbcDemoApplication.class, args);
    }
}

    package edu.demo;

    public class User{
        private Integer id;
        private String name;
        private String email;

    public User(int number, String strName, String strEmail){
        id = number;
        name = strName;
        email = strEmail;
    }

    public User(){

    }
    public Integer getId() {
        return id;
    }

    public String getEmail() {
        return email;
    }

    public String getName() {
        return name;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

SpringbootJdbcDemoApplicationTests.java

package edu.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootJdbcDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringbootJdbcDemoApplication.class, args);
    }
}

    package edu.demo;

    public class User{
        private Integer id;
        private String name;
        private String email;

    public User(int number, String strName, String strEmail){
        id = number;
        name = strName;
        email = strEmail;
    }

    public User(){

    }
    public Integer getId() {
        return id;
    }

    public String getEmail() {
        return email;
    }

    public String getName() {
        return name;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

包edu.demo；
导入org.springframework.beans.factory.annotation.Autowired；
导入org.springframework.boot.test.SpringApplicationConfiguration；
导入org.springframework.boot.test.context.SpringBootTest；
导入org.springframework.test.context.junit4.SpringJUnit4ClassRunner；
导入java.util.List；
导入org.junit.*；
@org.junit.runner.RunWith（SpringJUnit4ClassRunner.class）
@SpringApplicationConfiguration（SpringbootJdbcDemoApplication.class）
公共类SpringbootJdbcDemoApplicationTests{
@自动连线
私有用户存储库用户存储库；
@org.junit.Test
公共无效findAllUsers（）{
List users=userRepository.findAll（）；
Assert.assertNotNull（用户）；
Assert.assertTrue（！users.isEmpty（））；
}
@试验
public void findUserById（）{
User=userRepository.findUserById（1）；
Assert.assertNotNull（用户）；
}
@试验
public void createUser（）{
用户=新用户（0，“John”john@gmail.com");
User savedUser=userRepository.create（用户）；
User newUser=userRepository.findUserById（savedUser.getId（））；
Assert.assertNotNull（newUser）；
Assert.assertEquals（“John”，newUser.getName（））；
Assert.assertEquals（“john@gmail.com，newUser.getEmail（））；
}
}

UserRepository.java

package edu.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootJdbcDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringbootJdbcDemoApplication.class, args);
    }
}

    package edu.demo;

    public class User{
        private Integer id;
        private String name;
        private String email;

    public User(int number, String strName, String strEmail){
        id = number;
        name = strName;
        email = strEmail;
    }

    public User(){

    }
    public Integer getId() {
        return id;
    }

    public String getEmail() {
        return email;
    }

    public String getName() {
        return name;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

package edu.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

import org.junit.*;

@org.junit.runner.RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(SpringbootJdbcDemoApplication.class)
public class SpringbootJdbcDemoApplicationTests {
        @Autowired
        private UserRepository userRepository;

        @org.junit.Test
        public void findAllUsers() {
                List<User> users = userRepository.findAll();
                Assert.assertNotNull(users);
                Assert.assertTrue(!users.isEmpty());
        }

        @Test
        public void findUserById() {
                User user = userRepository.findUserById(1);
                Assert.assertNotNull(user);
        }

        @Test
        public void createUser() {
                User user = new User(0, "John", "john@gmail.com");
                User savedUser = userRepository.create(user);
                User newUser = userRepository.findUserById(savedUser.getId());
                Assert.assertNotNull(newUser);
                Assert.assertEquals("John", newUser.getName());
                Assert.assertEquals("john@gmail.com", newUser.getEmail());
        }
}

包edu.demo；
导入org.springframework.beans.factory.annotation.Autowired；
导入org.springframework.boot.test.SpringApplicationConfiguration；
导入org.springframework.boot.test.context.SpringBootTest；
导入org.springframework.test.context.junit4.SpringJUnit4ClassRunner；
导入java.util.List；
导入org.junit.*；
@org.junit.runner.RunWith（SpringJUnit4ClassRunner.class）
@SpringApplicationConfiguration（SpringbootJdbcDemoApplication.class）
公共类SpringbootJdbcDemoApplicationTests{
@自动连线
私有用户存储库用户存储库；
@org.junit.Test
公共无效findAllUsers（）{
List users=userRepository.findAll（）；
Assert.assertNotNull（用户）；
Assert.assertTrue（！users.isEmpty（））；
}
@试验
public void findUserById（）{
User=userRepository.findUserById（1）；
Assert.assertNotNull（用户）；
}
@试验
public void createUser（）{
用户=新用户（0，“John”john@gmail.com");
User savedUser=userRepository.create（用户）；
User newUser=userRepository.findUserById（savedUser.getId（））；
Assert.assertNotNull（newUser）；
Assert.assertEquals（“John”，newUser.getName（））；
Assert.assertEquals（“john@gmail.com，newUser.getEmail（））；
}
}

是的，在pom中，您对

h2有依赖关系

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
</dependency>


com.h2数据库
. 或者改变它，或者简单地添加mysql（如果您也使用h2），以

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency> 


mysql
mysql连接器java
和我的解决方案：

步骤1：删除“mysql连接器”maven存储库：

rm -r ~/.m2/repository/mysql/mysql-connector-java

步骤2：将以下代码段添加到pom.xml中：

<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
</dependency>


mysql
mysql连接器java

第三步：保存项目，然后等待“构建工作区”完成，一切顺利。但是我不知道发生了什么…
如果您使用netbeans和hibernate framwork手动添加jdbc，请转到persistence.xml并转到design add jdbc connection，它对我来说很好
祝您好运
对于手动构建数据源的人员，除了加载
mysql连接器依赖项
，还要确保
驱动程序类名
设置正确

DataSourceFactory factory = new DataSourceFactory();
factory.setUrl("..");
factory.setUser("..");
factory.setDriverClass("com.mysql.jdbc.Driver"); //Important
...
DBI dbi = new DBI(factory.build(new MetricRegistry(), "mysql"));

否则，
DataSourceFactory.driverClass
实例字段将设置为
“”
。当应用程序类加载器尝试加载名为“
”
”的类时，它将抛出一个
ClassNotFoundException
，在我的pom文件中输入该代码会给我一个新错误：“com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障成功发送到服务器的最后一个数据包是0毫秒前的。驱动程序尚未从服务器收到任何数据包。“这确实是一个不同的问题，但是现在您有了mysql jdbc驱动程序，您需要将其配置为指向您的数据库。那通常在你的房间里。通过链接，数据源配置由
spring.DataSource.*
，
url
，
用户名
，
密码
和
驱动程序类名
中的外部配置属性控制。好的，我将查看您链接到@Elliott Frisch的页面。谢谢你的帮助。哦，天哪，那是很多代码！如果你把它的一部分拿出来，你还有同样的问题吗？在使用dropwizard框架时，我也遇到了非常类似的问题，我缺少带有值的配置，因此错误如下：
由：java.sql.SQLException:无法从ClassLoader加载类