我目前正在学习有关在Spring Boot webapp中实现JDBC和使用数据库的更多信息，并且在帖子底部遇到了以下堆栈跟踪。

我创建了一个简单的Employee模型，并且试图在main（）所在的同一类上执行一些数据库代码。该模型和main类是整个项目中仅有的两个Java文件。我正在尝试实现以下run（）代码，该代码将覆盖CommandLineRunner接口中的代码，但我没有得到
log.info（“ Part A：”） 之后的日志：

log.info("Part A:")
employees.forEach(employee -> {log.info(employee.toString());
        log.info("part a");});

-我注意到的事情：

我注意到，堆栈跟踪开始之前的日志最后一行来自：“ Thread-1”而不是“
main”。我认为这意味着来自非主要线程的线程在应正常关闭之前遇到错误并关闭了连接。

另外，我认为因为 HikariPool在“ peer’s close_notify”之前关闭
，我认为这是指HikariPool的正常关闭，所以我看不到我一直试图进行的最后一次日志记录。我要查看的日志记录的最后一部分是已插入到数据库中的员工的日志记录。

我想查看的日志记录的最后一部分应从以下代码行获得：

employees.forEach(employee -> {log.info(employee.toString());
        log.info("part a");});

-注意事项：

由于日志中有这一行，我以为我会看到该雇员插入了我的数据库，但是当我直接在MySQL Command Line Client上查询时，它返回了一个空集：

2018-11-03 21:08:35.362  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : rows affected: 1

我不明白为什么 什么都没有插入到数据库中时，行会受到影响 。

stacktrace和日志：（下面粘贴的stacktrace实际上会重复多次，但是为了简洁起见，我将其切除。）

2018-11-03 21:08:32.997  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Starting JdbcTest1Application on KitKat with PID 2408 (C:\Users\Nano\Downloads\jdbc-test1\jdbc-test1\target\classes started by Nano in C:\Users\Nano\Downloads\jdbc-test1\jdbc-test1)
2018-11-03 21:08:33.003  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : No active profile set, falling back to default profiles: default
2018-11-03 21:08:33.770  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Started JdbcTest1Application in 1.024 seconds (JVM running for 1.778)
2018-11-03 21:08:33.770  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Creating tables
2018-11-03 21:08:33.770  INFO 2408 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2018-11-03 21:08:34.082  INFO 2408 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
2018-11-03 21:08:35.135  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Inserting Baggins Hopkins
2018-11-03 21:08:35.362  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : rows affected: 1
2018-11-03 21:08:35.362  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Querying for employee
2018-11-03 21:08:36.065  INFO 2408 --- [           main] c.j.jdbctest1.JdbcTest1Application       : Part A:
2018-11-03 21:08:36.065  INFO 2408 --- [       Thread-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
Sat Nov 03 21:08:36 KST 2018 WARN: Caught while disconnecting...

EXCEPTION STACK TRACE:



** BEGIN NESTED EXCEPTION **

javax.net.ssl.SSLException
MESSAGE: closing inbound before receiving peer's close_notify

STACKTRACE:

javax.net.ssl.SSLException: closing inbound before receiving peer's close_notify
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:129)
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:117)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:308)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:264)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:255)
    at java.base/sun.security.ssl.SSLSocketImpl.shutdownInput(SSLSocketImpl.java:645)
    at java.base/sun.security.ssl.SSLSocketImpl.shutdownInput(SSLSocketImpl.java:624)
    at com.mysql.cj.protocol.a.NativeProtocol.quit(NativeProtocol.java:1312)
    at com.mysql.cj.NativeSession.quit(NativeSession.java:182)
    at com.mysql.cj.jdbc.ConnectionImpl.realClose(ConnectionImpl.java:1750)
    at com.mysql.cj.jdbc.ConnectionImpl.close(ConnectionImpl.java:720)
    at com.zaxxer.hikari.pool.PoolBase.quietlyCloseConnection(PoolBase.java:135)
    at com.zaxxer.hikari.pool.HikariPool.lambda$closeConnection$1(HikariPool.java:441)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)


** END NESTED EXCEPTION **

Java代码：

@SpringBootApplication
public class JdbcTest1Application implements CommandLineRunner {
    private static final Logger log = LoggerFactory.getLogger(JdbcTest1Application.class);

    @Autowired
    JdbcTemplate jdbcTemplate;

    public static void main(String[] args) {
        SpringApplication.run(JdbcTest1Application.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        log.info("Creating tables");

        jdbcTemplate.execute("DROP TABLE IF EXISTS employees");
        jdbcTemplate.execute("CREATE TABLE employees (emp_id int, name varchar(100), role varchar(100), status varchar(100))");

        log.info("Inserting Baggins Hopkins");
        int rowsAffected = jdbcTemplate.update("INSERT INTO EMPLOYEE(EMP_ID, NAME, ROLE, STATUS)"
                + " VALUES(1,'Baggins Hopkins','thief','WORKING')");
        log.info("rows affected: "+ Integer.toString(rowsAffected));
        log.info("Querying for employee");
        String sql = "SELECT emp_id,name,role,status FROM employees";
        List<Employee> employees = jdbcTemplate.query(sql,(rs, rowNum)-> 
        new Employee(rs.getInt("emp_id"), rs.getString("name"),
                rs.getString("role"),Status.valueOf(rs.getString("status"))));
        log.info("Part A:");
        employees.forEach(employee -> {log.info(employee.toString());
            log.info("part a");});

    }
}

同样以防万一，我从application.properties中粘贴了以下代码：

spring.datasource.url=jdbc:mysql://localhost:3306/employee_database
spring.datasource.username=employee
spring.datasource.password=employee
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver