过去几天我试图在我自己的服务器上在线获取Spring Boot Application。我在那里安装了MySql和Tomcat。它之前也使用过数据库连接，但是由于某些原因，我的新版本不再起作用了。
我的application.properties如下：
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.datasource.url=jdbc:mysql://localhost:3306/dbacc
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.h2.console.enabled=true
应用程序确实启动了，但是当我尝试向我的数据库添加新记录时，我收到以下消息：
Unable to acquire JDBC Connection; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
有人可以帮我解决这个问题吗？提前谢谢。
控制器的一部分：
@RequestMapping(value = "/registration", method = RequestMethod.GET)
public String registration(Model model) {
System.out.println("in methode registration (29)");
model.addAttribute("userForm", new Client());
return "registration";
}
@RequestMapping(value = "/registration", method = RequestMethod.POST)
public String registration(@ModelAttribute("userForm") Client userForm, BindingResult bindingResult, Model model) {
System.out.println("in methode registration (37)");
clientValidator.validate(userForm, bindingResult);
if (bindingResult.hasErrors()) {
return "registration";
}
clientService.save(userForm);
securityService.autologin(userForm.getCompanyName(), userForm.getPasswordConfirm());
return "redirect:/welcome";
}
客户端模型：
@Entity
public class Client {
private Long id;
private String companyName;
private String password;
private String passwordConfirm;
private String addressStreet;
private Long addressNumber;
private String addressNumberAdd;
private String zipCode;
private String city;
private String personToContact;
private String phoneNumber;
private String email;
//getters and setters
}
的pom.xml
<?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>
<groupId>nl.insiteweb</groupId>
<artifactId>insite</artifactId>
<packaging>war</packaging>
<name>insiteweb</name>
<description>Accountancy systeem voor Insiteweb</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>cleanup</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>typography</artifactId>
<version>1.0.2</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>zugferd</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>html2pdf</artifactId>
<version>1.0.0</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext-licensekey</artifactId>
<version>2.0.3</version>
</dependency>
<dependency>
<groupId>com.itextpdf.tool</groupId>
<artifactId>xfaworker</artifactId>
<version>5.5.10</version>
</dependency>
<dependency>
<groupId>com.itextpdf.tool</groupId>
<artifactId>itext-licensekey</artifactId>
<version>1.0.4</version>
</dependency>
<dependency>
<groupId>org.opensaml</groupId>
<artifactId>opensaml</artifactId>
<version>2.6.4</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
</dependency>
<dependency>
<groupId>net.sf.ehcache</groupId>
<artifactId>ehcache-core</artifactId>
<version>2.2.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</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>
<repositories>
<repository>
<id>itext</id>
<name>iText Repository - releases</name>
<url>https://repo.itextsupport.com/releases</url>
</repository>
<repository>
<id>iText Repository</id>
<name>iText Repository-releases</name>
<url>https://repo.itextsupport.com/releases</url>
</repository>
</repositories>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.2.RELEASE</version>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<sources>
<source>facturen/</source>
</sources>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
我从logs / catalina.out
获得的错误Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:341) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2251) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:732) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:664) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:479) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) ~[tomcat-jdbc-8.5.11.jar:na]
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) ~[tomcat-jdbc-8.5.11.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:386) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:87) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
... 132 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_121]
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_121]
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_121]
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_121]
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_121]
at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_121]
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211) ~[mysql-connector-java-5.1.40.jar:5.1.40]
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:300) ~[mysql-connector-java-5.1.40.jar:5.1.40]
... 156 common frames omitted