Question

我正在尝试将Spring引导项目构建为JAR文件。在我的项目中，我使用本地MySQL数据库存储数据，但现在我的项目已完成并准备在Linux服务器上启动它，但是当我从application.properties更改了MySQL连接信息，而maven无法打包该项目，并且出现此错误

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81) ~[spring-jdbc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
    at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:319) ~[spring-jdbc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
    ... 88 common frames omitted
Caused by: com.mysql.cj.jdbc.exceptions.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 com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207) ~[mysql-connector-java-8.0.13.jar:8.0.13]
    at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-3.2.0.jar:na]
    at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.2.0.jar:na]
    at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) ~[spring-jdbc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
    at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) ~[spring-jdbc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
    at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) ~[spring-jdbc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
    ... 89 common frames omitted
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

这是我的行家pom.xml：

<?xml version="1.0" encoding="UTF-8"?>

http://maven.apache.org/xsd/maven-4.0.0.xsd“> 4.0.0

<groupId>test</groupId>
<artifactId>TransApplication</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>test</name>
<description>test</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.1.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>
    <start-class>com.trans.co.TransApplication.TransApplication</start-class>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-rest</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
    </dependency>


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

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

    <dependency>
        <groupId>com.squareup.retrofit2</groupId>
        <artifactId>retrofit</artifactId>
        <version>2.3.0</version>
    </dependency>


    <dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>logging-interceptor</artifactId>
        <version>3.12.0</version>
    </dependency>
    <dependency>
        <groupId>com.squareup.retrofit2</groupId>
        <artifactId>converter-gson</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.16.22</version>
    </dependency>
</dependencies>

<build>

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <transformers>
                            <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass>package.Main</mainClass>
                            </transformer>
                        </transformers>
                    </configuration>
                </execution>
            </executions>
        </plugin>

        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <executable>true</executable>
            </configuration>
        </plugin>
    </plugins>
</build>

我唯一的问题是一个简单的更改，我想更改服务器上的连接信息

Answer 1

在项目的Test类上对此// @ SpringBootTest进行注释

Answer 2

根据您的描述

maven无法打包项目

这表明Spring Boot Uber Jar没有打包，因为Maven生命周期中的测试阶段失败了。一般来说，在将Boot Jar部署到服务器之前，应先对其进行打包/组装，这样就不必担心测试失败。

如果要在服务器上构建该服务器，以建议从那里生成Boot Jar工件，则表明您定义的数据源配置在该环境中不适用或不正确。您将需要跳过需要本地数据源的测试，或者提供一个数据源以使您的测试成功。

Spring Boot提供了一个强大的配置管理系统，该系统可以根据环境进行调整，甚至可以通过运行上下文来运行。实际上，您已经在使用它，并根据更改application.properties文件的描述将其设置为使用。

详细信息here。特别是，请注意描述属性源评估顺序的部分，因为这使您能够根据部署情况调整属性。

有许多可供选择的选项，但是总的来说，我让我的开发团队将内置在jar中的application.properties文件（默认情况下是从主要资源源集）配置为在默认开发环境中工作。开发人员还可以在他们的开发环境的工作目录中放置一个application.properties文件，以根据他们的开发环境覆盖这些设置。也可以以相同的方式在构建系统或服务器上提供属性。通过环境变量或profiles来定义它们也很方便，Spring Cloud Config可以基于活动配置文件配置属性来定义它们的大集合。大型/扩展基础架构也可以从{{3}}中受益，从而进一步简化此管理。

从带有外部数据库连接的spring项目构建jar文件

2 个答案: