Travis CLI 上的 Spring Boot 测试失败并出现异常：com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Question

测试：HttpRequestTest

package hello;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
import org.springframework.test.context.junit4.SpringRunner;

import static org.assertj.core.api.Assertions.assertThat;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class HttpRequestTest {

    @LocalServerPort
    private int port;

    @Autowired
    private TestRestTemplate restTemplate;

    @Test
    public void test_message_test(){
        assertThat(true).isTrue();
}

错误：

[ERROR] Errors: 
[ERROR]   HttpRequestTest.test_message_test » IllegalState Failed to load ApplicationCon...
[INFO] 
[ERROR] Tests run: 51, Failures: 0, Errors: 1, Skipped: 0
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  26.265 s
[INFO] Finished at: 2019-06-21T08:32:34Z
[INFO] ------------------------------------------------------------------------

错误继续..

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2103) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46) ~[mysql-connector-java-5.1.6.jar:na]
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302) ~[mysql-connector-java-5.1.6.jar:na]
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282) ~[mysql-connector-java-5.1.6.jar:na]
    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.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at ...

更新：

Build system information
Build language: java
Build group: stable
Build dist: xenial
Build id: 116398441
Job id: 209903752
Runtime kernel version: 4.15.0-1028-gcp
travis-build version: 541266b83
Build image provisioning date and time
Mon Mar 25 16:43:24 UTC 2019
Operating System Details
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.6 LTS
Release:    16.04
Codename:   xenial
Systemd Version
systemd 229
Cookbooks Version
42e42e4 https://github.com/travis-ci/travis-cookbooks/tree/42e42e4
git version
git version 2.21.0
bash version
GNU bash, version 4.3.48(1)-release (x86_64-pc-linux-gnu)
gcc version
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.11) 5.4.0 20160609
docker version
Client:
 Version:           18.06.0-ce
 API version:       1.38
 Go version:        go1.10.3
 Git commit:        0ffa825
 Built:             Wed Jul 18 19:11:02 2018
 OS/Arch:           linux/amd64
 Experimental:      false
Server:
 Engine:
  Version:          18.06.0-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:       0ffa825
  Built:            Wed Jul 18 19:09:05 2018
  OS/Arch:          linux/amd64
  Experimental:     false

Answer 1

您在连接 MySQL 服务器时遇到问题。连接是作为 Web 应用程序启动的一部分设置的，因为 JPA 是大多数 Spring Boot Web 应用程序不可或缺的一部分，Spring Boot 试图在任何测试运行之前启动并运行它。

MySQL 服务器似乎无法访问。如果您对服务器地址进行了硬编码，并且它在您的本地服务器中运行（而不是在 Travis 的服务器上），请确保它正在接受来自 Linux 的 Travis IPs 的连接。也可以（但相对昂贵）在运行您的代码的同一实例中启动全新的 MySQL 服务器。

或者，由于这只是一个 Hello World 示例，请切换到嵌入式数据库进行测试。运气好的话，您只需将application.properties 更改为如下内容：

spring.datasource.username: sa
spring.datasource.password:
spring.jpa.properties.hibernate.dialect: org.hibernate.dialect.HSQLDialect
spring.jpa.database: HSQL
spring.datasource.url: jdbc:hsqldb:mem:iw;create=true 

并将该数据库（在上面的示例中为 HSQLDB）的必要依赖项添加到您的 pom.xml。

<dependency>
    <groupId>org.hsqldb</groupId>
    <artifactId>hsqldb</artifactId>
    <version>2.6.0</version>
    <scope>test</scope>
</dependency>