Travis CLI 上的 Spring Boot 测试失败，出现异常：com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：通信链接失败

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。 连接被设置为 Web 应用程序启动的一部分，因为 JPA 是大多数 Spring Boot Web 应用程序的组成部分，并且 Spring Boot 试图在运行任何测试之前启动并运行它。

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上运行（而不是在 Travis 的服务器上），请确保它接受来自 Linux 的Travis IP 的连接。 也可以（但相对昂贵）在运行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，您只需要将application.properties更改为以下内容：

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 

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

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