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

Test: 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();
}

Error:

[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] ------------------------------------------------------------------------

Error Cont..

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 ...

Update:

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

You are having problems connecting with a MySQL server. The connection is being set up as part of your web application's startup, because JPA is an integral part of most Spring Boot web applications, and Spring Boot is trying to get it up and running before any tests can be run.

The MySQL server appears to be unreachable. If you have hard-coded the server address, and it is running in your local servers (and not on Travis' servers), make sure that it is accepting connections from the Travis IPs for Linux. It is also possible (but relatively expensive) to launch a brand-new MySQL server in the same instance that is running your code.

Alternatively, since this is just a Hello World example, switch to an embedded DB for your tests. With any luck, you will only need to change your application.properties to something such as the following:

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 

And add the necessary dependencies for that DB (in the above example, HSQLDB) to your pom.xml .

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