maven 无法从中央下载 mysql 连接器 8.0.12

Question

Maven 无法从中央下载 mysql 连接器 8.0.12，显示以下错误：

---

Downloading: https://repo.maven.apache.org/maven2/mysql/mysql-connector- 
java/8.0.12/mysql-connector-java-8.0.12.pom
[INFO] ---------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ---------------------------------------------------------------------
[INFO] Total time: 3.642 s
[INFO] Finished at: 2018-08-21T00:22:03+05:30
[INFO] Final Memory: 10M/113M
[INFO] ---------------------------------------------------------------------
[ERROR] Failed to execute goal on project OneSolution: Could not resolve 
dependencies for project OneSolution:OneSolution:jar:1.1.1: Failed to 
collect dependencies at mysql:mysql-connector-java:jar:8.0.12: Failed to 
read artifact descriptor for mysql:mysql-connector-java:jar:8.0.12: Could 
not transfer artifact mysql:mysql-connector-java:pom:8.0.12 from/to central 
(https://repo.maven.apache.org/maven2): Received fatal alert: 
protocol_version -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e 
switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.

---

感谢任何帮助，没有在网上获得足够的建议，在这里尝试。

Answer 1

Solution 1:

在控制台中尝试

mvn clean install

。

Solution 2:

这可能是因为您计算机上的防火墙。关闭防火墙并重试。

Solution 3:

检查您的

pom.xml

是否有类似的依赖。

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.12</version>
</dependency>

Answer 2

如果您使用的是 intelliJ idea，还有一个选项：

在 Maven 工具窗口中，单击“切换离线模式”按钮。

这会将 --offline 选项附加到 IntelliJ IDEA 运行的所有 Maven 命令。它还将报告在本地存储库中找不到的任何项目。

或者在 Maven settings.xml 中：

<offline>false</offline>

Answer 3

在 maven 中使用这种方式：

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.12</version> 
</dependency>

Answer 4

<dependency>
  <groupId>com.mysql</groupId>
  <artifactId>mysql-connector-j</artifactId>
  <scope>runtime</scope>
</dependency>