maven報錯：Return code is: 501 , ReasonPhrase:HTTPS Required

今天把一個去年沒作完的項目翻出來作時，發現maven沒法正常導入依賴。檢查了一遍項目配置，沒發現有什麼問題。並且依賴在本地倉庫存在。

隨後發現報錯：Failed to transfer file:*********. Return code is: 501 , ReasonPhrase:HTTPS Required. 這時候好像發現了什麼重點————咱們須要將maven配置修改一下：

        <!-- 中央倉庫1 -->
        <mirror>
            <id>repo1</id>
            <mirrorOf>central</mirrorOf>
            <name>Human Readable Name for this Mirror.</name>
            <url>https://repo1.maven.org/maven2/</url>
        </mirror>

        <!-- 中央倉庫2 -->
        <mirror>
            <id>repo2</id>
            <mirrorOf>central</mirrorOf>
            <name>Human Readable Name for this Mirror.</name>
            <url>https://repo2.maven.org/maven2/</url>
        </mirror>

隨後發現能夠正常導入依賴了。

在stackoverflow上查了下，發現有人也遇到了這個問題：

Recently Maven build jobs running in Jenkins are failing with the below exception saying that they could not pull dependencies from Maven Central and should use HTTPS. I am not sure how to change the requests from HTTP to HTTPS. Could someone guide me on this matter?

回答以下：

Effective January 15, 2020, The Central Repository no longer supports insecure communication over plain HTTP and requires that all requests to the repository are encrypted over HTTPS.

因此這個問題的根源就是maven中央倉庫如今只支持HTTPS協議，咱們改一下就行。