Gradle构建从Maven仓库下载依赖失败，但直接下载成功

问题描述 #

使用Gradle从Maven中央仓库下载依赖时频繁触发超时，报错示例如下：

Could not download log4j-core-2.17.1.jar (org.apache.logging.log4j:log4j-core:2.17.1)
> Could not get resource 'https://repo.maven.apache.org/maven2/org/apache/logging/log4j/log4j-core/2.17.1/log4j-core-2.17.1.jar'.
> Could not GET 'https://repo.maven.apache.org/maven2/org/apache/logging/log4j/log4j-core/2.17.1/log4j-core-2.17.1.jar'.
> Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.40.215] failed: Read timed out
Could not download log4j-api-2.17.1.jar (org.apache.logging.log4j:log4j-api:2.17.1)
> Could not get resource 'https://repo.maven.apache.org/maven2/org/apache/logging/log4j/log4j-api/2.17.1/log4j-api-2.17.1.jar'.
> Could not GET 'https://repo.maven.apache.org/maven2/org/apache/logging/log4j/log4j-api/2.17.1/log4j-api-2.17.1.jar'.
> Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.40.215] failed: Read timed out
Could not download commons-configuration2-2.2.jar (org.apache.commons:commons-configuration2:2.2)
> Could not get resource 'https://repo.maven.apache.org/maven2/org/apache/commons/commons-configuration2/2.2/commons-configuration2-2.2.jar'.
> Could not GET 'https://repo.maven.apache.org/maven2/org/apache/commons/commons-configuration2/2.2/commons-configuration2-2.2.jar'.
> Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.40.215] failed: Read timed out
Could not download jersey-apache-connector-2.26.jar (org.glassfish.jersey.connectors:jersey-apache-connector:2.26)
> Could not get resource 'https://repo.maven.apache.org/maven2/org/glassfish/jersey/connectors/jersey-apache-connector/2.26/jersey-apache-connector-2.26.jar'.
> Could not HEAD 'https://repo.maven.apache.org/maven2/org/glassfish/jersey/connectors/jersey-apache-connector/2.26/jersey-apache-connector-2.26.jar'.
> Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.40.215] failed: Read timed out

但使用wget直接下载这些包可成功，以下是可行的解决方法：

解决方法 #

1. 延长Gradle网络超时时间 #

Gradle默认的网络超时阈值较短，国内网络环境下易触发超时。在项目根目录的gradle.properties中添加以下配置（设置为5分钟）：

org.gradle.internal.http.connectionTimeout=300000
org.gradle.internal.http.socketTimeout=300000

2. 切换至国内Maven镜像 #

替换中央仓库为国内镜像（如阿里云），大幅提升下载速度。修改项目的build.gradle文件：

repositories {
    maven { url 'https://maven.aliyun.com/repository/public' }
    mavenCentral()
}

若需全局配置所有项目，修改settings.gradle文件：

pluginManagement {
    repositories {
        maven { url 'https://maven.aliyun.com/repository/public' }
        gradlePluginPortal()
    }
}
dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        maven { url 'https://maven.aliyun.com/repository/public' }
    }
}

3. 检查并禁用不必要的代理 #

如果Gradle配置了代理但实际不需要，会导致连接异常。打开gradle.properties，注释掉代理相关配置：

# systemProp.http.proxyHost=proxy.example.com
# systemProp.http.proxyPort=8080
# systemProp.https.proxyHost=proxy.example.com
# systemProp.https.proxyPort=8080

4. 手动下载依赖至本地仓库 #

利用wget下载对应jar包后，放置到本地Maven仓库的对应路径。例如log4j-core-2.17.1.jar的路径为：

~/.m2/repository/org/apache/logging/log4j/log4j-core/2.17.1/

Gradle会优先读取本地仓库中的依赖。

5. 清理Gradle缓存并刷新依赖 #

缓存损坏可能导致下载异常，执行以下命令清理缓存并重新下载：

./gradlew clean build --refresh-dependencies

也可手动删除Gradle缓存目录（需注意备份）：

rm -rf ~/.gradle/caches

内容的提问来源于stack exchange，提问作者Queenie Wong