解决Android studio 编译flutter项目 卡在Running Gradle task ‘assembleDebug‘ ——筑梦之路

用Android Stduio创建Flutter项目的时候，会出现各种问题，踩了一个又一个，最后编译的时候可能会出现一直显示Running Gradle task 'assembleDebug'然后就不动了，或者会显示Could not resolve io.flutter等问题，归根结底是网络无法访问flutter官方源引起的，两种解决方案：

1.具有比较良好的访问flutter官方源的网络环境

2.修改镜像源为国内的：

找到Flutte SDK目录下的Flutter打包配置文件flutter.gradle

路径为flutter\packages\flutter_tools\gradle\flutter.gradle

第一处配置：

buildscript {
    repositories {
//注释
        // google()
        // jcenter()
//添加
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
    }
}

第二处配置：

class FlutterPlugin implements Plugin<Project> {
//注释
    // private static final String MAVEN_REPO      = "https://storage.googleapis.com/download.flutter.io";
//添加这行
    private static final String MAVEN_REPO = "https://storage.flutter-io.cn/download.flutter.io";
 
    // The platforms that can be passed to the `--Ptarget-platform` flag.
    private static final String PLATFORM_ARM32  = "android-arm";
    private static final String PLATFORM_ARM64  = "android-arm64";
    private static final String PLATFORM_X86    = "android-x86";
    private static final String PLATFORM_X86_64 = "android-x64";
 
    // The ABI architectures.
    private static final String ARCH_ARM32      = "armeabi-v7a";
    private static final String ARCH_ARM64      = "arm64-v8a";
    private static final String ARCH_X86        = "x86";
    private static final String ARCH_X86_64     = "x86_64";

第三处配置：

void addFlutterDependencies(buildType) {
        String flutterBuildMode = buildModeFor(buildType)
        if (!supportsBuildMode(flutterBuildMode)) {
            return
        }
        String repository = useLocalEngine()
            ? project.property('local-engine-repo')
            : MAVEN_REPO
 
        project.rootProject.allprojects {
            repositories {
                maven {
                    url repository
                }
               //添加
                maven { url 'https://maven.aliyun.com/repository/google' }
                maven { url 'https://maven.aliyun.com/repository/jcenter' }
                maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }
            }
        }

最后一处，项目中的配置，修改Flutter项目下的android下的build.gradle：

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
//        google()
//        jcenter()
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }
    }
 
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}
 
allprojects {
    repositories {
//        google()
//        jcenter()
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }
    }
}

修改完成后，再build，就可以正常构建了！！！

我也查过很多资料，网上很多资料要么是gradle构建工具没下载下来，下载太慢，要么是修改了项目里面的配置，要么是修改全局的flutter.gradle配置，都还是存在一些问题，我通过修改这四处配置，成功运行。

全局环境变量：

PUB_HOSTED_URL            https://mirrors.tuna.tsinghua.edu.cn/dart-pub
FLUTTER_STORAGE_BASE_URL  https://mirrors.tuna.tsinghua.edu.cn/flutter

阿里云的仓库地址：

maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }

flutter SDK 清华大学镜像地址：

https://mirrors.tuna.tsinghua.edu.cn/flutter/flutter_infra/releases/stable/

修改resolve_dependencies.gradle

repositories {
    //google()
    //jcenter()
	maven { url 'https://maven.aliyun.com/repository/google' }
    maven { url 'https://maven.aliyun.com/repository/jcenter' }
    maven { url 'https://maven.aliyun.com/nexus/content/groups/public' }
    maven {
        url "$storageUrl/download.flutter.io"
    }
}

以上内容是自己经过实践总结所得，在此做个记录！

-----2022-7-27 

以上是内容环境是1.x，对于2.0以上的执行flutter doctor会报错：

HTTP host https://maven.google.com/ is not reachable.Reason: An error occurred while checking the HTTP host

解决办法：

修改flutter sdk目录下文件packages\flutter_tools\lib\src\http_host_validator.dart

# 1. 找到代码21-24行

/// Android specific required HTTP hosts.
const List<String> androidRequiredHttpHosts = <String>[
  'https://maven.google.com/',
];

# 将https://maven.google.com/ 修改为
# https://dl.google.com/dl/android/maven2/或者https://maven.aliyun.com/

/// Android specific required HTTP hosts.
const List<String> androidRequiredHttpHosts = <String>[
  'https://maven.aliyun.com/',
];

# 2. flutter sdk bin目录，删除cache目录下的flutter_tools.snapshot 文件

# 3. 新开cmd 重新运行flutter doctor

参考资料：

仓库服务

flutter | 镜像站使用帮助 | 清华大学开源软件镜像站 | Tsinghua Open Source Mirror