Flutter项目运行报错：Java代码使用废弃API及资源链接失败

问题情况 #

• 我fork了一个包含MusicKit Plugin原生Java代码的Flutter项目
• 运行时出现构建失败，同时提示Java代码使用了废弃API

构建报错信息 #

Note: C:\Users\angel\Desktop\flutter_music_kit\flutter_musickit\android\src\main\java\com\zivost\musickit\MusickitPlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:processDebugResources'.
> Android resource linking failed
  C:\Users\angel\.gradle\caches\transforms-1\files-1.1\core-1.6.0.aar\11c6125161db973e0f4388722c28df2b\res\values\values.xml:192:5-228:25: AAPT: error: resource android:attr/fontVariationSettings not found.

  C:\Users\angel\.gradle\caches\transforms-1\files-1.1\core-1.6.0.aar\11c6125161db973e0f4388722c28df2b\res\values\values.xml:192:5-228:25: AAPT: error: resource android:attr/ttcIndex not found.

  error: failed linking references.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 39s
Exception: Gradle task assembleDebug failed with exit code 1

涉及的Java代码 #

package com.zivost.musickit;

import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;
import io.flutter.plugin.common.PluginRegistry.Registrar;

/** MusickitPlugin */
public class MusickitPlugin implements MethodCallHandler {
  /** Plugin registration. */
  public static void registerWith(Registrar registrar) {
    final MethodChannel channel = new MethodChannel(registrar.messenger(), "musickit");
    channel.setMethodCallHandler(new MusickitPlugin());
  }

  @Override
  public void onMethodCall(MethodCall call, Result result) {
      result.notImplemented();
  }
}

解决方案 #

1. 解决Android资源链接错误（构建失败核心原因） #

fontVariationSettings和ttcIndex是Android API 26（Android 8.0）引入的属性，需确保项目SDK版本达标：

• 打开android/app/build.gradle文件
• 修改compileSdkVersion和targetSdkVersion为26或更高版本，示例：

  android {
      compileSdkVersion 34
      defaultConfig {
          targetSdkVersion 34
          // 保留其他原有配置
      }
  }
  

• 同步Gradle后重新构建

2. 修复废弃API问题 #

原代码使用的registerWith(Registrar)是Flutter旧版插件注册方式，已被废弃，替换为新的嵌入v2实现：

• 更新Java代码为：

  package com.zivost.musickit;
  
  import io.flutter.embedding.engine.plugins.FlutterPlugin;
  import io.flutter.plugin.common.MethodCall;
  import io.flutter.plugin.common.MethodChannel;
  import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
  import io.flutter.plugin.common.MethodChannel.Result;
  
  /** MusickitPlugin */
  public class MusickitPlugin implements FlutterPlugin, MethodCallHandler {
    private MethodChannel channel;
  
    @Override
    public void onAttachedToEngine(FlutterPlugin.FlutterPluginBinding flutterPluginBinding) {
      channel = new MethodChannel(flutterPluginBinding.getBinaryMessenger(), "musickit");
      channel.setMethodCallHandler(this);
    }
  
    @Override
    public void onMethodCall(MethodCall call, Result result) {
        result.notImplemented();
    }
  
    @Override
    public void onDetachedFromEngine(FlutterPlugin.FlutterPluginBinding binding) {
      channel.setMethodCallHandler(null);
    }
  }
  

• 打开android/src/main/AndroidManifest.xml，将原插件注册的meta-data替换为：

  <meta-data
      android:name="flutterEmbedding"
      android:value="2" />
  

内容的提问来源于stack exchange，提问作者Harvey Jones