Android Studio从HTTPS下载附件及Outlook 365集成崩溃问题求助

Hey there! Let's break down your two technical needs and work through practical solutions for each issue—since you've already tried most Stack Overflow suggestions, I'll focus on less commonly mentioned but effective fixes.

First up, this task hinges on getting permissions right and avoiding main-thread IO operations. Here's a step-by-step breakdown:

• Step 1: Configure Required Permissions
  Add these to your AndroidManifest.xml (adjust based on your target SDK version):

  <!-- Core network permission -->
  <uses-permission android:name="android.permission.INTERNET" />
  <!-- Storage access for Android 12 and below -->
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="32" />
  <!-- Media-specific permissions for Android 13+ (tailor to your attachment types) -->
  <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
  <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
  <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
  

  Remember to request these permissions dynamically at runtime—don't assume they're granted automatically.

• Step 2: Use OkHttp for HTTPS Downloads (Recommended)
  OkHttp simplifies HTTPS handling and avoids boilerplate code. First add the dependency to your build.gradle (Module level):

  implementation 'com.squareup.okhttp3:okhttp:4.12.0'
  

  Then implement the download logic in a background thread (using Kotlin Coroutines here for modern Android development):

  lifecycleScope.launch(Dispatchers.IO) {
      val targetUrl = "https://your-https-domain.com/your-attachment.pdf"
      val okHttpClient = OkHttpClient()
  
      try {
          val request = Request.Builder().url(targetUrl).build()
          okHttpClient.newCall(request).execute().use { response ->
              if (!response.isSuccessful) throw IOException("Unexpected response code: $response")
              
              // Use app-specific storage (no runtime permission needed) to avoid permission issues
              val saveFile = File(getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS), "downloaded_file.pdf")
              response.body?.byteStream()?.use { inputStream ->
                  FileOutputStream(saveFile).use { outputStream ->
                      inputStream.copyTo(outputStream) // Stream data to file to avoid OOM
                  }
              }
  
              // Switch back to main thread to update UI
              withContext(Dispatchers.Main) {
                  Toast.makeText(this@YourActivity, "Download completed!", Toast.LENGTH_SHORT).show()
              }
          }
      } catch (e: Exception) {
          e.printStackTrace()
          withContext(Dispatchers.Main) {
              Toast.makeText(this@YourActivity, "Download failed: ${e.message}", Toast.LENGTH_SHORT).show()
          }
      }
  }
  

  Note: If you're dealing with self-signed HTTPS certificates, you'll need to add custom certificate trust logic to OkHttp—but avoid this in production if possible.

Since you can already access accounts and view emails, your OAuth setup and mail list API calls are working. The crash is almost certainly tied to how you handle attachment streams, permissions, or thread execution. Try these targeted fixes:

• Verify Graph API Attachment Endpoint Usage
  For large attachments (over 4MB), direct downloads will cause OOM crashes. Use the @microsoft.graph.downloadUrl provided by the Graph API instead of fetching the attachment directly. Example code:

  lifecycleScope.launch(Dispatchers.IO) {
      val messageId = "your-target-message-id"
      val attachmentId = "your-target-attachment-id"
  
      try {
          // First fetch attachment metadata to get the download URL
          val attachment = graphClient.me().messages(messageId).attachments(attachmentId).get().execute()
          val downloadUrl = attachment.additionalData["@microsoft.graph.downloadUrl"] as String
  
          // Use OkHttp to download from the dedicated URL
          val client = OkHttpClient()
          val request = Request.Builder().url(downloadUrl).build()
          client.newCall(request).execute().use { response ->
              if (!response.isSuccessful) throw IOException("Graph API download failed: $response")
              
              val saveFile = File(getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS), attachment.name)
              response.body?.byteStream()?.use { input ->
                  FileOutputStream(saveFile).use { output ->
                      input.copyTo(output) // Stream to file to prevent memory overload
                  }
              }
  
              withContext(Dispatchers.Main) {
                  Toast.makeText(this@YourActivity, "Attachment saved!", Toast.LENGTH_SHORT).show()
              }
          }
      } catch (e: Exception) {
          e.printStackTrace()
          withContext(Dispatchers.Main) {
              Toast.makeText(this@YourActivity, "Attachment download crashed: ${e.message}", Toast.LENGTH_SHORT).show()
          }
      }
  }
  

• Enforce Background Thread Execution
  Never perform file writing or network calls on the main thread—this is a top cause of crashes and ANRs. The code above uses Dispatchers.IO to ensure all heavy work runs off the main thread.

• Catch All Explicitly
  Missing exception handling can hide the root cause of crashes. Wrap all download and file operations in a try-catch block and log the full stack trace—this will tell you if the issue is permission-related, network-related, or an out-of-memory error.

• Check Storage Permissions
  If you're saving attachments to public storage directories (not app-specific folders), ensure you've requested and been granted the appropriate runtime permissions. For Android 13+, this means READ_MEDIA_* permissions or the special MANAGE_EXTERNAL_STORAGE permission (which requires directing users to system settings).

• Avoid Memory Overload
  Always stream attachment data directly to a file instead of loading the entire attachment into memory. Using byteStream() and copyTo() (as shown in code examples) prevents OOM crashes with large files.

内容的提问来源于stack exchange，提问作者Kaan Çağhan