store and install assets on android

android/build.gradle

@@ -37,6 +37,7 @@ android {
             java.srcDirs = ['src']
             res.srcDirs = ['res']
             jniLibs.srcDirs = ['libs']
+            assets.srcDirs = ['assets']
         }
     }
     signingConfigs {

android/src/org/purplei2p/i2pd/I2PDActivity.java

@@ -1,5 +1,10 @@
 package org.purplei2p.i2pd;
 
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.Timer;
@@ -10,7 +15,9 @@ import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.ServiceConnection;
+import android.content.res.AssetManager;
 import android.os.Bundle;
+import android.os.Environment;
 import android.os.IBinder;
 import android.util.Log;
 import android.view.Menu;
@@ -72,6 +79,12 @@ public class I2PDActivity extends Activity {
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		
+		// copy assets
+		copyAsset("certificates");
+		copyAsset("i2pd.conf");
+		copyAsset("subsciptions.txt");
+		copyAsset("tunnels.conf");
+		
 		textView = new TextView(this);
 		setContentView(textView);
 		daemon.addStateChangeListener(daemonStateUpdatedListener);
@@ -282,4 +295,65 @@ public class I2PDActivity extends Activity {
 	private static void setGracefulQuitTimer(Timer gracefulQuitTimer) {
 		I2PDActivity.gracefulQuitTimer = gracefulQuitTimer;
 	}
+	
+	/**
+		* Copy the asset at the specified path to this app's data directory. If the
+		* asset is a directory, its contents are also copied.
+		* 
+		* @param path
+		* Path to asset, relative to app's assets directory.
+	*/
+	private void copyAsset(String path) {
+		AssetManager manager = getAssets();
+		
+		// If we have a directory, we make it and recurse. If a file, we copy its
+		// contents.
+		try {
+			String[] contents = manager.list(path);
+			
+			// The documentation suggests that list throws an IOException, but doesn't
+			// say under what conditions. It'd be nice if it did so when the path was
+			// to a file. That doesn't appear to be the case. If the returned array is
+			// null or has 0 length, we assume the path is to a file. This means empty
+			// directories will get turned into files.
+			if (contents == null || contents.length == 0)
+			throw new IOException();
+			
+			// Make the directory.
+			File dir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/i2pd/", path);
+			dir.mkdirs();
+			
+			// Recurse on the contents.
+			for (String entry : contents) {
+				copyAsset(path + "/" + entry);
+			}
+			} catch (IOException e) {
+			copyFileAsset(path);
+		}
+	}
+	
+	/**
+		* Copy the asset file specified by path to app's data directory. Assumes
+		* parent directories have already been created.
+		* 
+		* @param path
+		* Path to asset, relative to app's assets directory.
+	*/
+	private void copyFileAsset(String path) {
+		File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/i2pd/", path);
+		try {
+			InputStream in = getAssets().open(path);
+			OutputStream out = new FileOutputStream(file);
+			byte[] buffer = new byte[1024];
+			int read = in.read(buffer);
+			while (read != -1) {
+				out.write(buffer, 0, read);
+				read = in.read(buffer);
+			}
+			out.close();
+			in.close();
+			} catch (IOException e) {
+			Log.e(TAG, "", e);
+		}
+	}
 }