AssetExtractor code

AssetExtractor.java

package com.google.appinventor.components.runtime;
 
import android.content.res.AssetManager;
import android.os.Environment;
import com.google.appinventor.components.annotations.*;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.common.PropertyTypeConstants;
import com.google.appinventor.components.common.YaVersion;
import com.google.appinventor.components.runtime.util.FileUtil;
 
import java.io.File;
import java.io.*;
 
@DesignerComponent(version = YaVersion.ASSETS_EXTRACTOR_COMPONENT_VERSION,
        description = "Non-visible component that extracts file from the assets to the storage " +
                "files.",
        category = ComponentCategory.STORAGE,
        nonVisible = true,
        iconName = "images/file.png")
@SimpleObject
@UsesPermissions(permissionNames = "android.permission.WRITE_EXTERNAL_STORAGE, android.permission.READ_EXTERNAL_STORAGE")
public class AssetExtractor extends AndroidNonvisibleComponent {
 
    private String filePath = "";  // Picture property
 
    public AssetExtractor(ComponentContainer container) {
        super(container.$form());
    }
 
    /**
     * Takes file from the assets folder and then asynchronously writes it
     * to external storage. This allows to share files between apps.
     */
    @SimpleFunction(description = "Takes file from the assets folder and then asynchronously writes it" +
            "to external storage. This allows to share files between apps")
    public void ExtractFile() {
        FileUtil.checkExternalStorageWriteable();
        copyAssets(filePath, filePath);
    }
 
    @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_ASSET, defaultValue = "")
    @SimpleProperty
    public void File(String path) {
        filePath = (path == null) ? "" : path;
    }
 
 
    /**
     * Event indicating that a request has finished.
     *
     * @param fileUri read from the file
     */
    @SimpleEvent(description = "Event indicating that the contents from the file have been copied to the file system.")
    public void FileExtracted(String fileUri) {
        EventDispatcher.dispatchEvent(this, "FileExtracted", fileUri);
    }
 
 
    private void copyAssets(String filePath, String outFileName) {
        AssetManager assetManager = form.getBaseContext().getAssets();
        InputStream in = null;
        OutputStream out = null;
        File outFile = null;
        try {
            in = assetManager.open(filePath);
            outFile = new File(Environment.getExternalStorageDirectory(), outFileName);
            out = new FileOutputStream(outFile);
            copyFile(in, out);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        FileExtracted(outFile.getAbsolutePath());
    }
 
    private void copyFile(InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[1024];
        int read;
        while ((read = in.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }
    }
}