Android開發中使用FileDownloader來實現檔案下載功能（總結一）
阿新 • • 發佈：2019-02-01
今天研究了一下Android開發中檔案下載功能，記錄一下。
這篇部落格主要介紹第三方下載外掛：FileDownloader的單任務的使用方法，至於多工的後面會做補充記錄，再寫一篇博文。
效果圖如下：（虛擬機器連不上網）
1、首先是引用方法：
implementation 'com.liulishuo.filedownloader:library:1.7.4'2、佈局檔案activity_test.xml如下：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:padding="5dp" xmlns:android="http://schemas.android.com/apk/res/android"> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/SecondDownLoad_tvDownLoadFileName"android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="下載檔名稱" android:layout_alignParentLeft="true" android:textStyle="bold" android:textSize="12dp" android:padding="10dp"/> <TextView android:id="@+id/SecondDownLoad_tvDownLoadSpeed" android:layout_width="wrap_content"android:layout_height="wrap_content" android:text="下載速度" android:textStyle="bold" android:textSize="12dp" android:layout_toLeftOf="@+id/SecondDownLoad_tvDownLoadDetail" android:layout_marginRight="10dp" android:padding="10dp"/> <TextView android:id="@+id/SecondDownLoad_tvDownLoadDetail" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="檔案詳情" android:textStyle="bold" android:textSize="12dp" android:layout_alignParentRight="true" android:padding="10dp"/> </RelativeLayout> <LinearLayout android:layout_marginTop="10dp" android:id="@+id/SecondDownLoad_lLayoutDownLoad" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <ProgressBar android:id="@+id/SecondDownLoad_pBarProgress" style="@style/Widget.AppCompat.ProgressBar.Horizontal" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_weight="1"/> <Button android:id="@+id/SecondDownLoad_btnStartDownLoad" android:layout_width="60dp" android:layout_height="40dp" android:textSize="12dp" android:layout_marginLeft="3dp" android:text="開始"/> <Button android:id="@+id/SecondDownLoad_btnStopDownLoad" android:layout_width="60dp" android:layout_height="40dp" android:textSize="12dp" android:text="刪除"/> </LinearLayout> </LinearLayout>
3、SecondDownLoadActivity.java的程式碼如下：
package com.deepreality.myfiledownloader; import android.Manifest; import android.content.Context; import android.content.pm.PackageManager; import android.os.Build; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast; import com.liulishuo.filedownloader.BaseDownloadTask; import com.liulishuo.filedownloader.FileDownloadSampleListener; import com.liulishuo.filedownloader.FileDownloader; import java.io.File; import java.lang.ref.WeakReference; import java.util.regex.Matcher; import java.util.regex.Pattern; public class SecondDownLoadActivity extends AppCompatActivity implements View.OnClickListener { private Context mContext; private Button btnStartDownLoad, btnStopDownLoad; private TextView tvDownLoadFileName, tvDownLoadSpeed, tvDownLoadDetail; private ProgressBar pBar; private String LIULISHUO_APK_URL = "http://cdn.llsapp.com/android/LLS-v4.0-595-20160908-143200.apk"; private String downLoadFileName; private String rootPath = "/mnt/sdcard/TestDownLoadFiles"; private String downLoadFilePath;//下載檔案的儲存路徑（完整路徑，帶有檔名） private String downLoadFileDirectory;//下載檔案的儲存資料夾路徑 private int downLoadId;//分配的下載程序編號 private boolean currentDownLoadState = false; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_test); //判斷android版本號，彈出申請許可權 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { showConfirmAppPermissions(); } FileDownloader.setup(this); bindViews(); bindData(); } @Override protected void onDestroy() { super.onDestroy(); FileDownloader.getImpl().pause(downLoadId); } private void bindViews() { mContext = SecondDownLoadActivity.this; btnStartDownLoad = findViewById(R.id.SecondDownLoad_btnStartDownLoad); btnStopDownLoad = findViewById(R.id.SecondDownLoad_btnStopDownLoad); tvDownLoadFileName = findViewById(R.id.SecondDownLoad_tvDownLoadFileName); tvDownLoadSpeed = findViewById(R.id.SecondDownLoad_tvDownLoadSpeed); tvDownLoadDetail = findViewById(R.id.SecondDownLoad_tvDownLoadDetail); pBar = findViewById(R.id.SecondDownLoad_pBarProgress); btnStartDownLoad.setOnClickListener(this); btnStopDownLoad.setOnClickListener(this); } private void bindData() { pBar.setMax(100); downLoadFileName = regGetFileNameWithoutFileFormat(LIULISHUO_APK_URL, "apk") + ".apk"; tvDownLoadFileName.setText(downLoadFileName); downLoadFilePath = rootPath + File.separator + "1" + File.separator + downLoadFileName; downLoadFileDirectory = rootPath + File.separator + "1"; } @Override public void onClick(View v) { switch (v.getId()) { case R.id.SecondDownLoad_btnStartDownLoad:{ if (!getFileExist(downLoadFilePath)) { currentDownLoadState = !currentDownLoadState; if (currentDownLoadState) { downLoadId = createDownloadTask(1).start(); btnStartDownLoad.setText("暫停"); } else { FileDownloader.getImpl().pause(downLoadId); btnStartDownLoad.setText("開始"); } } else { Toast.makeText(mContext, "當前檔案已存在，請勿重新下載，浪費資源！", Toast.LENGTH_SHORT).show(); } break; } case R.id.SecondDownLoad_btnStopDownLoad:{ new File(downLoadFilePath).delete(); Toast.makeText(mContext, "【" + downLoadFilePath + "】刪除成功", Toast.LENGTH_SHORT).show(); break; } } } //判斷當前檔案是否存在，如存在給出提示，如不存在，開始下載 public boolean getFileExist(String filePath) { File file = new File(filePath); if (file.exists()) { return true; } return false; } //建立下載任務 private BaseDownloadTask createDownloadTask(final int position) { final ViewHolder tag; final String url; boolean isDir = false; String path = ""; switch (position) { case 1: url = LIULISHUO_APK_URL; tag = new ViewHolder(new WeakReference<>(this), pBar, tvDownLoadDetail, tvDownLoadSpeed, position); path = downLoadFilePath; tag.setFilenameTv(tvDownLoadFileName); break; default: tag = null; url = ""; break; } //建立單任務下載 BaseDownloadTask baseDownloadTask = FileDownloader.getImpl().create(url) .setPath(path, isDir) .setCallbackProgressTimes(300) .setMinIntervalUpdateSpeed(400) .setTag(tag) .setListener(new FileDownloadSampleListener() { @Override protected void pending(BaseDownloadTask task, int soFarBytes, int totalBytes) { super.pending(task, soFarBytes, totalBytes); ((ViewHolder) task.getTag()).updatePending(task); } @Override protected void progress(BaseDownloadTask task, int soFarBytes, int totalBytes) { super.progress(task, soFarBytes, totalBytes); ((ViewHolder) task.getTag()).updateProgress(soFarBytes, totalBytes, task.getSpeed()); } @Override protected void error(BaseDownloadTask task, Throwable e) { super.error(task, e); ((ViewHolder) task.getTag()).updateError(e, task.getSpeed()); } @Override protected void connected(BaseDownloadTask task, String etag, boolean isContinue, int soFarBytes, int totalBytes) { super.connected(task, etag, isContinue, soFarBytes, totalBytes); ((ViewHolder) task.getTag()).updateConnected(etag, task.getFilename()); } @Override protected void paused(BaseDownloadTask task, int soFarBytes, int totalBytes) { super.paused(task, soFarBytes, totalBytes); ((ViewHolder) task.getTag()).updatePaused(task.getSpeed()); } @Override protected void completed(BaseDownloadTask task) { super.completed(task); ((ViewHolder) task.getTag()).updateCompleted(task); } @Override protected void warn(BaseDownloadTask task) { super.warn(task); ((ViewHolder) task.getTag()).updateWarn(); } }); return baseDownloadTask; } private class ViewHolder { private ProgressBar pb; private TextView detailTv; private TextView speedTv; private int position; private TextView filenameTv; private WeakReference<SecondDownLoadActivity> weakReferenceContext; public ViewHolder(WeakReference<SecondDownLoadActivity> weakReferenceContext, final ProgressBar pb, final TextView detailTv, final TextView speedTv, final int position) { this.weakReferenceContext = weakReferenceContext; this.pb = pb; this.detailTv = detailTv; this.position = position; this.speedTv = speedTv; } //設定檔名 public void setFilenameTv(TextView filenameTv) { this.filenameTv = filenameTv; } //更新下載速度 private void updateSpeed(int speed) { speedTv.setText(String.format("%dKB/s", speed)); } //更新進度條 public void updateProgress(final int sofar, final int total, final int speed) { if (total == -1) { // chunked transfer encoding data pb.setIndeterminate(true); } else { pb.setMax(total); pb.setProgress(sofar); } updateSpeed(speed); if (detailTv != null) { detailTv.setText(String.format("【sofar: %dM total: %dM】", convertFileSize(sofar), convertFileSize(total))); } } public int convertFileSize(int size) { size = size / 1024 / 1024; return size; } //更新Pending時的UI（等待） public void updatePending(BaseDownloadTask task) { if (filenameTv != null) { filenameTv.setText(task.getFilename()); } } //更新Pause時的UI（暫停） public void updatePaused(final int speed) { //toast(String.format("paused %d", position)); updateSpeed(speed); pb.setIndeterminate(false); } //更新連線時的UI public void updateConnected(String etag, String filename) { if (filenameTv != null) { filenameTv.setText(filename); } } //更新出現警告時的UI public void updateWarn() { //toast(String.format("warn %d", position)); pb.setIndeterminate(false); } //更新出現錯誤時的UI public void updateError(final Throwable ex, final int speed) { //toast(String.format("error %d %s", position, ex)); updateSpeed(speed); pb.setIndeterminate(false); ex.printStackTrace(); } //更新下載完成時的UI public void updateCompleted(final BaseDownloadTask task) { toast(String.format("下載完成！儲存路徑為：【%s】", task.getTargetFilePath())); if (detailTv != null) { detailTv.setText(String.format("【sofar: %dM total: %dM】", convertFileSize(task.getSmallFileSoFarBytes()), convertFileSize(task.getSmallFileTotalBytes()))); } updateSpeed(task.getSpeed()); pb.setIndeterminate(false); pb.setMax(task.getSmallFileTotalBytes()); pb.setProgress(task.getSmallFileSoFarBytes()); } } public void toast(final String msg) { Toast.makeText(mContext, msg, Toast.LENGTH_SHORT).show(); } // 正則檢測url包含指定格式並獲取檔名(不帶檔案格式字尾) public static String regGetFileNameWithoutFileFormat(String fileName, String fileFormat) { Pattern pat = Pattern.compile("(.android/)(.+?)(\\.)(" + fileFormat + ")"); Matcher m = pat.matcher(fileName); if(m.find()){ return m.group(2); } return null; } // 7.0動態申請許可權 public void showConfirmAppPermissions() { if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) { } else { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE}, 1); } } } }至此，單任務下載完成，這個很簡單，記錄一下。主要是多工下載這塊，繼續研究一下。