DownloadManager.java

package com.minstone.mdoctor.tool.net;

import android.os.Handler;
import android.os.Looper;

import com.minstone.util.LogUtil;
import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import
 
 com.squareup.okhttp.Response;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;

import static com.minstone.util.FileAccessor.getFileName;

/**
 * Created by LITP on 2016/9/26.
 */
 


public class DownloadManager {


    public DownloadManager() {
        mDelivery = new Handler(Looper.getMainLooper());
    }

    private Handler mDelivery;     //主執行緒返回

    private Call downCall;         //下載的call

    private static OkHttpClient mOkHttpClient;

    private static DownloadManager mInstance;    //單例
 


    public static DownloadManager getInstance() {
        if (mInstance == null) {
            synchronized (OkHttpManager.class) {
                if (mInstance == null) {
                    mInstance = new DownloadManager();
                }
            }
        }
        return mInstance;
    }



    //synchronized修飾的靜態方法鎖定的是這個類的所有物件,保證在同一時刻最多隻有一個執行緒執行該段程式碼
    public synchronized  OkHttpClient getOkHttpClient() {
        if (null == mOkHttpClient) {
            try {
                mOkHttpClient = newOkHttpClient();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return mOkHttpClient;
    }

    /**
     * 建立okhttp
     *
     * @return
     * @throws Exception
     */
    private OkHttpClient newOkHttpClient() throws Exception {

        //建立okHttpClient物件
        OkHttpClient mOkHttpClient = new OkHttpClient();

        TrustManager tm = new OkHttpManager.myTrustManager();
        SSLContext sslContext = SSLContext.getInstance("TLS");
        sslContext.init(null, new TrustManager[]{tm}, null);

        mOkHttpClient.setSslSocketFactory(sslContext.getSocketFactory());


        return mOkHttpClient;
    }


    /**
     * 非同步下載檔案
     *
     * @param url         檔案的下載地址
     * @param destFileDir 本地檔案儲存的資料夾
     * @param callback
     */
    private void okHttpDownload(final String url, final String destFileDir, final ResultCallback callback) {

        final Request request = new Request.Builder()
                .url(url)
                .build();

        downCall = getOkHttpClient().newCall(request);
        downCall.enqueue(new Callback() {
            @Override
            public void onFailure(final Request request, final IOException e) {
                sendFailedStringCallback(request, e, callback);
            }

            @Override
            public void onResponse(Response response) {
                InputStream is = null;
                byte[] buf = new byte[2048];
                int len = 0;
                FileOutputStream fos = null;
                try {
                    double current = 0;
                    double total = response.body().contentLength();

                    is = response.body().byteStream();
                    File file = new File(destFileDir, getFileName(url));
                    fos = new FileOutputStream(file);
                    while ((len = is.read(buf)) != -1) {
                        current += len;
                        fos.write(buf, 0, len);
                        LogUtil.w("download current------>" + current);
                        sendProgressCallBack(total, current, callback);
                    }
                    fos.flush();
                    //如果下載檔案成功，第一個引數為檔案的絕對路徑
                    sendSuccessResultCallback(file.getAbsolutePath(), callback);
                } catch (IOException e) {
                    sendFailedStringCallback(response.request(), e, callback);
                } finally {
                    try {
                        if (is != null) is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    try {
                        if (fos != null) fos.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

            }
        });
    }

    //下載失敗ui執行緒回撥
    private void sendFailedStringCallback(final Request request, final Exception e, final ResultCallback callback) {
        mDelivery.post(new Runnable() {
            @Override
            public void run() {
                if (callback != null)
                    callback.onError(request, e);
            }
        });
    }

    //下載成功ui執行緒回撥
    private void sendSuccessResultCallback(final Object object, final ResultCallback callback) {
        mDelivery.post(new Runnable() {
            @Override
            public void run() {
                if (callback != null) {
                    callback.onResponse(object);
                }
            }
        });
    }


    //下載回撥介面
    public static abstract class ResultCallback<T> {

        //下載錯誤
        public abstract void onError(Request request, Exception e);

        //下載成功
        public abstract void onResponse(T response);

        //下載進度
        public abstract void onProgress(double total, double current);
    }


    /**
     * 進度資訊ui執行緒回撥
     *
     * @param total    總計大小
     * @param current  當前進度
     * @param callBack
     * @param <T>
     */
    private <T> void sendProgressCallBack(final double total, final double current, final ResultCallback<T> callBack) {
        mDelivery.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    callBack.onProgress(total, current);
                }
            }
        });
    }


    /*  下面為對外開放介面 */




    /**
     * 下載檔案
     *
     * @param url 檔案連結
     * @param destDir 下載儲存地址
     * @param callback 回撥
     */
    public static void downloadFile(String url, String destDir, ResultCallback callback) {
        getInstance().okHttpDownload(url, destDir, callback);
    }


    /**
     * 取消下載
     */
    public static void cancleDown(){
        getInstance().downCall.cancel();
    }





}

使用:

    private void startDown(){
        String apkUrl = "apk下載的連結";
        String fileUrl = Environment.getExternalStorageDirectory().getAbsolutePath();
        DownloadManager.downloadFile(apkUrl,fileUrl,new DownloadCallBack());
    }


    //監聽類
    class DownloadCallBack extends DownloadManager.ResultCallback {

        @Override
        public void onError(Request request, Exception e) {
            //下載失敗返回
        }

        @Override
        public void onResponse(Object response) {
            //下載成功返回
        }

        @Override
        public void onProgress(double total, double current) {
            //進度返回
        }
    }