CallingBed2/app/src/main/java/com/wdkl/callingbed2/util/DownloadUtil2.java

package com.wdkl.callingbed2.util;

import android.support.annotation.NonNull;

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

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class DownloadUtil2 {
    private static final String TAG = "DownloadUtil2";
    private static DownloadUtil2 downloadUtil2;
    private final OkHttpClient okHttpClient;

    private DownloadUtil2() {
        okHttpClient = new OkHttpClient();
    }

    public static DownloadUtil2 getInstance() {
        if (downloadUtil2 == null) {
            synchronized (DownloadUtil.class) {
                if (downloadUtil2 == null) {
                    downloadUtil2 = new DownloadUtil2();
                }
            }
        }
        return downloadUtil2;
    }

    /**
     * @param url      下载连接
     * @param listener 下载监听
     */
    public void download(final String url,final String dir, final String name, boolean redownload, final OnDownloadListener listener) {
        if (!redownload) {
            File file = new File(dir + "/" + name);
            if (file.exists()) {
                LogUtil.d(TAG, "file exist==" + file.getPath());
                if (listener != null) {
                    listener.onDownloadSuccess(); // 下载完成
                }
                return;
            }
        }

        final String fileDir = isHaveExistDir(new File(dir), new File(dir + "/" + name));
        LogUtil.d(TAG, "url==" + url + ", fileDir==" + fileDir);
        if (fileDir == null) {
            ToastUtil.showToast("下载文件路径创建失败");
            if (listener != null) {
                listener.onDownloadFailed(); // 下载失败
            }
            return;
        }
        Request request = new Request.Builder().url(url).build();
        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                LogUtil.d(TAG, "onFailure==" + e.toString());
                if (listener != null) {
                    listener.onDownloadFailed(); // 下载失败
                }
            }

            @Override
            public void onResponse(Call call, Response response) {
                LogUtil.d(TAG, "response==" + response.body().contentLength());
                InputStream is = null;
                byte[] buf = new byte[2048];
                int len;
                FileOutputStream fos = null;
                try {
                    is = response.body().byteStream();
                    long total = response.body().contentLength();
                    File file = new File(fileDir, name);
                    fos = new FileOutputStream(file);
                    long sum = 0;
                    while ((len = is.read(buf)) != -1) {
                        fos.write(buf, 0, len);
                        sum = sum + (long) len;
                        //int progress = (int) (sum * 1.0f / total * 100);
                        float sp = (float) sum / (float) total;
                        int progress = (int) (sp * 100);
                        //LogUtil.d(TAG, "progress==" + progress);
                        if (listener != null) {
                            listener.onDownloading(progress);// 下载中
                        }
                    }
                    fos.flush();
                    if (listener != null) {
                        listener.onDownloadSuccess(); // 下载完成
                    }
                } catch (Exception e) {
                    LogUtil.d(TAG, "Exception==");
                    if (listener != null) {
                        listener.onDownloadFailed();
                    }
                } finally {
                    try {
                        if (is != null)
                            is.close();
                        if (fos != null)
                            fos.close();
                    } catch (IOException e) {
                        LogUtil.d(TAG, "IOException==");
                    }
                }
            }
        });
    }


    private String isHaveExistDir(File dir, File file) {
        try {
            if (!dir.mkdirs()) {
                dir.createNewFile();
            }
            deleteFile(file);//只要文件名相同就可以自动替换(按道理此处不需要了，但为了保险起见还是先执行删除操作)。
            return dir.getAbsolutePath();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public boolean deleteFile(File downloadFile) {
        //if (!downloadFile.isDirectory()) throw new NotHaveThisFileException();
        return downloadFile.delete();
    }

    /**
     * @param url
     * @return 从下载连接中解析出文件名
     */
    @NonNull
    private String getNameFromUrl(String url) {
        return url.substring(url.lastIndexOf("/") + 1);
    }

    public interface OnDownloadListener {
        /**
         * 下载成功
         */
        void onDownloadSuccess();

        /**
         * @param progress 下载进度
         */
        void onDownloading(int progress);

        /**
         * 下载失败
         */
        void onDownloadFailed();
    }
}