安卓下载工具类

安卓学习记 之下载工具类

package com.android.utils;

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;

/**
 * Created by 前朝不良帅 on 2020/3/10.
 */

public class DownloadUtil {
    
    
    private static DownloadUtil downloadUtil;
    private final OkHttpClient okHttpClient;

    public static DownloadUtil get() {
    
    
        if (downloadUtil == null) {
    
    
            downloadUtil = new DownloadUtil();
        }
        return downloadUtil;
    }

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

    /**
     * @param url          下载连接
     * @param destFileDir  下载的文件储存目录
     * @param destFileName 下载文件名称
     * @param listener     下载监听
     */
    public void download(final String url, final String destFileDir, final String destFileName, final OnDownloadListener listener) {
    
    
        Request request = new Request.Builder().url(url).build();
        okHttpClient.newCall(request).enqueue(new Callback() {
    
    
            @Override
            public void onFailure(Call call, IOException e) {
    
    
                // 下载失败监听回调
                listener.onDownloadFailed(e);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
    
    
                InputStream is = null;
                byte[] buf = new byte[2048];
                int len = 0;
                FileOutputStream fos = null;
                // 储存下载文件的目录
                File dir = new File(destFileDir);
                if (!dir.exists()) {
    
    
                    dir.mkdirs();
                }
                File file = new File(dir, destFileName);
                try {
    
    
                    is = response.body().byteStream();
                    long total = response.body().contentLength();
                    fos = new FileOutputStream(file);
                    long sum = 0;
                    while ((len = is.read(buf)) != -1) {
    
    
                        fos.write(buf, 0, len);
                        sum += len;
                        int progress = (int) (sum * 1.0f / total * 100);
                        // 下载中更新进度条
                        listener.onDownloading(progress);
                    }
                    fos.flush();
                    // 下载完成
                    listener.onDownloadSuccess(file);
                } catch (Exception e) {
    
    
                    listener.onDownloadFailed(e);
                } finally {
    
    
                    try {
    
    
                        if (is != null)
                            is.close();
                    } catch (IOException e) {
    
    
                    }
                    try {
    
    
                        if (fos != null)
                            fos.close();
                    } catch (IOException e) {
    
    
                    }
                }
            }
        });
    }

    public interface OnDownloadListener {
    
    
        /**
         * @param file 下载成功后的文件
         */
        void onDownloadSuccess(File file);

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

        /**
         * @param e 下载异常信息
         */
        void onDownloadFailed(Exception e);
    }


}




/*

配置信息
需要okhttp3
implementation("com.squareup.okhttp3:okhttp:3.14.1")
*/

/*
调用方法

DownloadUtil.get().download(lyricPath, getCacheDir().toString(), fileName, new DownloadUtil.OnDownloadListener() {
                    @Override
                    public void onDownloadSuccess(File file) {//下载成功
                        List<Lrc> lrcs = LrcHelper.parseLrcFromFile(file);
                        mLrcView.setLrcData(lrcs);
                    }

                    @Override
                    public void onDownloading(int progress) {//下载进度

                    }

                    @Override
                    public void onDownloadFailed(Exception e) {//下载异常

                    }
                });
                
   */