WebView下载文件并显示进度

概述1.activitypackagecom.sam.more.activitys.webview;importandroid.content.Context;importandroid.os.Bundle;importandroid.os.Handler;importandroid.os.Message;importandroid.support.v7.app.AppCompatActivity;importandroid.view.View;importandroid.w

1.activity

package com.sam.more.activitys.webvIEw;import androID.content.Context;import androID.os.Bundle;import androID.os.Handler;import androID.os.Message;import androID.support.v7.app.AppCompatActivity;import androID.vIEw.VIEw;import androID.webkit.DownloadListener;import androID.webkit.WebVIEw;import androID.webkit.WebVIEwClIEnt;import androID.Widget.button;import androID.Widget.EditText;import com.sam.more.R;import butterknife.BindVIEw;import butterknife.ButterKnife;import butterknife.OnClick;public class WebVIEwDownloadActivity extends AppCompatActivity implements DownloadCallback {    @BindVIEw(R.ID.webv_download)    WebVIEw webvDownload;    @BindVIEw(R.ID.et_url)    EditText etUrl;    @BindVIEw(R.ID.btn_download)    button btnDownload;    Context context;    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_web_vIEw_download);        ButterKnife.bind(this);        context = this;        initVIEw();    }    private voID initVIEw() {        webvDownload.setWebVIEwClIEnt(new WebVIEwClIEnt() {            @OverrIDe            public boolean shouldOverrIDeUrlLoading(WebVIEw vIEw, String url) {                vIEw.loadUrl(url);                return true;            }        });        webvDownload.setDownloadListener(new DownloadListener() {            @OverrIDe            public voID onDownloadStart(String url, String userAgent, String contentdisposition, String mimetype, long contentLength) {                new Thread(new DownLoadThread(url, WebVIEwDownloadActivity.this)).start();            }        });    }    @OnClick({R.ID.btn_download})    public voID onClick(VIEw vIEw) {        switch (vIEw.getID()) {            case R.ID.btn_download:                webvDownload.loadUrl(etUrl.getText().toString().trim());                break;        }    }    @OverrIDe    public voID percentage(final String percentage) {        Message message = new Message();        message.obj = percentage;        mHandler.sendMessage(message);    }    private Handler mHandler = new Handler(new Handler.Callback() {        @OverrIDe        public boolean handleMessage(Message message) {            if (message.obj.toString().equals("100%")) {                btnDownload.setText("下载完成");                mHandler.removeCallbacksAndMessages(null);                return false;            }            btnDownload.setText(message.obj.toString());            return true;        }    });}

2.layout

<?xml version="1.0" enCoding="utf-8"?><linearLayout xmlns:androID="http://schemas.androID.com/apk/res/androID"    xmlns:tools="http://schemas.androID.com/tools"    androID:layout_wIDth="match_parent"    androID:layout_height="match_parent"    androID:orIEntation="vertical"    tools:context=".activitys.webvIEw.WebVIEwDownloadActivity">    <EditText        androID:ID="@+ID/et_url"        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:text="http://csdn-app.csdn.net/csdn.apk" />    <button        androID:ID="@+ID/btn_download"        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"        androID:text="下载" />    <WebVIEw        androID:ID="@+ID/webv_download"        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content" /></linearLayout>

3.thread

package com.sam.more.activitys.webvIEw;import androID.os.Environment;import androID.util.Log;import java.io.file;import java.io.fileOutputStream;import java.io.IOException;import java.io.inputStream;import java.net.httpURLConnection;import java.net.URL;import java.text.DecimalFormat;/** * Author: Sam * Date: 2021-03-13 11:32 * Description: */public class DownLoadThread implements Runnable {    private String dlUrl;    private DownloadCallback callback;    DownLoadThread(String dlUrl, DownloadCallback callback) {        this.dlUrl = dlUrl;        this.callback = callback;    }    @OverrIDe    public voID run() {        inputStream in = null;        fileOutputStream fout = null;        int contentLength, downedfileLength = 0;//文件总大小，已下载大小        DecimalFormat df = new DecimalFormat("0%");        try {            URL httpUrl = new URL(dlUrl);            httpURLConnection conn = (httpURLConnection) httpUrl.openConnection();            contentLength = conn.getContentLength();            Log.e("文件总大小", contentLength + "");            in = conn.getinputStream();            file downloadfile, sdfile;            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {                Log.e("sam", "SD卡可写");                downloadfile = Environment.getExternalStorageDirectory();                sdfile = new file(downloadfile, "csdn_clIEnt.apk");                fout = new fileOutputStream(sdfile);            } else {                Log.e("sam", "SD卡不存在或者不可读写");            }            byte[] buffer = new byte[1024];            int len;            while ((len = in.read(buffer)) != -1) {                if (fout != null) {                    fout.write(buffer, 0, len);                    downedfileLength += len;                    callback.percentage(df.format((float) downedfileLength / contentLength));                }            }        } catch (Exception e) {            e.printstacktrace();        } finally {            if (in != null) {                try {                    in.close();                } catch (IOException e) {                    e.printstacktrace();                }            }            if (fout != null) {                try {                    fout.close();                } catch (IOException e) {                    e.printstacktrace();                }            }        }    }}

4.callback

package com.sam.more.activitys.webvIEw;/** * Author: Sam * Date: 2021-03-13 13:22 * Description: */public interface DownloadCallback {    voID percentage(String percentage);}

到这就已经OK啦，如果对您有一点点帮助，还请给个赞，谢谢！

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