andriod 播放mp4

权限
  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

activity_main.xml //gisoracle 版权所有

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <EditText
            android:id="@+id/et_path"
            android:layout_width="500px"
            android:layout_height="wrap_content"
            android:text="/sdcard/a.mp4" />

        <Button
            android:id="@+id/btn_browse"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="浏览" />
    </LinearLayout>


    <SeekBar
        android:id="@+id/seekBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />



    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_play"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="播放" />

        <Button
            android:id="@+id/btn_pause"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="暂停" />

        <Button
            android:id="@+id/btn_replay"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="重播" />

        <Button
            android:id="@+id/btn_stop"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="停止" />
        <TextView
            android:id="@+id/textView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="时间:" />
    </LinearLayout>

    <VideoView
        android:id="@+id/vv_videoview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</LinearLayout>

 java //gisoracle 版权所有

package com.example.yanlei.myapplication;

import android.media.MediaMetadataRetriever;
import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.VideoView;
import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.Toast;
import android.widget.VideoView;
import android.widget.SeekBar.OnSeekBarChangeListener;

import java.io.File;
import java.util.HashMap;

import android.os.Handler;

public class MainActivity extends AppCompatActivity {

    private final String TAG = "main";
    private EditText et_path;
    private Button btn_play, btn_pause, btn_replay, btn_stop, btn_browse;
    private SeekBar seekBar;
    private VideoView vv_video;
    private boolean isPlaying;
    private TextView pTextView = null;
    private Handler handler = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        seekBar = (SeekBar) findViewById(R.id.seekBar);
        et_path = (EditText) findViewById(R.id.et_path);
        vv_video = (VideoView) findViewById(R.id.vv_videoview);
        pTextView = (TextView) findViewById(R.id.textView);

        btn_play = (Button) findViewById(R.id.btn_play);
        btn_pause = (Button) findViewById(R.id.btn_pause);
        btn_replay = (Button) findViewById(R.id.btn_replay);
        btn_stop = (Button) findViewById(R.id.btn_stop);
        btn_browse = (Button) findViewById(R.id.btn_browse);

        btn_play.setOnClickListener(click);
        btn_pause.setOnClickListener(click);
        btn_replay.setOnClickListener(click);
        btn_stop.setOnClickListener(click);
        btn_browse.setOnClickListener(click);

        // 为进度条添加进度更改事件
        seekBar.setOnSeekBarChangeListener(change);

        //创建属于主线程的handler
        handler = new Handler();

    }

    private OnSeekBarChangeListener change = new OnSeekBarChangeListener() {

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // 当进度条停止修改的时候触发
            // 取得当前进度条的刻度
            int progress = seekBar.getProgress();
            if (vv_video != null && vv_video.isPlaying()) {
                // 设置当前播放的位置
                vv_video.seekTo(progress);
            }
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress,
                                      boolean fromUser) {

        }
    };
    private View.OnClickListener click = new View.OnClickListener() {

        @Override
        public void onClick(View v) {

            switch (v.getId()) {
                case R.id.btn_play:
                    play(0);
                    break;
                case R.id.btn_pause:
                    pause();
                    break;
                case R.id.btn_replay:
                    replay();
                    break;
                case R.id.btn_stop:
                    stop();
                    break;
                case R.id.btn_browse:
                    browse();
                    break;
                default:
                    break;
            }
        }
    };

    //获得MP4时长
    private int getTimeLong(String videoPath) {


        MediaMetadataRetriever retr = new MediaMetadataRetriever();
        retr.setDataSource(videoPath);
        //String height = retr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT); // 视频高度
        //String width = retr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH); // 视频宽度
        //String rotation = retr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION); // 视频旋转方向
        String timelong = retr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);//时长，单位为毫秒
        retr.release();
        int l = Integer.parseInt(timelong);
        return l;

    }

    String myText = "";

    protected void play(int msec) {
        Log.i(TAG, " 获取视频文件地址");
        String path = et_path.getText().toString().trim();
        File file = new File(path);
        if (!file.exists()) {
            Toast.makeText(this, "视频文件路径错误", 0).show();
            return;
        }

        Log.i(TAG, "指定视频源路径");
        vv_video.setVideoPath(file.getAbsolutePath());
        Log.i(TAG, "开始播放");
        vv_video.start();

        // 按照初始位置播放
        vv_video.seekTo(msec);
        // 设置进度条的最大进度为视频流的最大播放时长
        final int time = getTimeLong(file.getAbsolutePath()) / 100;
        seekBar.setMax(time);
        Toast.makeText(this, "长度:" + time, Toast.LENGTH_LONG).show();
        // 开始线程，更新进度条的刻度
        new Thread() {

            @Override
            public void run() {
                try {
                    isPlaying = true;
                    while (isPlaying) {
                        // 如果正在播放，0.1.毫秒更新一次进度条
                        final int current = vv_video.getCurrentPosition() / 100;
                        seekBar.setProgress(current);
                     /*   try {
                            myText = "总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒";
                            // pTextView.setText("总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒");
                            new WorkThread().start();
                        } catch (Exception ex) {

                            Log.d("错误:", ex.getMessage().toString());
                        }*/

                        new Thread() {
                            public void run() {
                                myText = "总时间：" + time / 10 + "秒,目前：" + current / 10 + "秒";
                                handler.post(updateUIRunnable);
                            }
                        }.start();

                        //Toast.makeText(this, "当前:"+current,Toast.LENGTH_LONG).show();
                        sleep(100);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }.start();
        // 播放之后设置播放按钮不可用
        btn_play.setEnabled(false);

        vv_video.setOnCompletionListener(new OnCompletionListener() {

            @Override
            public void onCompletion(MediaPlayer mp) {
                // 在播放完毕被回调
                btn_play.setEnabled(true);
            }
        });

        vv_video.setOnErrorListener(new OnErrorListener() {

            @Override
            public boolean onError(MediaPlayer mp, int what, int extra) {
                // 发生错误重新播放
                play(0);
                isPlaying = false;
                return false;
            }
        });
    }



    // 构建Runnable对象，并在runnable中更新UI
    Runnable updateUIRunnable = new Runnable() {
        @Override
        public void run() {
            try {

                pTextView.setText(myText);
            } catch (Exception ex) {
                Log.e("严重错误:", ex.getMessage().toString());

            }
        }
    };

    /**
     * 重新开始播放
     */
    protected void replay() {
        if (vv_video != null && vv_video.isPlaying()) {
            vv_video.seekTo(0);
            Toast.makeText(this, "重新播放", 0).show();
            btn_pause.setText("暂停");
            return;
        }
        isPlaying = false;
        play(0);

    }

    protected void browse() {
        Intent it = new Intent(Intent.ACTION_GET_CONTENT);    //创建动作为 "选取" 的 Intent
        it.setType("video/*");     //要选取所有视频类型
        startActivityForResult(it, 101);

    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == Activity.RESULT_OK) {

            Uri uri = convertUri(data.getData());  //获取选取文件的 Uri 并进行 Uri 格式转换
            et_path.setText(uri.getPath());  //显示文件名 (Uri 最后的节点文字)
            // txvUri.setText("文件位置：" + uri.getPath());//显示文件的路径
        }
    }

    Uri convertUri(Uri uri) { //将 "content://" 类型的 Uri 转换为 "file://" 的 Uri
        if (uri.toString().substring(0, 7).equals("content")) {  //如果是以 "content" 开头
            String[] colName = {MediaStore.MediaColumns.DATA};    //声明要查询的字段
            Cursor cursor = getContentResolver().query(uri, colName,  //以 uri 进行查询
                    null, null, null);
            cursor.moveToFirst();      //移到查询结果的第一个记录
            uri = Uri.parse("file://" + cursor.getString(0)); //将路径转为 Uri
            cursor.close();     //关闭查询结果
        }
        return uri;   //返回 Uri 对象
    }

    /**
     * 暂停或继续
     */
    protected void pause() {
        if (btn_pause.getText().toString().trim().equals("继续")) {
            btn_pause.setText("暂停");
            vv_video.start();
            Toast.makeText(this, "继续播放", 0).show();
            return;
        }
        if (vv_video != null && vv_video.isPlaying()) {
            vv_video.pause();
            btn_pause.setText("继续");
            Toast.makeText(this, "暂停播放", 0).show();
        }
    }

    /*
     * 停止播放
     */
    protected void stop() {
        if (vv_video != null && vv_video.isPlaying()) {
            vv_video.stopPlayback();
            btn_play.setEnabled(true);
            isPlaying = false;
        }
    }
}