Android用于打开各种文件的intent

import android.app.Activity;    import android.content.Intent;    import android.net.Uri;    import android.net.Uri.Builder;    import java.io.File;    import android.content.Intent;    //自定义android Intent类，    //可用于获取打开以下文件的intent    //PDF,PPT,WORD,EXCEL,CHM,HTML,TEXT,AUDIO,VIDEO    示例:    //这个不行，可能是因为PDF.apk程序没有权限访问其它APK里的asset资源文件,又或者是路径写错?    //Intent it = getPdfFileIntent("file:///android_asset/helphelp.pdf");    //下面这些都OK    //Intent it = getHtmlFileIntent("/mnt/sdcard/tutorial.html");//SD卡主目录    //Intent it = getHtmlFileIntent("/sdcard/tutorial.html");//SD卡主目录,这样也可以    Intent it = getHtmlFileIntent("/system/etc/tutorial.html");//系统内部的etc目录    //Intent it = getPdfFileIntent("/system/etc/helphelp.pdf");    //Intent it = getWordFileIntent("/system/etc/help.doc");    //Intent it = getExcelFileIntent("/mnt/sdcard/Book1.xls")    //Intent it = getPptFileIntent("/mnt/sdcard/download/Android_PPT.ppt");//SD卡的download目录下    //Intent it = getVideoFileIntent("/mnt/sdcard/ice.avi");    //Intent it = getAudioFileIntent("/mnt/sdcard/ren.mp3");    //Intent it = getImageFileIntent("/mnt/sdcard/images/001041580.jpg");    //Intent it = getTextFileIntent("/mnt/sdcard/hello.txt",false);    startActivity( it );    public class MyIntent    {     //android获取一个用于打开HTML文件的intent      public static Intent getHtmlFileIntent( String param )      {        Uri uri = Uri.parse(param ).buildUpon().encodedAuthority("com.android.htmlfileprovider").scheme("content").encodedPath(param ).build();        Intent intent = new Intent("android.intent.action.VIEW");        intent.setDataAndType(uri, "text/html");        return intent;      }     //android获取一个用于打开图片文件的intent      public static Intent getImageFileIntent( String param )      {        Intent intent = new Intent("android.intent.action.VIEW");        intent.addCategory("android.intent.category.DEFAULT");        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        Uri uri = Uri.fromFile(new File(param ));        intent.setDataAndType(uri, "image/*");        return intent;      }      //android获取一个用于打开PDF文件的intent      public static Intent getPdfFileIntent( String param )      {        Intent intent = new Intent("android.intent.action.VIEW");        intent.addCategory("android.intent.category.DEFAULT");        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        Uri uri = Uri.fromFile(new File(param ));        intent.setDataAndType(uri, "application/pdf");        return intent;      }     //android获取一个用于打开文本文件的intent     public static Intent getTextFileIntent( String param, boolean paramBoolean)     {     Intent intent = new Intent("android.intent.action.VIEW");      intent.addCategory("android.intent.category.DEFAULT");     intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);     if (paramBoolean)     {    Uri uri1 = Uri.parse(param );     intent.setDataAndType(uri1, "text/plain");     }     else     {    Uri uri2 = Uri.fromFile(new File(param ));    intent.setDataAndType(uri2, "text/plain");     }     return intent;    }     //android获取一个用于打开音频文件的intent      public static Intent getAudioFileIntent( String param )      {        Intent intent = new Intent("android.intent.action.VIEW");        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);      intent.putExtra("oneshot", 0);        intent.putExtra("configchange", 0);        Uri uri = Uri.fromFile(new File(param ));        intent.setDataAndType(uri, "audio/*");        return intent;      }      //android获取一个用于打开视频文件的intent      public static Intent getVideoFileIntent( String param )      {         Intent intent = new Intent("android.intent.action.VIEW");        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);        intent.putExtra("oneshot", 0);        intent.putExtra("configchange", 0);        Uri uri = Uri.fromFile(new File(param ));        intent.setDataAndType(uri, "video/*");        return intent;      }      //android获取一个用于打开CHM文件的intent      public static Intent getChmFileIntent( String param )      {         Intent intent = new Intent("android.intent.action.VIEW");        intent.addCategory("android.intent.category.DEFAULT");        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        Uri uri = Uri.fromFile(new File(param ));        intent.setDataAndType(uri, "application/x-chm");        return intent;      }     //android获取一个用于打开Word文件的intent       public static Intent getWordFileIntent( String param )      {         Intent intent = new Intent("android.intent.action.VIEW");         intent.addCategory("android.intent.category.DEFAULT");         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);         Uri uri = Uri.fromFile(new File(param ));         intent.setDataAndType(uri, "application/msword");         return intent;       }     //android获取一个用于打开Excel文件的intent       public static Intent getExcelFileIntent( String param )       {         Intent intent = new Intent("android.intent.action.VIEW");         intent.addCategory("android.intent.category.DEFAULT");         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);         Uri uri = Uri.fromFile(new File(param ));         intent.setDataAndType(uri, "application/vnd.ms-excel");         return intent;       }     //android获取一个用于打开PPT文件的intent       public static Intent getPptFileIntent( String param )       {         Intent intent = new Intent("android.intent.action.VIEW");         intent.addCategory("android.intent.category.DEFAULT");         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);         Uri uri = Uri.fromFile(new File(param ));         intent.setDataAndType(uri, "application/vnd.ms-powerpoint");         return intent;       }    }