Android打开特定文件，例如自动安装APK程序

public static Intent openFile(String filePath){

  File file = new File(filePath);
  if(!file.exists()) return null;
  /* 取得扩展名 */
  String end=file.getName().substring(file.getName().lastIndexOf(".") + 1,file.getName().length()).toLowerCase(); 
  /* 依扩展名的类型决定MimeType */
  if(end.equals("m4a")||end.equals("mp3")||end.equals("mid")||
    end.equals("xmf")||end.equals("ogg")||end.equals("wav")){
   return getAudioFileIntent(filePath);
  }else if(end.equals("3gp")||end.equals("mp4")){
   return getAudioFileIntent(filePath);
  }else if(end.equals("jpg")||end.equals("gif")||end.equals("png")||
    end.equals("jpeg")||end.equals("bmp")){
   return getImageFileIntent(filePath);
  }else if(end.equals("apk")){
   return getApkFileIntent(filePath);
  }else if(end.equals("ppt")){
   return getPptFileIntent(filePath);
  }else if(end.equals("xls")){
   return getExcelFileIntent(filePath);
  }else if(end.equals("doc")){
   return getWordFileIntent(filePath);
  }else if(end.equals("pdf")){
   return getPdfFileIntent(filePath);
  }else if(end.equals("chm")){
   return getChmFileIntent(filePath);
  }else if(end.equals("txt")){
   return getTextFileIntent(filePath,false);
  }else{
   return getAllIntent(filePath);
  }
 }
 
 //Android获取一个用于打开APK文件的intent
 public static Intent getAllIntent( String param ) {

  Intent intent = new Intent();  
  intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
  intent.setAction(android.content.Intent.ACTION_VIEW);  
  Uri uri = Uri.fromFile(new File(param ));
  intent.setDataAndType(uri,"*/*"); 
  return intent;
 }
 //Android获取一个用于打开APK文件的intent
 public static Intent getApkFileIntent( String param ) {

  Intent intent = new Intent();  
  intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
  intent.setAction(android.content.Intent.ACTION_VIEW);  
  Uri uri = Uri.fromFile(new File(param ));
  intent.setDataAndType(uri,"application/vnd.android.package-archive"); 
  return intent;
 }

 //Android获取一个用于打开VIDEO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AUDIO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;   
 }  

 //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;   
 }

原文出处：http://blog.csdn.net/weich_java/article/details/7002829