Android獲取檔案的mimeType的封裝
阿新 • • 發佈：2019-01-01
概述
MIME(Multipurpose Internet Mail Extensions)多用途網際網路郵件擴充套件型別。是設定某種副檔名的檔案用一種應用程式來開啟的方式型別，當該副檔名檔案被訪問的時候，瀏覽器會自動使用指定應用程式來開啟。多用於指定一些客戶端自定義的檔名，以及一些媒體檔案開啟方式。
步驟
- 1.定義各種檔案對應的mimeType的xml檔案
在res目錄下面建立一個xml資料夾,在此資料夾下面建立對應xml檔案
<?xml version="1.0" encoding="utf-8"?>
<MimeTypes> - 2.程式碼實現
可直接copy使用,詳情請看註釋
package com.geely.mars.sqldemo.tools;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.XmlResourceParser;
import android.text.TextUtils;
import com.geely.mars.sqldemo.R;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
public class MimeTypesTools {
private static boolean hasLoadMimeType = false;
/**
*
* @param context
* @param fileName
* @return 獲取檔案mime型別
*/
public static String getMimeType(Context context, String fileName) {
if (!TextUtils.isEmpty(fileName)) {
fileName = fileName.toLowerCase();
MimeTypes mimeTypes = getMimeTypes(context);
String extension = getSuffix(fileName);
return mimeTypes.getMimeType(extension);
}
return null;
}
/**
* 獲取檔案格式的字尾名 如 .jpg
* @param uri 指定檔案
* @return 如 .jpg
*/
public static String getSuffix(String uri) {
if (uri == null) {
return null;
}
int dot = uri.lastIndexOf(".");
if (dot >= 0) {
return uri.substring(dot);
} else {
// No extension.
return "";
}
}
private static MimeTypes getMimeTypes(Context context) {
return loadMimeTypes(context);
}
/**
* 解析xml 檔案
* @param context
* @return
*/
private static MimeTypes loadMimeTypes(Context context) {
MimeTypeParser parser = null;
XmlResourceParser xmlResourceParser = null;
if (!hasLoadMimeType) {
try {
parser = new MimeTypeParser(context, context.getPackageName());
xmlResourceParser = context.getResources().getXml(R.xml.mimetypes);
return parser.fromXmlResource(xmlResourceParser);
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
hasLoadMimeType = true;
}
return null;
}
}
package com.geely.mars.sqldemo.tools;
import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.content.res.XmlResourceParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class MimeTypeParser {
public static final String TAG_MIMETYPES = "MimeTypes";
public static final String TAG_TYPE = "type";
public static final String ATTR_EXTENSION = "extension";
public static final String ATTR_MIMETYPE = "mimetype";
public static final String ATTR_ICON = "icon";
private XmlPullParser mXpp;
private MimeTypes mMimeTypes;
private Resources resources;
private String packagename;
public MimeTypeParser(Context ctx, String packagename) throws NameNotFoundException {
this.packagename = packagename;
resources = ctx.getPackageManager().getResourcesForApplication(packagename);
}
public MimeTypes fromXml(InputStream in)
throws XmlPullParserException, IOException {
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
mXpp = factory.newPullParser();
mXpp.setInput(new InputStreamReader(in));
return parse();
}
public MimeTypes fromXmlResource(XmlResourceParser in)
throws XmlPullParserException, IOException {
mXpp = in;
return parse();
}
/**
* 對xml檔案的解析
* @return
* @throws XmlPullParserException
* @throws IOException
*/
public MimeTypes parse()
throws XmlPullParserException, IOException {
mMimeTypes = new MimeTypes();
int eventType = mXpp.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
String tag = mXpp.getName();
if (eventType == XmlPullParser.START_TAG) {
if (tag.equals(TAG_MIMETYPES)) {
} else if (tag.equals(TAG_TYPE)) {
addMimeTypeStart();
}
} else if (eventType == XmlPullParser.END_TAG) {
if (tag.equals(TAG_MIMETYPES)) {
}
}
eventType = mXpp.next();
}
return mMimeTypes;
}
private void addMimeTypeStart() {
String extension = mXpp.getAttributeValue(null, ATTR_EXTENSION);
String mimetype = mXpp.getAttributeValue(null, ATTR_MIMETYPE);
String icon = mXpp.getAttributeValue(null, ATTR_ICON);
if(icon != null){
int id = resources.getIdentifier(icon.substring(1) , null, packagename);
if(id > 0){
mMimeTypes.put(extension, mimetype, id);
return;
}
}
mMimeTypes.put(extension, mimetype);
}
}
package com.geely.mars.sqldemo.tools;
import android.webkit.MimeTypeMap;
import java.util.HashMap;
import java.util.Map;
public class MimeTypes {
private Map<String, String> mMimeTypes;
private Map<String, Integer> mIcons;
public MimeTypes() {
mMimeTypes = new HashMap<String,String>();
mIcons = new HashMap<String,Integer>();
}
/* I think the type and extension names are switched (type contains .png, extension contains x/y),
* but maybe it's on purpouse, so I won't change it.
*/
public void put(String type, String extension, int icon){
put(type, extension);
mIcons.put(extension, icon);
}
public void put(String type, String extension) {
// Convert extensions to lower case letters for easier comparison
extension = extension.toLowerCase();
mMimeTypes.put(type, extension);
}
public String getMimeType(String filename) {
String extension =MimeTypesTools.getExtension(filename);
// Let's check the official map first. Webkit has a nice extension-to-MIME map.
// Be sure to remove the first character from the extension, which is the "." character.
if (extension.length() > 0) {
String webkitMimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.substring(1));
if (webkitMimeType != null) {
// Found one. Let's take it!
return webkitMimeType;
}
}
// Convert extensions to lower case letters for easier comparison
extension = extension.toLowerCase();
String mimetype = mMimeTypes.get(extension);
if(mimetype==null) {
mimetype = "*/*";
}
return mimetype;
}
public int getIcon(String mimetype){
Integer iconResId = mIcons.get(mimetype);
if(iconResId == null) {
return 0; // Invalid identifier
}
return iconResId;
}
}
應用
如跳轉到支援開啟指定檔案格式的系統應用
try {
Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setAction(android.content.Intent.ACTION_VIEW);
String type = MimeTypesTools.getMimeType(context, path);
File file = new File(path);
//新增這一句表示對目標應用臨時授權該Uri所代表的檔案
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
if (file != null) {
Uri uri = null;
if (Build.VERSION.SDK_INT >= 24) {
uri = FileProvider.getUriForFile(context, context.getPackageName()+".fileprovider", file);
} else {
uri = Uri.fromFile(file);
}
if (uri != null) {
intent.setDataAndType(uri, type);
context.startActivity(intent);
}
}
} catch (Exception e) {
e.printStackTrace();
ToastUtil.show("手機上無可開啟此格式的app");
}