假设我有一个完整的文件路径:(/sdcard/tlogo.png)。我想知道它的mime类型。
我为它创建了一个函数
public static String getMimeType(File file, Context context)
{
Uri uri = Uri.fromFile(file);
ContentResolver cR = context.getContentResolver();
MimeTypeMap mime = MimeTypeMap.getSingleton();
String type = mime.getExtensionFromMimeType(cR.getType(uri));
return type;
}
但当我调用它时，它返回null。
File file = new File(filePath);
String fileType=CommonFunctions.getMimeType(file, context);
当前回答
而从资产/文件(注意，在MimeTypeMap中缺少一些情况)。
private String getMimeType(String path) {
if (null == path) return "*/*";
String extension = path;
int lastDot = extension.lastIndexOf('.');
if (lastDot != -1) {
extension = extension.substring(lastDot + 1);
}
// Convert the URI string to lower case to ensure compatibility with MimeTypeMap (see CB-2185).
extension = extension.toLowerCase(Locale.getDefault());
if (extension.equals("3ga")) {
return "audio/3gpp";
} else if (extension.equals("js")) {
return "text/javascript";
} else if (extension.equals("woff")) {
return "application/x-font-woff";
} else {
// TODO
// anyting missing from the map (http://www.sitepoint.com/web-foundations/mime-types-complete-list/)
// reference: http://grepcode.com/file/repo1.maven.org/maven2/com.google.okhttp/okhttp/20120626/libcore/net/MimeUtils.java#MimeUtils
}
return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
}
而使用ContentResolver
contentResolver.getType(uri)
当http/https请求
try {
HttpURLConnection conn = httpClient.open(new URL(uri.toString()));
conn.setDoInput(false);
conn.setRequestMethod("HEAD");
return conn.getHeaderField("Content-Type");
} catch (IOException e) {
}
其他回答
// new processing the mime type out of Uri which may return null in some cases
String mimeType = getContentResolver().getType(uri);
// old processing the mime type out of path using the extension part if new way returned null
if (mimeType == null){mimeType URLConnection.guessContentTypeFromName(path);}
上面的MimeTypeMap解决方案在我的使用中返回null。这很有效，而且更简单:
Uri uri = Uri.fromFile(file);
ContentResolver cR = context.getContentResolver();
String mime = cR.getType(uri);
public static String getFileType(Uri file)
{
try
{
if (file.getScheme().equals(ContentResolver.SCHEME_CONTENT))
return subStringFromLastMark(SystemMaster.getContentResolver().getType(file), "/");
else
return MimeTypeMap.getFileExtensionFromUrl(file.toString()).toLowerCase();
}
catch(Exception e)
{
return null;
}
}
public static String getMimeType(Uri file)
{
try
{
return MimeTypeMap.getSingleton().getMimeTypeFromExtension(getFileType(file));
}
catch(Exception e)
{
return null;
}
}
public static String subStringFromLastMark(String str,String mark)
{
int l = str.lastIndexOf(mark);
int end = str.length();
if(l == -1)
return str;
return str.substring(l + 1, end);
}
而从资产/文件(注意，在MimeTypeMap中缺少一些情况)。
private String getMimeType(String path) {
if (null == path) return "*/*";
String extension = path;
int lastDot = extension.lastIndexOf('.');
if (lastDot != -1) {
extension = extension.substring(lastDot + 1);
}
// Convert the URI string to lower case to ensure compatibility with MimeTypeMap (see CB-2185).
extension = extension.toLowerCase(Locale.getDefault());
if (extension.equals("3ga")) {
return "audio/3gpp";
} else if (extension.equals("js")) {
return "text/javascript";
} else if (extension.equals("woff")) {
return "application/x-font-woff";
} else {
// TODO
// anyting missing from the map (http://www.sitepoint.com/web-foundations/mime-types-complete-list/)
// reference: http://grepcode.com/file/repo1.maven.org/maven2/com.google.okhttp/okhttp/20120626/libcore/net/MimeUtils.java#MimeUtils
}
return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
}
而使用ContentResolver
contentResolver.getType(uri)
当http/https请求
try {
HttpURLConnection conn = httpClient.open(new URL(uri.toString()));
conn.setDoInput(false);
conn.setRequestMethod("HEAD");
return conn.getHeaderField("Content-Type");
} catch (IOException e) {
}
是否也返回空值 在我的案例中，路径是
/storage/ emululated /0/Music/01 - Ghost on the Dance Floor.mp3
在工作中使用
瓦尔·奥尼。replace(“”、“”)
方法是这样的
@JvmStatic
fun getMimeType(inUrl: String?): String {
if (inUrl == null) return ""
val url = inUrl.replace(" ","")
var type: String? = null
val extension = MimeTypeMap.getFileExtensionFromUrl(url)
if (extension != null) {
type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase())
}
if(type ==null){
val cR = WifiTalkie.getApplicationContext().contentResolver
type = cR.getType(Uri.parse(url))
}
if (type == null) {
type = "*/*" // fallback method_type. You might set it to */*
}
return type
}
结果返回成功结果:
音频/ mpeg
希望能对大家有所帮助
