Android supports the Java class library of ExiFinterface: Introduction and usage
Android supports the Java class library of ExiFinterface: Introduction and usage
Introduction:
ExiFinterface is a class library provided by Android for EXIF data for reading and editing images.ExiF (Exchangeable Image File Format) is a format that is commonly used to store photo metadata, including the shooting date, camera model, aperture, focal length and other information.Through the ExiFinterface class, developers can easily read and edit these information in order to perform various operations in the application, such as exif information displayed, rotating photos, editing shooting date, etc.
usage:
1. Import in the class library
Add the following dependencies to the project's Build.gradle file to import the ExiFinterface class library:
groovy
implementation 'androidx.exifinterface:exifinterface:1.3.0'
2. Create an ExiFinterface object
When you need to process EXIF data, create an ExiFinterface object.For example, you can read the EXIF information of the photo in the following way:
ExifInterface exifInterface = new ExifInterface("path/to/image.jpg");
Here, replace "PATH/To/Image.jpg" to the path of actual photos.
3. Read EXIF data
Once an ExiFinterface object is created, you can use its acquisition method to read specific exif information.Here are some commonly used examples:
String dateTime = exifInterface.getAttribute(ExifInterface.TAG_DATETIME);
String cameraModel = exifInterface.getAttribute(ExifInterface.TAG_MODEL);
float aperture = exifInterface.getAttributeFloat(ExifInterface.TAG_APERTURE_VALUE, 0f);
Here, tag_datetime, tag_model, and tag_aperture_value are the constant provided by ExiFinterface, which means the EXIF tags that need to be read.
4. Edit EXIF data
The ExiFinterface class also provides some settings to edit EXIF data.For example, you can use the following code setting to set the shooting date to the current date:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss", Locale.getDefault());
String currentDate = dateFormat.format(new Date());
exifInterface.setAttribute(ExifInterface.TAG_DATETIME, currentDate);
exifInterface.saveAttributes();
In this example, we use the tag_datetime constant to specify the EXIF tags that need to be set, and change the change to the photo by calling the saveattributes () method.
Through the above steps, you can use ExiFinterface class libraries in Android applications to read and edit photos of EXIF data.
Precautions:
1. Before reading or editing EXIF data, ensure that the path of the photo is correct, and the application has the permissions to access the path.
2. The value of some ExiF tags may be NULL or empty string, so corresponding inspections and processing need to be performed during use.
3. When editing EXIF data, make sure that the attributes that need to be set up before calling Saveattributes () can be set to change to the photo successfully.
The above is the introduction and usage of the ExiFinterface class library supported by Android.
