GroupDocs.Metadata also works without the license in trial mode with certain limitations
Evaluation version limitations
You can easily download GroupDocs.Metadata for evaluation. The evaluation download is the same as the purchased download. The evaluation version simply becomes licensed when you add a few lines of code to apply the license. You will face following limitations while using the API without the license.
API
Limitations
Document properties (Pdf, Word, Excel, PowerPoint, Visio, etc)
Only first 5 properties can be read
XMP API
Only first 2 XMP schemes can be read
EXIF API
GPS IFD and image thumbnail are unavailable
Only first 5 properties can be read
IPTC API
Only first 5 properties can be read
Id3v2, Lyrics3, APEv2 tags
Only first 5 properties can be read
QuickTime atoms
Only first 5 atoms can be read
File open
Open maximum 15 files, otherwise, API throws exception
File save
Not supported in trial mode
Licensing
The license file contains details such as the product name, number of developers it is licensed to, subscription expiry date and so on. It contains the digital signature, so don’t modify the file. Even inadvertent addition of an extra line break into the file will invalidate it. You need to set a license before utilizing GroupDocs.Metadata API if you want to avoid its evaluation limitations.
The license can be loaded from a file or stream object.
Applying license from file
The code below will explain how to apply a product license.
Calling License.setLicense multiple times is not harmful but simply wastes processor time. It is called once when the application starts.
Applying Metered license
Note
You can also set Metered license as an alternative to license file. It is a new licensing mechanism that will be used along with existing licensing method. It is useful for the customers who want to be billed based on the usage of the API features. For more details, please refer to Metered Licensing FAQ section.
Here are the simple steps to use the Metered class.
Create an instance of Metered class.
Pass public & private keys to [setMeteredKey](https://reference.groupdocs.com/metadata/java/com.groupdocs.metadata.licensing/Metered#setMeteredKey(java.lang.String,%20java.lang.String)) method.
Do processing (perform task).
call method [getConsumptionQuantity](https://reference.groupdocs.com/metadata/java/com.groupdocs.metadata.licensing/Metered#getConsumptionQuantity()) of the Metered class.
It will return the amount/quantity of API requests that you have consumed so far.
call method [getConsumptionCredit](https://reference.groupdocs.com/metadata/java/com.groupdocs.metadata.licensing/Metered#getConsumptionCredit()) of the Metered class (Since version 19.5).
It will return the credit that you have consumed so far.
Following is the sample code demonstrating how to use Metered class.