Common Exceptions and Errors Involving Fonts on Linux
Missing text or images (emf or wmf) when code is executed on Linux
This problem occurs in systems with restrictions in these cases:
- When there are no fonts installed or when the font folder for the java process cannot be accessed
- When the TEMP directory cannot be accessed.
Solution
Check and confirm that access to the TEMP directory and the fonts folder has been granted.
Workaround
Use FontsLoader to load the required fonts without installing them:
FontsLoader.loadExternalFonts(pathToFontsFolders);
If the TEMP directory cannot be accessed, use this code to specify another directory as the TEMP for Java:
String newTempFolder = “pathToTmpFolder”; String oldValue = System.getProperty(“java.io.tmpdir”); java.io.File file = new java.io.File(newTempFolder); if (!file.exists()) file.mkdir(); System.setProperty(“java.io.tmpdir”, newTempFolder); try {
FontsLoader.loadExternalFonts(pathToFontsFolders);
Presentation pres = ...
# ....
} finally { System.setProperty(“java.io.tmpdir”, oldValue); }
Exception: InvalidOperationException: Cannot find any fonts installed on the system
This exception occurs when
- the Java process cannot access the fonts folder
- no fonts have been installed.
Solution
-
Check and confirm that access to the font folder for the Java process has been granted.
-
Install some fonts or use FontsLoader.
-
Install fonts.
- Ubuntu:
```
sudo apt-get update
sudo apt-get install -y fonts-dejavu-core
fc-cache -fv
```php
```
* CentOS:
```php
```
sudo yum makecache
sudo yum -y install dejavu-sans-fonts
fc-cache -fv
```php
```
* Using [FontsLoader](https://reference.aspose.com/slides/php-java/aspose.slides/FontsLoader):
```php
```
FontsLoader.loadExternalFonts(pathToFontsFolders);
```php
```
## **Exception: NoClassDefFoundError: Could not initialize class com.aspose.slides.internal.ey.this**
This exception occurs on a Linux system that lacks fontconfig and fonts.
### Solution:
Install fontconfig:
* Ubuntu:
```php
sudo apt-get update sudo apt-get -y install fontconfig
- CentOS:
sudo yum makecache sudo yum -y install fontconfig
Additionally, some open-jdk versions (for example, alpine JDK) also require installed fonts.
- Ubuntu:
sudo apt-get install -y fonts-dejavu-core fc-cache -fv
- CentOS:
sudo yum -y install dejavu-sans-fonts fc-cache -fv
Exception: UnsatisfiedLinkError: libfreetype.so.6: cannot open shared object file: No such file or directory
This exception occurs on a Linux system that lacks the libfreetype library.
Solution:
Install libfreetype and fontconfig:
- Ubuntu:
sudo apt-get update sudo apt-get install libfreetype6 sudo apt-get -y install fontconfig
- CentOS:
sudo yum makecache sudo yum install libfreetype6 sudo yum -y install fontconfig