The DJUTILS DATA project contains packages for managing, writing and reading tabular structured data. Data can be written and read in several formats:
This could be extended with storage in various databases, etc.
No matter what storage is used, the stored data is accompanied by some meta-data that describes the data in each column. This meta-data is needed to reconstruct the tabular structed data when reading. For CSV and TSV data, the meta-data is stored in a separate file, for JSON and XML, the meta-data is stored in the same file.
When in-memory, the data can be read and written using the functions defined in the java Interface. It is not possible to delete particular records. Of course, an entire in-memory table can be deleted by dropping all references to it (and letting the garbage collector do its work). A table on disk can be deleted by deleting the file(s).
Maven is one of the easiest ways to include DJUTILS-DATA in a Java project. The Maven files for reside at https://djutils.org/maven. When a POM-file is created for the project, the following snippet needs to be included to include DJUTILS-DATA:
<dependencies> <dependency> <groupId>org.djutils</groupId> <artifactId>djutils-data</artifactId> <version>1.04.12</version> </dependency> ... other dependencies go here ... </dependencies>
Of course, the version number (1.04.12 in the above example) needs to be replaced with the version that one wants to include in the project.
Right now, the DJUTILS-DATA files are kept on a server at TU Delft, and are not yet made available on Maven Central. Therefore, the repository location has to be specified separately in the Maven POM-file:
<repositories> <repository> <name>djutils Public Repository</name> <id>djutils</id> <url>https://djutils.org/maven</url> </repository> ... other repositories go here ... </repositories>