What is a Jar?
If you are a Java programmer, you may be already familiar with JAR files. These are files that contain program files, as well as their manifests, all compressed into a single file.
You can see their contents using a text editor, but it is recommended to use dedicated software.
Definition
A jar is a container, generally of a round or cylindrical shape, made of glass, earthenware or other material. It is usually fitted with a lid. A jar may be filled with various contents such as food, medicines and other items.
A Jar can also be used as a noun to describe the quantity that such a container holds or the sound it produces when shaken. In the latter sense, jarring is often used to describe a grating, harsh or disturbing effect.
The term Jar can also refer to a Java Archive file (JAR). Inspired by the popular ZIP files, JAR format was developed to aggregate all components of an application into one package for distribution and installation. JAR files can contain compiled Java class files, supporting metadata, configuration files and resources like text files, images, audio etc. They can also carry a digital signature attesting to the integrity of the file or individual entries within it.
The jar utility creates a zipped JAR file by reading the list of files specified on the command line in a space-separated order. It can be augmented with the -m option to store additional, simple kinds of attribute information about the archived files. In this case, jar reads the manifest file containing this additional information before the list of input files and then adds the files to the archive with a.jar extension.
Origin
The jar is one of the most iconic products in modern history. It is as recognized in the kitchen as it is on the shelf and is a beloved staple among foodies, DIYers, and designers. The jar’s popularity is no doubt tied to its practicality and ease of use. It is also a symbol of America’s ingenuity.
Jar is derived from the Middle English verb to jar, which in its earliest sense meant “to talk gibberish.” The verb was probably echoic, based on Latin garrire (to chatter) and Ampoule Dropper Old French jaue (“a sound like that of a bird screech”). In 1520s, it acquired an additional meaning of to make harsh or discordant in tone, influenced by the sound of a grating door.
In 1858, New Jersey tinsmith John Landis Mason patented threaded screw-top lids for glass home-canning jars. Prior to this invention, home canning was an inefficient process that required the use of wax to create an airtight seal above the contents of a jar.
During World War II, sailors began calling members of the Marine Corps as “Jarheads.” It isn’t clear how this nickname developed, but it may have something to do with the high collar on the Marine Dress Blues uniform that some people believe makes a Marine’s head look like a jar. More recently, the term has also come to refer to any member of the military, regardless of branch.
Synonyms
A jar is a cylindrical container made of glass or earthenware with a wide mouth or opening that can be closed by a lid, screw cap, lug cap, or cork stopper. Jars are often used to store food, such as jam or pickles. They are also used for other purposes, such as holding candles, storing paint, or containing water. There are several types of jars, including Mason jars, ball jars, wide-mouth mason jars, and pickle jars. The term jar is also sometimes used to refer to a specific type of wine bottle, such as a Claret bottle or a Bordeaux bottle.
To have a disruptive or disturbing effect on someone: The noise jarred my nerves.
To cause something to shake or vibrate: The explosion jarred the window frames.
Related words are basin, bottle, can, flask, flowerpot, jug, pot, and vase.
In terms of product packaging, jars are a great choice for many different applications. The thread size and dimension are Ampoule Dropper important to consider when purchasing a jar, as these factors determine how much product can fit inside the container. Thread size is another way to refer to a jar’s neck finish, which is the protrusion on top of the jar where a lid or closure is fastened. The dimensions refer to the size of the jar itself, such as its height, width, and depth.
Usage
A jar is a round, smooth-sided container. It’s usually made of glass and used for storing food from rice to tea bags to cookies. It can also be used to store liquids such as coffee or juice. A jar is sometimes called a bottle, a pot, or a tin. Jars were historically used for storage of medicines, but now they are most often used in the kitchen. They can be made from ceramics or, more commonly in modern centuries, clear glass. A jar can be a straight-sided cylinder or one with rotationally symmetric decorative curves. A jar may also have a glass disc foot separated from the main body of the jar.
Jar files (Java Archive) are a file format for packaging multiple Java class files together into a single file. These files can include compiled source code, an optional manifest file and other related data such as XML-based configuration data or JSON-based data files. The files can be compressed, which makes them easier to transfer across the Internet. A jar file can be digitally signed by the applet author for ownership authentication and integrity protection.
To inspect a Jar file’s contents, you can use any ZIP program such as 7-Zip, WinZip and RARLAB WinRAR (Windows), or PeaZip (Linux). Alternatively, you can use the jar tool from the command line. The first argument specifies the name of the jar file to process, and the second argument, if omitted, refers to the list or table that is written on standard output.
