.J File Extension

3 file types use the .j file extension.
File Type 1

Java Source File

Developer Oracle
3.1  |  34 Votes
Category Developer Files
Format Text

What is a J file?

Contains program source code written in the Java programming language; may include the source code for a complete program or may be one of many files referenced by a Java programming project.

More Information

Java source files most often have a .JAVA extension.

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Programs that open or reference J files

Updated August 17, 2010
File Type 2

JAR Archive

Developer N/A
3.2  |  6 Votes
Category Compressed Files
Format N/A

What is a J file?

Compressed file archive created with JAR, the successor to the ARJ file compression program (which created .ARJ files); JAR is available in a 16-bit DOS version and a 32-bit Windows version.

More Information

Not related to the .JAR format, which is a Java Archive.

Programs that open J files

ARJ Software JAR
Updated December 14, 2006
File Type 3

JPEG Image

Developer N/A
2.8  |  6 Votes
Category Raster Image Files
Format Binary

What is a J file?

Compressed graphic that uses .JPEG image compression; may contain thousands of colors, which makes it a good format for storing digital photos; can use different levels of compression, but the more compression is used, the lower the quality of the resulting image.

More Information

Most JPEG files have a .JPG extension.

Programs that open J files

Updated February 15, 2007

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