在软件领域，JAR文档（Java归档，英语：Java ARchive）是一种软件包文档格式，通常用于聚合大量的Java类文档、相关的元数据和资源（文本、图片等）文档到一个文档，以便分发Java平台应用软件或库。[3]

JAR文档是一种归档文档，以ZIP格式构建，以.jar为文档扩展名。用户可以使用JDK自带的jar命令创建或提取JAR文档。也可以使用其他zip压缩工具，不过压缩时zip文档头里的条目顺序很重要，因为Manifest资源配置文档常需放在首位。JAR文档内的文档名是Unicode文本。

In software, JAR (Java Archive) is a package file format typically used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into one file to distribute application software or libraries on the Java platform.

JAR files are fundamentally archive files. They are built on the ZIP file format and have the .jar file extension. Computer users can create or extract JAR files using the jar command that comes with a JDK. They can also use zip tools to do so, however the order of entries in the zip file headers is important when compressing, as the manifest often needs to be first. Inside a JAR, file names are Unicode text.