md5 ‘;’ RESOURCE

Calculate MD5 digest of a resource in the bundle

Summary

The md5 macro calculates the MD5 hash of a resource that exists within the current bundle JAR. The result can be returned as either Base64 (default) or hexadecimal encoding.

Syntax

${md5;<resource-path>[;<encoding>]}

Parameters

resource-path - Path to a resource within the bundle (e.g., “META-INF/MANIFEST.MF”)
encoding (optional) - Output encoding: “hex” for hexadecimal, “base64” for Base64 (default)

Behavior

Locates the resource within the bundle being built
Calculates the MD5 digest of the resource contents
Returns the digest in the specified encoding (Base64 by default)
Throws an exception if the resource is not found

Examples

Get MD5 of a resource (Base64):

${md5;META-INF/services/com.example.Service}
# Returns Base64-encoded MD5

Get MD5 in hexadecimal format:

${md5;config/application.properties;hex}
# Returns: "5d41402abc4b2a76b9719d911017c592" (example)

Hash manifest file:

manifest.md5=${md5;META-INF/MANIFEST.MF;hex}

Verify resource integrity:

Bundle-ResourceMD5: ${md5;important-config.xml}

Use Cases

Verifying resource integrity in bundles
Generating resource checksums for validation
Creating content-based identifiers
Implementing resource version checking
Integrity verification in manifests
Detecting resource tampering

Notes

Resource path is relative to the bundle root
Only works with resources that are part of the bundle being built
MD5 is considered cryptographically weak; use for checksums only, not security
Default encoding is Base64
Hex encoding produces lowercase hexadecimal strings
Throws FileNotFoundException if resource doesn’t exist
See also: ${sha1} and ${digest} for other hash algorithms

See test cases in MacroTestsForDocsExamples.java

md5 ';' RESOURCE