adambien/zb

zb - Zero Dependencies Builder

Build single-module Java 25+ projects into executable JARs without Maven or Gradle.

How to Build

Step 1: Check for zb.sh script

Search for a zb.sh wrapper script in this order — stop at the first match:

1. zb.sh in the project root
2. Glob for **/zb.sh within the project directory tree
3. Glob for **/zb.sh one level above the project (sibling projects)
4. Check ~/bin/zb.sh or ~/.local/bin/zb.sh

If zb.sh is found, skip to Step 3 (zb.sh) — the script handles jar location and execution internally.

If zb.sh is not found, continue to Step 2 to locate zb.jar manually.

Step 2: Find zb.jar (only if zb.sh not found)

Locate zb.jar in this order — stop at the first match:

1. zb.jar in the project root
2. Glob for **/zb.jar within the project directory tree
3. Glob for **/zb.jar one level above the project (sibling projects)
4. Check ~/bin/zb.jar or ~/.local/bin/zb.jar

If neither zb.sh nor zb.jar is found, tell the user to download from github.com/AdamBien/zb.

Step 3: Find the build directory

zb must run from the directory containing the .zb config file (or where one should be generated). In multi-module repos, this is the module subdirectory, not the repo root.

• Glob for .zb files in the project
• cd into the directory containing the .zb file before running zb
• If no .zb exists, run from the directory that contains src/main/java

Step 4: Run the build

With zb.sh:

cd <build-directory> && <path-to-zb.sh>

With zb.jar (fallback):

cd <build-directory> && java -jar <path-to-zb.jar>

Step 5: Verify

Check exit code and output. A successful build prints the number of compiled files. Common errors:

• "Multiple main classes found" — you are in the wrong directory (likely the repo root instead of a module subdirectory)
• Compilation errors — fix the source and rebuild

Source Directory Convention

zb auto-detects sources in order:

1. src/main/java (Maven convention, preferred)
2. src/
3. Current directory .

Resources auto-detected from src/main/resources or current directory.

Entry Point Requirement

The project must have exactly one class with a void main( method (Java 25+ unnamed main).

Configuration (.zb)

Optional .zb properties file in the build directory (auto-generated on first run):

sources.dir=<discovered by zb>
resources.dir=<discovered by zb>
classes.dir=<temp.dir>
jar.dir=zbo/
jar.file.name=app.jar

• <discovered by zb> — auto-detect directory
• <temp.dir> — use temporary directory, cleaned after build

CLI Arguments (Positional)

java -jar zb.jar [sources] [classes] [jar_dir] [jar_file]

Precedence: CLI args > .zb file > defaults.

Output

Default: zbo/app.jar — executable JAR with Main-Class manifest entry.

Run with:

java -jar zbo/app.jar

Constraints

• Java 25+ required
• No external dependency support (no Maven/Gradle dependency resolution)
• Single-module projects only
• Exactly one main class per project

After a Successful Build

If the project has a test/ directory containing *Test.java files, ask the user if they want to run tests with /zunit.