mavenmon

like nodemon but for maven projects

Installation

npm install -g mavenmon

Usage

Go to your maven project root and run

mavenmon 

This will automatically start watching your project with the default settings

You can also override some functionalities by defining different logic in the command line

mavemon some_dir onchange_handler.js --filter file_filter.js

• some_dir - defines which dir to watch

• onchange_handler.js - define a different behavior when file changes. See spec below.

• file_filter.js - defines which files should be watched and which should not. See spec below.

On change handler

For example

/**
   A change handler that assumes this is a multi module project and runs maven build on relevant artifact when code changes. 
   Otherwise ignores.
**/
module.exports = function (data) {
  return new Promise(function (resolve, reject) {
    try {
      if (data.path.endsWith('.java')) {
        console.log('running mvn clean install')
        execSync('mvn clean install -DskipTests=true -nsu -pl ' + data.pom.project.artifactid, {stdio: [0, 1, 2]})
      } else {
        console.log('unhandled path [' + data.path + ']', data.type)
      }
    } catch (e) {
      reject(e)
      return
    } finally {
      console.log('finished process [' + data.path + ']', data.type)
    }
    resolve()
  })
}

As you can see onchange_handler.js must expost a function that receives as a parameter the modified data. Specifically these fields

• dir - [string] - the pom directory
• pom - [object] - an object in the pom.xml structure. all the keys are lowercase (artifactid and not artifactId)
• jarfile - [string] - a guess where the jar file will be.
• classfile - [string] - a guess where the class file will be.

File filter

For example

var fs = require('fs')
var path = require('path')

/**

    A file filter that focuses on java files under src, on compiled classes from src and jar files.

**/

module.exports = function shouldWatchFolder (filepath) {
  try {
    var result = false
    if (fs.existsSync(filepath)) {
      if (fs.lstatSync(filepath).isDirectory() &&
        path.basename(filepath) !== 'node_modules' &&
        path.basename(filepath) !== 'test-classes' &&
        filepath.indexOf('src/test/java') < 0 &&
        path.basename(filepath) !== 'dev' && (filepath === '.' || path.basename(filepath)[0] !== '.')) {
        result = true
      }

      if (filepath.endsWith('.java') || filepath.endsWith('.class') || filepath.endsWith('.jar')) {
        result = true
      }
    } else {
      return true // if does not exist, watch it! otherwise will be ignored if readded. fixes issue where file is deleted.
    }
  } catch (e) {
    console.log('should i ignore error', e)
    result = false
  }
  return result
}

The file filter should expose a function that returns true if should be ignored.

NOTE - if file does not exist, you might still want to watch it in case it returns. If you return false, then mavenmon will not detect it if it comes back.