Disable encoding checking in java gradle project - gradle

Question

I want to migrate one of our java projects from ant to gradle. This project has got a lot of source code wrote by few programmers. The problem is that some of files are encoded in ANSi and some in UTF-8 (this generates compile errors). I know that I can set encoding using compileJava.options.encoding = 'UTF-8' but this will not work (not all files are encoded in UTF-8). Is it possible to disable encoding checking (I don't want to change encoding of all files)?

Answer 1

This is not an issue with Gradle but with javac. However, you can solve this issue running a one-time groovy script in your gradle build as described below.
Normally you'd only need to add following line to your build.gradle file:
compileJava.options.encoding = 'UTF-8'
However, some text editors when saving files to UTF-8 will generate a byte order mark (BOM) header at the beginning of the text files.
And javac does not understand the BOM, not even when you compile with encoding="UTF-8" option so you're probably getting an error such as this:
> javac -encoding UTF8 Test.java
Test.java:1: error: illegal character: \65279
?class Test {
You need to strip the BOM from your source files or convert your source file to another encoding. Notepad++ for example can convert the file encoding from one to another.
For lots of source files you can easily write a simple task in Groovy/Gradle to open your source text files and convert the UTF-8 removing the BOM prefix from the first line if found.
Add this to your build.gradle and run gradle convertSource
task convertSource << {
// convert sources files in source set to normalized text format
sourceSets.main.java.each { file ->
// read first "raw" line via BufferedReader
def r = new BufferedReader(new FileReader(file))
String s = r.readLine()
r.close()
// get entire file normalized
String text = file.text
// get first "normalized" line
String normalizedLine = new StringReader(text).readLine()
if (s != normalizedLine) {
println "rename: $file"
File target = new File(file.getParentFile(), file.getName() + '.bak')
if (!target.exists()) {
if (file.renameTo(target))
file.setText(text)
else
println "failed to rename or target already exists"
}
}
}
} // end task
The convertSource task will simply enumerate all of the source files, read first "raw" line from each source file then read the normalized text lines and compare first lines. If the first line is different then it would output a new target file with the normalized text and save backup of the original source. Only need to run convertSource task one-time after which you can remove original source files and the compile should work without getting encoding errors.