I've got the following task:
preBuild.dependsOn "copyConfigFile"
task copyConfigFile(type: Copy) {
from 'ConfigSources/VersionInfo.java'
into 'src/main/java/com/company/gradleexperiments/'
expand([changeset: "12345",
changeset_time: "the time",
changeset_date : "the date"])
}
Its works as expected except after the file has been initially copied, if I change one of the values in the expand and build again, then the file is not being overwritten (the creation timestamp of the file in the target destination remains that last time it was built).
I did some googling and searching of past questions on this topic, however the answer I got was that the gradle copy task is by default always supposed to overwrite the file. If that is the case, then why is it not doing so for me?
This is a very old bug: the copy task doesn't consider the values passed to expand as inputs, and thus considers it's up-to-date even though these values have changed.
You can vote on this issue here.
This should be relatively easy to circumvent by adding the expanded values to the input explicitely. For example:
task copyConfigFile(type: Copy) {
from 'ConfigSources/VersionInfo.java'
into 'src/main/java/com/company/gradleexperiments/'
def values =
['changeset': '12345',
'changeset_time': 'the time',
'changeset_date': 'the date'];
inputs.properties(values);
expand(values);
}
Related
Let's say there is a Gradle task that produces an artifact. For example, a Zip task:
tasks.register("myZip", Zip) {
...
}
Would the following task of type Copy automatically gain a dependency on task myZip?
task copyMyZips(type: Copy) {
from { subprojects.findAll { it.tasks.findByName('myZip') }.myZip }
into '/tmp'
}
Note the really convoluted way of referring to the task myZip.
Yes. The Copy tasks do gain dependency on task outputs and tasks which are mentioned in their from blocks.
Per documentation of method from in class Copy as of Gradle 7.4:
AbstractCopyTask from(Object sourcePath, Closure c)
Specifies the source files or directories for a copy and creates a child CopySourceSpec. The given source path is evaluated as per Project.files(java.lang.Object[]).
in turn, documentation of Project.files(java.lang.Object[]) (emphasis mine):
Returns a ConfigurableFileCollection containing the given files. You can pass any of the following types to this method:
[...most of the list snipped...]
A Task. Converted to the task's output files. The task is executed if the file collection is used as an input to another task.
A TaskOutputs. Converted to the output files the related task. The task is executed if the file collection is used as an input to another task.
Unfortunately, the documentation of Copy does not refer to what is passed into method from as "inputs". However, judging by the code of AbstractCopyTask.java every change to the CopySpec of the Copy task is propagated to the inputs via a ChildSpecListener. The listener is added to the field CopySpecInternal rootSpec .
I have a directory, let's call it inputs. I need to create a task that will:
read in all of the files in the inputs directory, ie: inputs/*.
produce a new file somewhere else that combines these files in some way. (For the sake of example, you can assume I just want to concatenate all of the files into a single output file.)
How do I set up the task correctly such that the following requirements are met?
requesting the task a second time when nothing has changed doesn't execute the task ("Already up to date").
adding, editing, or deleting files in the inputs directory causes the task to be "out of date", and so requesting it after any of those has happened will cause it to re-execute.
I'm relatively new to gradle and trying to set up a backup task. I have a few examples, first I'll describe the goal:
I have a number of files in a directory (call it the "data directory"). When the contents of Any File in this data directory are modified, I want to create a new directory in a "backup location" and copy Every File in the data directory into the directory that was just created. The name of the directory created will contain the current date and time. For now, the data directory contains no subdirectories.
I had this working fine when the "data directory" contained one file and all I wanted to do was rename that file to include the date. Example:
task copyDocs(type: Copy) {
from 'src/main/doc/testfile.html'
into 'build/target/doc'
rename { String fileName ->
def date = new Date();
date.format("YYYY-MM-dd--HH-mm-ss") + " " + fileName
}
}
This worked great. I could run the task "copyDocs" as many times as I wanted, but it would only create a new file if I had actually modified the contents of testfile.html. Now, I wanted to expand this so that instead of creating a new file that got renamed, it would create a new directory and copy the source file into it.
task copyDocs(type: Copy) {
def dateStr = (new Date()).format("YYYY-MM-dd--HH-mm-ss");
from 'src/main/doc/testfile.html'
into 'build/target/doc/' + dateStr
}
This did not work so great. While the directory that gets created has the name I wanted, the problem is that Every Time I run the task, it creates a new directory and copies testfile.html into it, regardless of whether this file was modified.
I know this has something to do with the 'task inputs' and such, and I have read the parts of the documentation that describe the initialization phase vs. the configuration phase and so on. What I have not found is anything specific enough to help me understand why the copy task believes it needs to be re-run in the second case but not in the first case.
Simply put, in both cases, the potential output file(s) change every time the task is run as a function of the date/time. The input file(s) Do Not Change in the case of either task. So why does the second task need to be re-run every time, but not the first task? Is there a straightforward way to "debug" gradle so that it explicitly tells me why this is?
Your time and help are greatly appreciated, I am interested in learning more about gradle as it seems like an effective and modern build system!
When it comes to copy task whether it will be executed is determined by task's inputs and outputs which are set during configuration phase (see here). Since at configuration phase output is different every time:
into 'build/target/doc/' + dateStr
(it depends on seconds, but if you trim to hours, days, months the effect will be the same but rarer) the file is copied every time the task is executed even though it hasn't changed. To fix the problem you need to alter the destination at the execution time which can be done in the following way:
task copyDocs(type: Copy) {
def dest = 'build/target/doc/'
from 'src/main/doc/testfile.html'
into dest
eachFile { fcp ->
def dateStr = (new Date()).format("YYYY-MM-dd--HH-mm-ss");
fcp.path = dest + dateStr
}
}
This way task will be executed if and only if from input differs.
is it possible to exclude an element from the output files of a Task in order to not consider it for the up-to-date check? In my case I have a copy task that automatically set the destination directory in outputs variable, but I'd like to remove it and set only some of the copied files.
Or, as alternative, is it possible to overwrite the entire outputs variable?
Thanks,
Michele.
Incremental tasks create snapshots from input and output files of a task. If these snapshots are the same for two task executions (based on the hash code of file content), then Gradle assumes that task is up-to-date.
You are not able to remove some files from output and expect Gradle to forget about them, simply because the hash codes will be different.
There is an option that allows you to manually define the logic of up-to-date checks.
You should use a method upToDateWhen(Closure upToDateClosure) in TaskOutputs class.
task myTask {
outputs.dir files('/home/user/test')
outputs.upToDateWhen {
// your logic here
return true; // always up-to-date
}
}
I've found the solution:
task reduceZip(type: Copy) {
outputs.files.setFrom(file("C:/temp/unzip/test.properties"))
outputs.file(file("C:/temp/unzip/test.txt"))
from zipTree("C:/temp/temp.zip")
into "C:/temp/unzip"
}
Outputs.files list could be modified only register new elements, not removing (for what I know). So I need to reset the list and then eventually add other files. The outputs.files.setFrom method reset the outputs.files list so it is possible add other file. In the example above I reduce the up-to-date check only to the test.properties and test.txt files.
As part of a deploy task in Gradle, I want to change the value of a property in foo.properties to point to a production database instead of a development database.
I'd rather not replace the whole file outright, as it's rather large and it means we would have to maintain two separate versions that only differ on a single line.
What is the best way to accomplish this?
You can use the ant.propertyfile task:
ant.propertyfile(
file: "myfile.properties") {
entry( key: "propertyName", value: "propertyValue")
entry( key: "anotherProperty", operation: "del")
}
You should be able to fire off an ant "replace" task that does what you want: http://ant.apache.org/manual/Tasks/replace.html
ant.replace(file: "blah", token: "wibble", value: "flibble")
Create a properties object, then create the file object with the targeted properties file path, load the file on the properties object with load, set the desired property with setProperty, and save the changes with store.
def var = new Properties()
File myfile = file("foo.properties");
var.load(myfile.newDataInputStream())
var.setProperty("db", "prod")
var.store(myfile.newWriter(), null)
A simple solution is to code a task that uses java.util.Properties to write the file. If you really want to incrementally update the file, you'll have to implement this on your own. Or maybe you find an Ant task that does what you want (all Ant tasks can be used as-is from Gradle). For best results, you should also declare the inputs and outputs of the task, so that Gradle only executes the tasks when the properties file needs to be changed.
You can use ReplaceTokens
Say you have a file called db.properties in src/main/java/resources/com.stackoverlow (the location doesn't matter) with the following content
database.url=#url#
Note that the # surrounding the url text is required.
You can then define this in your build.gradle file.
processResources {
filter ReplaceTokens, tokens: [
"url": "https://stackoverflow.com"
]
}
When you build your code, this would replace #url# with https://stackoverflow.com.
If you are only interested in applying this rule to a specific file, you can add a filesMatching
processResources {
filesMatching('**/db.properties') {
filter ReplaceTokens, tokens: [
"url": "https://stackoverflow.com"
]
}
}
See gradle doc for more explanation