This is a simple download task for Gradle. It displays progress information just as Gradle does when it retrieves an artifact from a repository.
The plugin has been sucessfully tested with Gradle 1.0 up to 4.8. It should work with newer versions as well.
plugins {
id "de.undercouch.download" version "3.4.3"
}
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'de.undercouch:gradle-download-task:3.4.3'
}
}
apply plugin: 'de.undercouch.download'
After you applied the plugin configuration (see above) you can use the Download
task as follows:
task downloadFile(type: Download) {
src 'http://www.example.com/index.html'
dest buildDir
}
By default, the plugin always performs a download even if the destination file
already exists. If you want to prevent files from being downloaded again, use
the overwrite
flag (see description below).
task downloadFile(type: Download) {
src 'http://www.example.com/index.html'
dest buildDir
overwrite false
}
As an alternative to the Download
task, you may also use the download
extension to retrieve a file anywhere in your build script:
task myTask << {
//do something ...
//... then download a file
download {
src 'http://www.example.com/index.html'
dest buildDir
overwrite false
}
//... do something else
}
task downloadFile(type: Download) {
src 'http://www.example.com/index.html'
dest buildDir
onlyIfModified true
}
Note that this feature depends on the server and whether it supports the
If-Modified-Since
request header and if it provides a Last-Modified
timestamp in its response.
task downloadMultipleFiles(type: Download) {
src([
'http://www.example.com/index.html',
'http://www.example.com/test.html'
])
dest buildDir
}
Please note that you have to specify a directory as destination if you download multiple files. Otherwise the plugin will fail.
If you want to download all files from a directory and the server provides a simple directory listing you can use the following code:
task downloadDirectory {
def dir = 'http://central.maven.org/maven2/de/undercouch/gradle-download-task/1.0/'
def urlLister = new org.apache.ivy.util.url.ApacheURLLister()
def files = urlLister.listFiles(new URL(dir))
download {
src files
dest buildDir
}
}
To download and unpack a ZIP file you can combine the download task plugin with Gradle's built-in support for ZIP files:
task downloadZipFile(type: Download) {
src 'https://github.com/michel-kraemer/gradle-download-task/archive/1.0.zip'
dest new File(buildDir, '1.0.zip')
}
task downloadAndUnzipFile(dependsOn: downloadZipFile, type: Copy) {
from zipTree(downloadZipFile.dest)
into buildDir
}
Please have a look at the examples
directory for more code samples. You can
also read my blog post about
common recipes for gradle-download-task.
The download task and the extension support the following properties.
- src
- The URL from which to retrieve the file. Can be a list of URLs if multiple files shoud be downloaded. (required)
- dest
- The file or directory where to store the file (required)
- quiet
true
if progress information should not be displayed (default:false
)- overwrite
true
if existing files should be overwritten (default:true
)- onlyIfModified (alias: onlyIfNewer)
true
if the file should only be downloaded if it has been modified on the server since the last download (default:false
)
Tip! You may provide Groovy Closures to the src
and dest
properties to calculate their value at runtime.
- acceptAnyCertificate
true
if HTTPS certificate verification errors should be ignored and any certificate (even an invalid one) should be accepted. (default:false
)- compress
true
if compression should be used during download (default:true
)- header
- The name and value of a request header to set when making the download request (optional)
- headers
- A map of request headers to set when making the download request (optional)
- timeout
- The maximum number of milliseconds to wait until a connection is established or until the
server returns data. A value of
0
(zero) means infinite timeout. A negative value is interpreted as undefined. (default:-1
)
- username
- The username for
Basic
orDigest
authentication (optional) - password
- The password for
Basic
orDigest
authentication (optional) - credentials
- The credentials to use for authentication. This property is an alternative to
username
andpassword
. The value is expected to be an instance of Credentials. (optional) - authScheme
- The authentication scheme to use. Either a string (valid values are
Basic
andDigest
) or an instance of AuthScheme. If credentials are configured (either throughusername
andpassword
or throughcredentials
) the default value of this property will beBasic
. Otherwise this property has no default value. (optional)
- downloadTaskDir
- The directory where the plugin stores information that should persist between builds. It will only be created if necessary. (default:
${buildDir}/download-task
) - tempAndMove
true
if the file should be downloaded to a temporary location and, upon successful execution, moved to the final location. Ifoverwrite
is set tofalse
, this flag is useful to avoid partially downloaded files if Gradle is forcefully closed or the system crashes. Note that the plugin always deletes partial downloads on connection errors, regardless of the value of this flag. The default temporary location can be configured with thedownloadTaskDir
property. (default:false
)- useETag
- Use this flag in combination with
onlyIfModified
. If both flags aretrue
the plugin will check a file's timestamp as well as its entity tag (ETag) and only download it if it has been modified on the server since the last download. The plugin can differentiate between strong and weak ETags. Possible values are:false
(default)- Do not use the ETag
true
- Use the ETag but display a warning if it is weak
"all"
- Use the ETag and do not display a warning if it is weak
"strongOnly"
- Only use the ETag if it is strong
- cachedETagsFile
- The location of the file that keeps entity tags (ETags) received
from the server. (default:
${downloadTaskDir}/etags.json
) - requestInterceptor
- An instance of HttpRequestInterceptor. Can be used to intercept and modify outgoing HTTP requests before they are sent to the server. (optional)
- responseInterceptor
- An instance of HttpResponseInterceptor. Can be used to intercept and manipulate HTTP responses from the server before they are handled by the plugin. (optional)
The plugin also provides a Verify
task that can be used to check the integrity
of a downloaded file by calculating its checksum and comparing it to a
pre-defined value. The task succeeds if the file's checksum equals the
given value and fails if it doesn't.
Use the task as follows:
task verifyFile(type: Verify) {
src new File(buildDir, 'file.ext')
algorithm 'MD5'
checksum 'ce114e4501d2f4e2dcea3e17b546f339'
}
You can combine the download task and the verify task as follows:
task downloadFile(type: Download) {
src 'http://www.example.com/index.html'
dest buildDir
}
task verifyFile(type: Verify, dependsOn: downloadFile) {
src new File(buildDir, 'index.html')
algorithm 'MD5'
checksum '09b9c392dc1f6e914cea287cb6be34b0'
}
The verify task supports the following properties:
- src
- The file to verify (required)
- checksum
- The actual checksum to verify against (required)
- algorithm
- The algorithm to use to compute the checksum. See the
list of algorithm names
for more information. (default:
MD5
)
You can configure a proxy server by setting standard JVM system properties. The plugin uses the same system properties as Gradle. You can set them in the build script directly. For example, the proxy host can be set as follows:
System.setProperty("http.proxyHost", "www.somehost.org");
Alternatively, you can set the properties in a gradle.properties
file like
this:
systemProp.http.proxyHost=www.somehost.org
systemProp.http.proxyPort=8080
systemProp.http.proxyUser=userid
systemProp.http.proxyPassword=password
systemProp.http.nonProxyHosts=*.nonproxyrepos.com|localhost
Put this file in your project's root directory or in your Gradle home directory.
HTTPS is also supported:
systemProp.https.proxyHost=www.somehost.org
systemProp.https.proxyPort=8080
systemProp.https.proxyUser=userid
systemProp.https.proxyPassword=password
systemProp.https.nonProxyHosts=*.nonproxyrepos.com|localhost
The plugin is licensed under the Apache License, Version 2.0.
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.