Gradle Download Task

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 4.1. It should work with newer versions as well.

Apply plugin configuration

Gradle 2.1 and higher

plugins {

  id "de.undercouch.download" version "3.3.0" 
}

Gradle 1.x and 2.0

buildscript {

  repositories {

jcenter()
  
}

  dependencies {

classpath 'de.undercouch:gradle-download-task:3.3.0'
  
}
 
}
  apply plugin: 'de.undercouch.download'

Usage

After you applied the plugin configuration (see above) you can use the Download task as follows:

import de.undercouch.gradle.tasks.download.Download  task downloadFile(type: Download) {

  src 'http://www.example.com/index.html'
  dest buildDir 
}

You can 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
  
}

  //... do something else 
}

Examples

Sequentially download a list of files to a directory:

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.

Download task

The download task and the extension support the following properties.

General

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.

Connection

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 time 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)

Authentication

username: The username for Basic or Digest authentication (optional)
password: The password for Basic or Digest authentication (optional)
credentials: The credentials to use for authentication. This property is an alternative to username and password. The value is expected to be an instance of Credentials. (optional)
authScheme: The authentication scheme to use. Either a string (valid values are Basic and Digest) or an instance of AuthScheme. If credentials are configured (either through username and password or through credentials) the default value of this property will be Basic. Otherwise this property has no default value. (optional)

Advanced

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)

Verify task

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:

import de.undercouch.gradle.tasks.download.Verify  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:

import de.undercouch.gradle.tasks.download.Download import de.undercouch.gradle.tasks.download.Verify  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)

Proxy configuration

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

License

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.

gradle-download-task