/*
Licensed?to?the?Apache?Software?Foundation?（ASF）?under?one
or?more?contributor?license?agreements.??See?the?NOTICE?file
distributed?with?this?work?for?additional?information
regarding?copyright?ownership.??The?ASF?licenses?this?file
to?you?under?the?Apache?License?Version?2.0?（the
“License“）;?you?may?not?use?this?file?except?in?compliance
with?the?License.??You?may?obtain?a?copy?of?the?License?at

??https://www.apache.org/licenses/LICENSE-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.
*/

import?java.io.File;
import?java.io.FileInputStream;
import?java.io.FileOutputStream;
import?java.io.IOException;
import?java.net.URL;
import?java.nio.channels.Channels;
import?java.nio.channels.ReadableByteChannel;
import?java.util.Properties;

public?class?MavenWrapperDownloader?{

????/**
?????*?Default?URL?to?download?the?maven-wrapper.jar?from?if?no?‘downloadUrl‘?is?provided.
?????*/
????private?static?final?String?DEFAULT_DOWNLOAD_URL?=
????????????“https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar“;

????/**
?????*?Path?to?the?maven-wrapper.properties?file?which?might?contain?a?downloadUrl?property?to
?????*?use?instead?of?the?default?one.
?????*/
????private?static?final?String?MAVEN_WRAPPER_PROPERTIES_PATH?=
????????????“.mvn/wrapper/maven-wrapper.properties“;

????/**
?????*?Path?where?the?maven-wrapper.jar?will?be?saved?to.
?????*/
????private?static?final?String?MAVEN_WRAPPER_JAR_PATH?=
????????????“.mvn/wrapper/maven-wrapper.jar“;

????/**
?????*?Name?of?the?property?which?should?be?used?to?override?the?default?download?url?for?the?wrapper.
?????*/
????private?static?final?String?PROPERTY_NAME_WRAPPER_URL?=?“wrapperUrl“;

????public?static?void?main（String?args[]）?{
????????System.out.println（“-?Downloader?started“）;
????????File?baseDirectory?=?new?File（args[0]）;
????????System.out.println（“-?Using?base?directory:?“?+?baseDirectory.getAbsolutePath（））;

????????//?If?the?maven-wrapper.properties?exists?read?it?and?check?if?it?contains?a?custom
????????//?wrapperUrl?parameter.
????????File?mavenWrapperPropertyFile?=?new?File（baseDirectory?MAVEN_WRAPPER_PROPERTIES_PATH）;
????????String?url?=?DEFAULT_DOWNLOAD_URL;
????????if?（mavenWrapperPropertyFile.exists（））?{
????????????FileInputStream?mavenWrapperPropertyFileInputStream?=?null;
????????????try?{
????????????????mavenWrapperPropertyFileInputStream?=?new?FileInputStream（mavenWrapperPropertyFile）;
????????????????Properties?mavenWrapperProperties?=?new?Properties（）;
????????????????mavenWrapperProperties.load（mavenWrapperPropertyFileInputStream）;
????????????????url?=?mavenWrapperProperties.getProperty（PROPERTY_NAME_WRAPPER_URL?url）;
????????????}?catch?（IOException?e）?{
????????????????Syst