java - gradle build: repo1.maven.org: unknown error -

i have spring-boot app able start server in eclipse. however, when goto terminal , gradle compile, here console log getting:

    failure: build failed exception.  * went wrong: problem occurred configuring root project 'springbootrest'. > not resolve dependencies configuration ':classpath'.    > not resolve org.springframework.boot:spring-boot-gradle-plugin:1.2.5.release.      required by:          :springbootrest:unspecified       > not resolve org.springframework.boot:spring-boot-gradle-plugin:1.2.5.release.          > not resource 'https://repo1.maven.org/maven2/org/springframework/boot/spring-boot-gradle-plugin/1.2.5.release/spring-boot-gradle-plugin-1.2.5.release.pom'.             > not head 'https://repo1.maven.org/maven2/org/springframework/boot/spring-boot-gradle-plugin/1.2.5.release/spring-boot-gradle-plugin-1.2.5.release.pom'.                > repo1.maven.org: unknown error  * try: run --stacktrace option stack trace. run --info or --debug option more log output.  build failed 

i not entirely sure why happening: seems having issues proxy server, if wget can files under repo1.maven...

for reference, build.gradle:

buildscript {     repositories {         mavencentral()     }     dependencies {         classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.5.release")     } } // same in .bash_profile systemprop.http.proxyhost='my proxy server' systemprop.http.proxyport='my proxy port'   apply plugin: 'java' apply plugin: 'eclipse' apply plugin: 'idea' apply plugin: 'maven' apply plugin: 'spring-boot'  group = 'lookupgroup'  jar {     basename = 'lookupservice'     version =  '0.1.0' }  sourcecompatibility = 1.8 targetcompatibility = 1.8  repositories {     mavencentral() }  dependencies {     compile 'org.springframework.boot:spring-boot-gradle-plugin:1.2.5.release'     compile("org.springframework.boot:spring-boot-starter-web")     compile("org.springframework.boot:spring-boot-starter-actuator")     testcompile("org.springframework.boot:spring-boot-starter-test")     testcompile("junit:junit") }  task wrapper(type: wrapper) {     gradleversion = '2.3' } 

any idea why can't build?

proxy properties should configured in gradle.properties file stated in docs.