1.在build.gradle添加脚本指定编译堆内存

• 如果在整个工程中生效，则在build.gradle中增加如下配置：

android {..............      dexOptions {            incremental true            javaMaxHeapSize "4g"        }...............}

• 如果只在单元测试的时候生效，则在build.gradle中增加如下配置：
  android {..............    testOptions {        android.dexOptions {            incremental true            javaMaxHeapSize "4g"        }    }...............}
  2.添加gradle的配置文件指定堆内存
  也可以在gradle.properties中修改build环境中的jvmargs参数大小：
  在项目根目录新建gradle.properties文件内容为：
• ## Project-wide Gradle settings.## For more details on how to configure your build environment visit# http://www.gradle.org/docs/current/userguide/build_environment.html## Specifies the JVM arguments used for the daemon process.# The setting is particularly useful for tweaking memory settings.# Default value: -Xmx10248m -XX:MaxPermSize=256m# org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8## When configured, Gradle will run in incubating parallel mode.# This option should only be used with decoupled projects. More details, visit# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects# org.gradle.parallel=true#Mon Jun 13 14:58:46 CST 2016org.gradle.daemon=trueorg.gradle.parallel=trueorg.gradle.jvmargs=-Xmx5120m