1、下载jdk6
https://support.apple.com/kb/DL1572?locale=zh_CN
macos10.15已经存在jdk7、8版本，安装过程提示：已经安装过高版本。
2、打开“脚本编辑器”，输入代码
set theDMG to choose file with prompt "Please select javaforosx.dmg:" of type {"dmg"}
do shell script "hdiutil mount " & quoted form of POSIX path of theDMG
do shell script "pkgutil --expand /Volumes/Java\\ for\\ macOS\\ 2017-001/JavaForOSX.pkg ~/tmp"
do shell script "hdiutil unmount /Volumes/Java\\ for\\ macOS\\ 2017-001/"
do shell script "sed -i '' 's/return false/return true/g' ~/tmp/Distribution"
do shell script "pkgutil --flatten ~/tmp ~/Desktop/Java.pkg"
do shell script "rm -rf ~/tmp"
display dialog "Modified Java.pkg saved on desktop" buttons {"Ok"}
3、执行脚本，在弹出窗口中选择下载目录中JavaForOSX.dmg，在桌面会生成一个新的安装包java.pkg
4、双击打开pkg文件，完成程序安装，默认安装路径
/Library/Java/JavaVirtualMachines/1.6.0.jdk
5、idea新建maven工程，pom文件如下
<name>SpringBoot</name>
<description>Demo project for Spring Boot jdk1.6</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.5.RELEASE</version>
<relativePath/>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<maven.compiler.source>1.6</maven.compiler.source>
<maven.compiler.target>1.6</maven.compiler.target>
<java.version>1.6</java.version>
<tomcat.version>7.0.79</tomcat.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</pluginManagement>
<defaultGoal>compile</defaultGoal>
</build>
6、启动报错，修改模块中maven配置
importing： jdk1.7
runner：jre1.6
7、modules
project setting: SDK 1.6
platforms setting: SDK 1.6
