elasticsearch-hadoop.jar 6.8版本编译异常

## 背景

重新编译 elasticsearch-hadoop 包；

GitHub - elastic/elasticsearch-hadoop at 6.8

编译 7.17 版本时很正常，注意设置下环境变量就好，JAVA8_HOME/....

编译 6.8 版本时（要求jdk8 / jdk9），出现异常

1. Could not resolve org.springframework.build.gradle:propdeps-plugin:0.0.7.

2. Could not resolve cascading:cascading-local:2.6.3.

3. Could not resolve org.elasticsearch.gradle:build-tools:6.8.24-SNAPSHOT

4. Could not resolve cascading:cascading-hadoop:2.6.3.

## 分析（尝试逐个解决）

1. gradle 仓库修改

    // ali库 解决 Could not resolve org.springframework.build.gradle:propdeps-plugin:0.0.7.maven{ url 'https://maven.aliyun.com/repository/central'}maven{ url 'https://maven.aliyun.com/repository/public' }maven{ url 'https://maven.aliyun.com/repository/google'}maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}maven{ url 'https://maven.aliyun.com/repository/spring'}maven{ url 'https://maven.aliyun.com/repository/spring-plugin'}maven{ url 'https://maven.aliyun.com/mvn/guide'}maven{ url 'https://maven.aliyun.com/repository/apache-snapshots'}

2. esh-version.properties 修改

6.8.24-SNAPSHOT -> 6.8.23

3. cascading-local 这个包始终无法获取

## 最终解决

本质原因有2个，一个是 repo.spring.io 改造成需要验证了，不验证会有401；另一个是http://conjars.org/repo 已经失效了，需要替换；

所以前面修改的全部回滚，完整解决方案如下：

1. 处理 propdeps-plugin 包，增加阿里云的库

    // ali库 propdeps-pluginmaven{ url 'https://maven.aliyun.com/repository/central'}maven{ url 'https://maven.aliyun.com/repository/public' }maven{ url 'https://maven.aliyun.com/repository/google'}maven{ url 'https://maven.aliyun.com/repository/gradle-plugin'}maven{ url 'https://maven.aliyun.com/repository/spring'}maven{ url 'https://maven.aliyun.com/repository/spring-plugin'}maven{ url 'https://maven.aliyun.com/mvn/guide'}maven{ url 'https://maven.aliyun.com/repository/apache-snapshots'}

2. 修改 buildSrc/src/main/groovy/org/elasticsearch/hadoop/gradle/BuildPlugin.groovy

全部的 http://conjars.org/repo 或者 https://conjars.org/repo替换成 https://conjars.wensel.net/repo

## 参考：

1. Notice of Permissions Changes to repo.spring.io, January 2023

2. https://segmentfault.com/q/1010000043853512

3. spring源码编译问题解决1，Received status code 401 from server问题，not found问题，更换阿里云镜像_received status code 401 from server:-CSDN博客

 4. https://github.com/elastic/elasticsearch-hadoop/issues/984

 5. How to build a plugin for a not yet released version? - Elasticsearch - Discuss the Elastic Stack

6. conjars.org: Connection timed out_http://conjars.org/repo 地址失效-CSDN博客