[Java] Adapt to Java 9/9+ automatic module system
- 主要語言
- Java
- 星號
- 94
- 分支
- 152
- 平均合併
- 3 天 16 小時
- 30 天內合併 PR
- 11
描述
In Java 9/9+, within following module-info.java definition the build will fail by error:
```Java
module my.app {
exports my.app;
requires arrow.memory.core;
requires arrow.memory.unsafe;
}
```
The error:
> java: the unnamed module reads package org.apache.arrow.memory from both arrow.memory.core and arrow.memory.unsafe
It seems that JPMS requires a package to be read from at most one individual module. Ref: http://openjdk.java.net/projects/jigsaw/spec/sotms/#the-module-path. If so what we may have to do is to conduct a code clean up for our maven modules to make sure we don't populate codes in the same package into different libraries.
Also, as a more standardized practice, it's might be an option to put entries with name **Automatic-Module-Name** into manifest files to tell automatic module system to generate predefined module names rather than parsing from jar file name. Ref: https://docs.oracle.com/javase/9/docs/api/java/lang/module/ModuleFinder.html#automatic-modules
Note that it's not a goal for this topic to migrate to Java 9/9+.
**Reporter**: [Hongze Zhang](https://issues.apache.org/jira/browse/ARROW-12905) / @zhztheplayer
**Note**: *This issue was originally created as [ARROW-12905](https://issues.apache.org/jira/browse/ARROW-12905). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*
貢獻指南
研究方向
Start with the module-info.java example and the Maven modules that provide org.apache.arrow.memory, then review the linked migration documentation and JPMS references. Check how packages are split between arrow.memory.core and arrow.memory.unsafe and how manifest files are produced. Done means the duplicate-package failure is addressed and automatic module names are defined where appropriate without migrating the project to Java 9+.
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評估
- 技術堆疊
- java
- 領域
- build-system
- Issue 類型
- 重構
- 難度
- 5/5
- 預估耗時
- 一週以上
- 活躍度
- 停滯
- 描述清晰度
- 需要釐清
- 新手友好度
- 20/100