设置idea的ant工具的代理

现在主流的项目都使用maven来构建了，还在使用ant的项目应该是比较老旧了，现在因为需要调试zookeeper的源码，所以需要用到ant。使用时遇到点问题，借此记录一下爬坑过程。

1. 问题复现

IDE使用的是Intellij idea，因此使用的是它自带的ant插件，导入zookeeper源码，点开ant界面，Run Target->compile，然后就出现如下错误：

Error getting https://repo1.maven.org/maven2/org/apache/ivy/ivy/2.4.0/ivy-2.4.0.jar to C:workspacezookeeper-3.4.13srcjavalibivy-2.4.0.jar
C:workspacezookeeper-3.4.13build.xml:392: java.net.ConnectException: Connection timed out: connect

zookeeper需要用ivy.jar，下载ivy.jar失败。
因为使用的是公司网络，看到这个错误，第一反应就是没有配置代理。另外，IDEA的系统设置里面，HTTP代理已设置，执行ant并未生效，说明它没去读IDEA的配置。于是，查看ant官网https://ant.apache.org/manual/index.html，如何配置代理。

ant官网提供了几种设置代理的方式，针对IDEA的ant插件，比较合适的是手动设置JVM参数。增加如下参数即可：

-Dhttp.proxyHost=proxy -Dhttp.proxyPort=8080

现在问题来了，上面的参数配置到哪里呢？

2. 设置代理

一番摸索，发现在ant面板上，有一个 Properties 的标签，点击该标签，会弹出配置参数的界面，也可右键ant面板上的任意target命令，如下：

上图中的各个参数，都可在IDEA官网中找到解释(点击上图中左下角的问号图标，即可打开)。

通过官网介绍，符合条件的应该就是 Ant command line，点击 Execution 标签，可看到如下界面：

注意文本框下面的那行小字 Use “-J” prefix to specify JVM arguments ，这个在官网的说明里面没有描述，所以我看到这个时有点疑惑，到底该如何添加呢？一顿瞎操作之后，都没蒙对组合方式。
比如：-Jhttps.proxyHost=1.1.1.1，执行Run，报错如下：

Error: Could not find or load main class https.proxyHost=1.1.1.1


Ant build completed with one error and no warnings in 0s at 2022/3/24 15:14

不想瞎猜了，同时也想搞清楚它是如何解析参数的，所以最后去下载了IDEA的源码。
IDEA的源码很大，又该从哪里入手呢？这里就通过搜关键字来找源码了，简单粗暴一点就是直接搜 Ant 关键字，但这样搜出来的源文件还是比较多，需要挨个确认。我们可以再使用精确一点关键字，这个关键字又是什么呢？

留意一下Ant build的时候的输出信息(输出到IDEA的 Messages 窗口里)，如下：

"C:Program FilesAdoptOpenJDKjdk-8.0.292.10-hotspotbinjava.exe
 -Xmx512m -Xss2m
 -Dant.home=C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libant" "
 -Dant.library.dir=C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlib" 
 -Dfile.encoding=UTF-8 -classpath "C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-antlr.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-bcel.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-bsf.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-log4j.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-oro.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-regexp.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-resolver.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-xalan2.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-commons-logging.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-commons-net.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jai.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-javamail.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jdepend.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jmf.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jsch.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junit.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junit4.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junitlauncher.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-launcher.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-netrexx.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-swing.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-testutil.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-xz.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant.jar;C:Program FilesAdoptOpenJDKjdk-8.0.292.10-hotspotlibtools.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libidea_rt.jar" com.intellij.rt.ant.execution.AntMain2 -logger com.intellij.rt.ant.execution.IdeaAntLogger2 -inputhandler com.intellij.rt.ant.execution.IdeaInputHandler -buildfile C:workspacezookeeper-3.4.13build.xml compile
build.xml
init
ivy-download
Getting: https://repo1.maven.org/maven2/org/apache/ivy/ivy/2.4.0/ivy-2.4.0.jar
To: C:workspacezookeeper-3.4.13srcjavalibivy-2.4.0.jar

通过上述日志，可以看到，Ant build 的时候，传入了 Ant 相关的JVM参数。我们在文本框输入的http代理，最终也会在该命令行里面输出。因此，通过这些参数来定位源码，会大幅缩减源码文件。

上图就是搜出来的结果，共三个源文件。从名字和相关代码来看，AntCommandLineBuilder 比较像是所用到的源码(没有进一步跟踪，所以，不能确定)。
同时，为了保证正确性，对比了 AntCommandLineBuilder 和 AntArtifactBuildTaskProvider 两个文件，针对 -J 参数都做了相同的解析。源码如下：

    final String additionalParams = AntBuildFileImpl.ANT_COMMAND_LINE_PARAMETERS.get(container);
    if (additionalParams != null) {
      for (String param : ParametersList.parse(additionalParams)) {
        if (param.startsWith("-J")) {
          final String cutParam = param.substring("-J".length());
          if (cutParam.length() > 0) {
            vmParametersList.add(cutParam);
          }
        }
        else {
          programParameters.add(param);
        }
      }
    }

由上述代码可以看到，-J 前缀会被截取丢掉，只读取后面的字符串。所以，下面可以放心大胆的给出结论了。
输入参数格式如下：

-J-Dhttps.proxyHost=1.1.1.1 -J-Dhttps.proxyPort=8080

-J 参数之间使用空格隔开，这个在IDEA官网文档也有提到。

注意：上面传入的是 https 的代理，因为maven库的url使用的是 https ，如果传入 http 的代理，则会报连接超时的错误(Connection timed out: connect)，和开始提到的错误一样。

3. 重新运行

代理设置完成之后，重新Run target，可看到Ant Build信息里面，命令行已经包含了刚才设置的代理，见下：

"C:Program FilesAdoptOpenJDKjdk-8.0.292.10-hotspotbinjava.exe"  
 -Dhttps.proxyHost=1.1.1.1
 -Dhttps.proxyPort=8080
 -Xmx512m -Xss2m
 -Dant.home=C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libant
 -Dant.library.dir=C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlib
 -Dfile.encoding=UTF-8 -classpath "C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-antlr.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-bcel.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-bsf.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-log4j.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-oro.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-regexp.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-resolver.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-apache-xalan2.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-commons-logging.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-commons-net.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jai.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-javamail.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jdepend.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jmf.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-jsch.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junit.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junit4.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-junitlauncher.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-launcher.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-netrexx.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-swing.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-testutil.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant-xz.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libantlibant.jar;C:Program FilesAdoptOpenJDKjdk-8.0.292.10-hotspotlibtools.jar;C:Program FilesJetBrainsIntelliJ IDEA Community Edition 2021.1.3libidea_rt.jar" com.intellij.rt.ant.execution.AntMain2 -logger com.intellij.rt.ant.execution.IdeaAntLogger2 -inputhandler com.intellij.rt.ant.execution.IdeaInputHandler -buildfile C:workspacezookeeper-3.4.13build.xml compile
build.xml
init
ivy-download

ivy 下载成功，说明代理设置生效。

4. 总结

编译过程中，老是会遇到各种各样的问题。但仔细查看错误信息，会发现大多问题都体现在日志里面。下载源码编译的时候，尽量先阅读官网的相关说明，通常官网都会明确告知需要依赖哪些资源库等信息，这样可以减少错误的发生。遇到问题时，搜索的关键字很重要，关键字不准确，那么显示的结果也就鱼龙混杂，此时需要带着疑问去尝试，可以排除很多不正确的方案。

设置idea的ant工具的代理

Java相关栏目本月热门文章