Java单独的System.out用于单独的类路径 [英] Java separate System.out for separate Classpath

问题描述

我正在开发一个需要调用某些Jenkins实例的应用程序，为此，我正在使用jenkins-cli .jar
我可能使用命令行调用jar来轻松提取其输出.然后，我需要自己解析异常.
为了正确处理异常，我现在通过反射调用jar的主要方法:

I am developing an application which needs to call some Jenkins instances, to do this I am using the jenkins-cli .jar
I could be calling the jar using the commandline to easily extract its output. Then however I need to parse exceptions myself.
To properly handle exceptions I am now invoking the main method of the jar via reflection:

URLClassLoader jenkinsClassloader = new URLClassLoader(new URL[]{"UrlToJenkins-Cli.jar"}, getClass().getClassLoader());
Class<?> jenkinsCli = Class.forName ("hudson.cli.CLI", false, jenkinsClassloader);
Method mainMethod = jenkinsCli.getDeclaredMethod("main", String[].class);
mainMethod.invoke (null, (Object) commandArray);

但是现在我需要以某种方式将jar打印的输出输出到System.out
我知道我可以使用System.setOut().那里的问题是我有其他线程同时记录. 我阅读了这里 System.out是特定于类加载器的，但是我找不到关于此的任何其他信息.
有人知道一种在不受到其他线程干扰的情况下获取jar的stdout的方法吗?

But now I need to somehow get the output the jar prints to System.out
I know I can use System.setOut(). The problem there is that I have other threads logging simultaniously. I read here that System.out is classloader specific, but I couldn't find any additional information about this.
Does someone know a way to get the stdout of the jar without it being interfered with from other threads?

推荐答案

一种可能是创建扩展 ThreadLocal 私有属性，可用于告诉它对于当前线程是否应截取文本.

One possibility would be to create a custom class extending PrintStream, that would simply pass whatever is passed to it to another PrintStream, then wrap that around System.out, via System.setOut(); the custom class could have a ThreadLocal private attribute that could be used to tell it if, for the current thread, the text should be intercepted.

这不是最优雅的解决方案，但是如果找不到其他选择，则可能是一个很好的解决方案.

Not the most elegant of solutions, but could be a good fallback if no alternative is found.

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