java 将 System.out.println 重定向到 Log4J，同时保留类名信息
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/5712764/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Redirect System.out.println to Log4J, while keeping class name information
提问by David Parks
I have some libraries that are calling System.out.println on me, I'd like to redirect them through log4j or commons logging. But in particular I'd like to keep the fully-qualified-classname so I know what component generated the logs.
我有一些正在调用 System.out.println 的库，我想通过 log4j 或 commons 日志记录重定向它们。但特别是我想保留完全限定的类名，以便我知道生成日志的组件。
Is there a nice, orderly way to accomplish this?
有没有一种好的、有序的方法来实现这一点？
UPDATE: After accomplishing this I posted the code here:
http://www.bukisa.com/articles/487009_java-how-to-redirect-stderr-and-stdout-to-commons-logging-with-the-calling-class
更新：完成此操作后，我在此处发布了代码：http :
//www.bukisa.com/articles/487009_java-how-to-redirect-stderr-and-stdout-to-commons-logging-with-the-calling-class
回答by Jon Skeet
The only way I can think of would be to write your own PrintStreamimplementation which created a stack trace when the printlnmethod was called, in order to work out the class name. It would be pretty horrible, but it should work... proof of concept sample code:
我能想到的唯一方法是编写自己的PrintStream实现，在调用println方法时创建堆栈跟踪，以便计算出类名。这将是非常可怕的，但它应该可以工作......概念示例代码证明：
import java.io.*;
class TracingPrintStream extends PrintStream {
public TracingPrintStream(PrintStream original) {
super(original);
}
// You'd want to override other methods too, of course.
@Override
public void println(String line) {
StackTraceElement[] stack = Thread.currentThread().getStackTrace();
// Element 0 is getStackTrace
// Element 1 is println
// Element 2 is the caller
StackTraceElement caller = stack[2];
super.println(caller.getClassName() + ": " + line);
}
}
public class Test {
public static void main(String[] args) throws Exception {
System.setOut(new TracingPrintStream(System.out));
System.out.println("Sample line");
}
}
(In your code you would make it log to log4j instead of course... or possibly as well.)
（在您的代码中，您将使其登录到 log4j 而不是当然......或者也可能如此。）
回答by Ralph
If you can modify the source code, then have a look at the Eclipse Plugin Log4E. It provides a function to convert System.out.println into logger statements (and many other cool stuff dealing with logging).
如果您可以修改源代码，请查看Eclipse 插件 Log4E。它提供了一个函数将 System.out.println 转换为记录器语句（以及许多其他处理日志的很酷的东西）。
