用Java来编译调试代码 [英] Compile debug code in or out in Java

问题描述

我希望能够在发布产品时将调试代码（详细的日志记录等）编译出来，但要编译以进行调试。

I would like to be able to have my debug code (verbose logging, etc) compiled out when I make a production release, but compiled in for debugging.

我知道，如果我在常量上分支，编译器将删除该分支，这就是我想要的。所以我有一个类：

I understand that if I branch on a constant, the compiler will remove the branch, which is what I want. So I have a class:

class Debug {
  public static final boolean ON=true;
}

而我的调试代码位于这样的分支中：

and my debug code is inside a branch like this:

if (Debug.ON) {
    // Verbose / expensive logging goes here
}

我的问题是，我如何安排Debug.ON在编译时设置为true或false，而实际上不编辑源文件？

My question is, how do I arrange for Debug.ON to be set to true or false at compile time, short of actually editing the source file?

编辑：请注意，我不关心控制是否显示日志输出-我正在使用java.util.Logging，它可以解决这一问题。 。我更关心编译出昂贵的代码，这些代码正在准备永远不会得到输出的日志消息，或者进行生产模式中不需要的测量。

Note that I am not concerned with controlling whether log output appears or not - I am using java.util.Logging and it can take care of that. I am more concerned with compiling out any expensive code that is preparing log messages which will never get output, or taking measurements that are not needed in production mode.

我想我可能有一个蚂蚁目标，它可以从模板等生成源文件，但这看起来像是黑客。在C ++中，我可以定义可以与-D一起传递的预处理器符号-是否有Java等效项？还是其他更好的方法？

I guess I could have an ant target that makes the source file from a template or something, but it seems like a hack. In C++ I'd be able to define a pre-processor symbol which I could pass in with -D - is there any Java equivalent? Or some other better way?

推荐答案

您可以做的是拥有两个Jar或类文件。

What you can do is have two Jars or class files.

一个包含Debug类，其ON = true，另一个ON = false。

The one contains the Debug class with ON = true and the other ON = false.

然后，根据所需的调试状态进行编译时，应在类/ jar文件上包含DEBUG或在类/ jar文件上包含DEBUG。

Then when you compile depending on what debug state you want you include the DEBUG on class/jar file or the DEBUG off class/jar file.

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