从类文件中读取一行代码
给定一个 StackTraceElement.getLineNumber() ，有没有办法从编译的类文件中读取该行的内容？即使可以匹配该行，类文件的内容是否会被编译器“混淆”？
例如，如果我有：
public void myMethod () {
MyObj m = new MyObj (); // can I reconstruct this line as String?
}
Given a StackTraceElement.getLineNumber(), is there a way to read the content of this line from a compiled class file? And even if it is possible to match the line, would the content of the class file will be "obfuscated" by the compiler?
For example if I had:
public void myMethod () {
MyObj m = new MyObj (); // can I reconstruct this line as String?
}
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源代码不包含在编译的类文件中，该类文件包含字节码；所以不，仅从类文件工作，您无法重建该行代码。当然，可以反编译 Java 字节码，并且一个足够完善的反编译器可能会或多或少地重建该代码行，但您必须有一个像样的反编译器。最终结果可能看起来很像也可能不太像原始源代码，具体取决于优化等。
The source code is not contained by the compiled class file, which contains bytecode; so no, working only from the class file you can't reconstruct that line of code. It's possible to de-compile Java bytecode, of course, and a sufficiently well-built decompiler might reconstruct that line of code to a greater or lesser extent, but you'd have to have a decent decompiler. The end results may or may not look much like the original source code, depending on optimisations and such.
您可以将源文件包含到您的 war / jar 文件中，您可以将其作为文件读取。字节码仅包含行号，而不包含实际代码
you can include the source file into your war / jar file which you can read as a file. The bytecode only contains the line number not the actual code
您可以从类文件 (Foo.class) 中检索字节码指令，但不能检索表示源代码的字符串。但是，给定源文件和行号，您可以使用标准文件读取技术从源文件 (Foo.java) 中读取该行。
要了解 .class 文件中包含的信息类型，请查看
javap工具。我想从技术上讲，您可以对编译到该类的源代码做出最好的猜测，或者对其运行反编译器，但行号不会完全匹配，格式会完全不同，也许最重要的是，不会有注释或使用源保留级别的注释。You could retrieve the bytecode instructions from the class file (Foo.class), but not the String that represents the source code. However, given a source file and a line number, you could instead read the line from the source file (Foo.java), using standard file reading techniques.
To get an idea of the kind of information contained in a .class file, check out the
javaptool. I suppose technically you could make a best guess at the source that compiled to that class, or run a decompiler on it, but line numbers won't match exactly, formatting would be totally different, and perhaps crucially, there would be no comments or annotations using source retention level.