我在eclipse IDE中也遇到了同样的问题。我阅读了这个问题的所有答案，并尝试了几乎所有提到的设置，但运气不好。

所以，我尝试改变项目的运行时库，以前它是JRE - Java SE 1.8

我尝试将JRE更改为JDK，它为我工作:

从JRE切换到JDK的步骤如下:

Right click on project Click Properties -> Java Build Path Select tab - "Libraries" Click on "Add Library" button. "Add Library" window will open Select "JRE System Library" -> Click Next button Select "Alternate JRE" Click on Installed JRE button In New window click on "Add". This will open another window "Add JRE". Select "Standard VM". Click Next. Click on Directory button. Choose path of your "JDK" installation directory and click ok. Then Click Finish. Now check on newly added "JDK" Delete all other installed JRE's from the list(Optional) Apply-> OK Select "JDK from alternate JRE dropdown and Click on "Finish" Now from the list depicted below remove JRE instance Click Apply -> OK

你完蛋了!!

这里有详细的解释:

https://github.com/spring-projects/spring-ide/issues/78

只是为了将来参考，这是答案的相关部分(忽略引用Spring Boot应用程序的事实，在许多其他情况下行为是相同的):

Whenever you set a breakpoint in Eclipse/STS, the IDE tries to set the breakpoint in the VM if you launch an app. That is what happens in your case when you run the boot app in debug mode. For each class that gets loaded into the JVM, the IDE checks whether it needs to set a breakpoint or not. If it decides to set the breakpoint, the tries to do so (using the information from the breakpoint definition in the IDE, including its line number, since you usually set line breakpoints on a source file at a given line). This decision (whether to set the breakpoint on a given loaded class or not) checks the types that you set the breakpoint on, enclosing types, and inner classes. This makes sure that breakpoints for inner classes (even anonymous inner classes) are set to the JVM (and are not ignored). Spring Boot generates an inner class for your controller at runtime (this is the CGLIB generated inner class that appears in the error message). When the JVM loads that class, it tries to set the line number breakpoint of the enclosing type (for this inner class). Since the generated inner class doesn't have any line number information (it doesn't need to have line number information), setting the breakpoint fails for this inner class with the mentioned error message. When the IDE loads the enclosing type (your controller class itself), it also tries to set the line breakpoint and succeeds with that. This is visualized with the check marker on the breakpoint marker. Therefore you can safely ignore the error message that shows up. To avoid this error message to show up, you can go to the preferences (Java -> Debug) and disable "Warn when unable to install breakpoint due to missing line number attributes".

确保运行时的主类所在的项目与包含断点的类所在的项目相同。如果不是，请确保两个项目都在运行配置的类路径中，并且出现在任何jar和类文件夹之前。

我在一个特定的项目中遇到了同样的问题，我一直试图重置窗口中的行号属性->首选项…然后我意识到每个项目都有自己的行号属性设置。右键单击项目，进入属性，选择JavaCompiler，并选中“添加行号属性…”

我在Spring MVC + Maven项目上也有类似的问题;并且花了2个小时试图弄清楚为什么目标文件夹没有更新包含行信息的类。

我建议您清理所有内容，并确保在继续进行任何构建之前从文件夹中删除所有类。

确保在项目的属性> Java编译器有“添加行号属性生成类字段(由调试器使用)选择。 清洁所有项目。(菜单>项目>清洁…)确保目标文件夹为空。 构建项目(菜单>项目>构建项目) 确保在目标目录中生成了新类。 运行调试;如果在WebServer上运行，请确保在“调试”模式下运行web服务器。

如果有疑问——编译后的.class文件是否包含行号——在Eclipse中打开.class文件。Eclipse将反编译文件并告诉您行号是否存在。

在eclipse菜单中，进入“窗口->首选项->Java->编译器” 取消标记复选框“添加行号属性…” 单击“应用”->是 标记复选框“添加行号属性…” 再次申请。 愉快调试