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".

我在Eclipse 3.4.1中有相同的错误消息，SUN JVM1.6.0_07连接到Tomcat 6.0(在另一台机器上以调试模式运行，SUN JVM1.6.0_16，调试连接正常工作)。

窗口——>首选项——> Java——>编译器——>类文件生成:“添加行号属性生成类文件”被选中。我做了一个干净的重新编译。我取消检查，重新编译，检查，重新编译。我确保项目使用了全局设置。还是一样的信息。

我切换到蚂蚁构建，使用

<javac srcdir="./src/java" destdir="./bin" debug="true">

同样的信息。

我不知道是什么导致了这条消息，为什么它不会消失。尽管这似乎与正在运行的Tomcat调试会话有关:当断开连接时，重新编译可以解决问题。但是在将调试器连接到Tomcat或在连接的调试会话期间设置新的断点时，它又会出现。

然而，事实证明消息是错误的:我确实能够在调试之前和调试期间调试和设置断点(javap -l也显示了行号)。所以请忽略它:)

在调试部署到Tomcat的WAR(由多个Eclipse项目构件构造)时，我遇到了同样的问题。

我正在使用ANT构建脚本构建所有内容。如果这是您正在做的事情，请确保在您获得的每个javac ant任务上设置了debug=true标志。这是我唯一的问题-我希望它能帮助你的问题!

首先，我建议确定问题是与项目相关还是与单个测试文件相关。试着在调试模式下运行任何其他测试文件。

如果问题只适用于一个文件，这可能与自我嘲笑有关(就像我的情况一样)。否则，编译器/构建设置应该被更改。在之前的评论中已经描述过了。

我只是想强调一下。这已经足够我浪费时间在修复项目设置，而这是完全没有必要的:)

If someone is trying to debug Java's source code, then, this is the only solution that worked for me. Most of the above answers talk about setting the Compiler option to generate line numbers.But, if want to debug Java's source code (say java.util.HashMap), then the above options may not work for you. This is because , the project from where you intend to debug the source code is having the Java Build Path --> Library --> JRE System Library pointing to the jre jar instead of the jdk jar. The classes bundled inside jre jar have already been pre-compiled with a specific option, that will not honor the Compiler option settings. Solution, is to reconfigure your project to have the JRE System Library point to the jdk jar. The classes inside your jdk jar will honour the Compiler option settings. So, once you update your project's JRE System Library to point to the jdk jar, debug on Java source code will start working.

这招对我很管用:

在窗口——>首选项——> Java——>编译器——>类文件生成下，所有选项都必须为True。 在build.xml <javac>任务中使debug="true"。 通过ant生成的war在tomcat中部署应用程序 在Debug模式下重新启动Tomcat