在使用Spring Tool Suite (STS)启动Java EE项目时，我们也会遇到这个消息，但是我们可以忽略这个消息，因为一切都很好。

对于使用Tomcat服务器的Web项目，我通过以下步骤解决了这个问题。

打开窗口->显示视图->其他->服务器。 双击运行中的tomcat服务器。(打开tomcat服务器概述) 现在点击启动配置链接。 单击sources选项卡。 单击Add。 选择java项目 将显示您的所有项目。 选择打开“您要调试。” 保存配置并重新启动或构建应用程序。

因为我安装了6个不同版本的Java，所以我必须更改默认的JDK遵从性，以匹配我想使用的Java版本。当所有内容都使用Java 1.6构建/编译时，Eclipse默认将编译器遵从级别设置为Java 1.7。

所以我所做的就是

在eclipse菜单中，进入“窗口->首选项->Java->编译器” 在JDK遵从性下，我将编译器遵从性级别从1.7更改为1.6

现在Eclipse不再抱怨“无法插入缺少行号信息的断点”，并且调试断点实际上工作了!!

如果其他方法都不起作用，打开调试透视图，清除所有现有的断点，然后重新设置它们。

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".

在使用Spring Tool Suite (STS)启动Java EE项目时，我们也会遇到这个消息，但是我们可以忽略这个消息，因为一切都很好。