Eclipse "Unable to install breakpoint due to missing line number attributes..."

 Eclipse下Debug时弹出错误“Unable to install breakpoint due to missing line number attributes,Modify compiler options to generate line number attributes"

遇到这个错误时找到的解答方案汇总：
1、使用Ant编译时，未打开debug开关，在写javac 任务时确认debug=true，否则不能调试。THe settings for the eclipse compiler don't affect the ant build and even if you launch the ant build from within eclipse. ant controls it's own compiler settings.you can tell ant to generate debugging info like this 'javac ... debug="true".../>（我的问题是因为这个原因）；
2、编译器的设置问题，window->preferences->java->Compiler在compiler起始页，classfile Generation区域中确认已经勾选了All line number attributes to generated class files。如果已经勾选，从新来一下再Apply一下。或者从项目层次进行设定，项目属性->java compiler同样在起始页，确定已经勾选
Eclipse报的这个错，无非就这两个原因造成的