I deleted my ./bin folder in an Eclipse Indigo (super similar to Helios), and now I am wondering how to rebuild my Java project. I just cannot find a button like we can see in Netbeans.
For Eclipse you can find the rebuild option under Project > Clean and then select the project you want to clean up... that's all.
This will build your project and create a new bin folder.
In Eclipse there is an "Auto Build" option, which is checked by default. When it is checked, you don't need to build your project, this happens automatically. If this behaviour is unwanted, uncheck this option and click build project whenever you want.
To clean a project, select Clean Project. This will delete the bin folder, however if Auto build is checked, it will be immediatelly regenerated.
来源：https://stackoverflow.com/questions/6803322/how-to-achieve-that-eclipse-clean-and-build-aka-rebuild