MyEclipse 解决 Errors running builder 'DeploymentBuilder' on project

MyEclipse保存.java文件并自动编译时报错：
Errors occurred during the build.
Errors running builder 'DeploymentBuilder' on project '项目名'.
java.lang.NullPointerException

产生此错误的原因：此项目不不是由MyEclipse创建；
所以你需要检查.project文件，添加 <nature>com.genuitec.eclipse.j2eedt.core.webnature</nature>
然后重新打开项目。