网址来源：http://blog.csdn.net/shuangzixing520/article/details/35225105
今天打开Myeclipse10的时候，发现server窗口出现一堆问题，问题如标题，然后下方出现了一堆java.lang.NullPointerException的问题。
java.lang.NullPointerException
at com.genuitec.eclipse.ast.deploy.core.Deployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ModuleDeployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.WebDeployment.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.Deployment.create(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.loadFromPreferences(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.init(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.DeploymentManager.getDefault(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ui.ServerTreeViewer$ServerTreeContentProvider.inputChanged(Unknown Source)
at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:276)
at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:1690)
at com.genuitec.eclipse.ast.deploy.core.ui.ServerTreeViewer.<init>(Unknown Source)
at com.genuitec.eclipse.ast.deploy.core.ui.ServerView.createPartControl(Unknown Source)
at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:375)
at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:229)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
这个问题的出现是在启动myeclipse之后出现的，这时还没有启动tomcat，因此可以排除tomcat中项目代码问题。应该是myeclipse在初始化工作空间workspace 的时候
出的问题。
仔细看下错误发现有一条 at com.genuitec.eclipse.ast.deploy.core.Deployment.这个错误，于是到工作空间下面的D:Workspaces.metadata.pluginsorg.eclipse.core.runtime.settings目录下面找到了名称为at com.genuitec.eclipse.ast.deploy的prefs文件，打开文件一开，哈哈，原来里面都是原来的一些项目信息，怪不得会报java.lang.NullPointerException错误呢。果断将此文件删除，重启myeclipse10问题解决