我已经下载了Eclipse并试图创建一个示例servlet程序，但是我遇到了以下错误

Question

Multiple markers at this line
    - The type java.io.ObjectInputStream cannot be resolved. It is 
     indirectly referenced from required .class files
    - The type java.io.ObjectInputStream cannot be resolved. It is 
     indirectly referenced from required .class files

我已正确配置构建路径。我正在使用Java 8更新111和Apache Tomcat 7，两者的库都被正确引用。

Answer 1

按CTRL + SHIFT + o并查看它是否具有魔力？