有一段程序如下:
package ch3;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Vector;
import javax.servlet.jsp;public class ItemManager{
private Vector m_vector=new Vector();
protected ServletContext m_application;
private boolean m_denyPhysicalPath;

public ItemManager(){
}

public final void initialize(PageContext pageContext) throws ServletException{
m_application=pageContext.getServletContext();
}
.......
}编译时出现如下错误:
C:\>javac ch3\ItemManager.java
ch3\ItemManager.java:8: 软件包 javax.servlet 不存在
import javax.servlet.jsp;
                     ^
ch3\ItemManager.java:12: 找不到符号
符号: 类 ServletContext
位置: 类 ch3.ItemManager
                protected ServletContext m_application;
                          ^
ch3\ItemManager.java:18: 找不到符号
符号: 类 PageContext
位置: 类 ch3.ItemManager
                public final void initialize(PageContext pageContext) throws Ser
vletException{
                                             ^
请各位高手指点以下!谢谢了!