首先下载tomcat插件： http://www.eclipsetotale.com/tomcatPlugin.html，下载最新的3.3版本；
由于我的eclipse是通过yum自动安装的，因此eclipse在默认的路径下/usr/lib/eclipse/，将tomcat插件解压后，把com.sysdeo.eclipse.tomcat_3.3.0文件夹放在eclipse默认路径下的/plugins路径下；
然后重启eclipse，即可看到有tomcat图标了。
配置tomcat的文章，参考：http://blog.csdn.net/njchenyi/article/details/6042760，虽然是windows的，但没有本质差别；
创建servlet，参考：http://blog.csdn.net/njchenyi/article/details/6042763；
使用命令行，也可以编译servlet.
首先，将编译用的api文件拷贝到java文件同一目录下，我用的是/usr/share/java/servlet_2_4_api.jar；
然后使用javac -classpath servlet_2_4_api.jar HelloWorldExample11.java进行编译；即可生成class文件；
HelloWorldExample11.java代码如下：
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* The simplest possible servlet.
*
* @author James Duncan Davidson
*/
public class HelloWorldExample11 extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
ResourceBundle rb =
ResourceBundle.getBundle("LocalStrings",request.getLocale());
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
String title = rb.getString("helloworld.title");
out.println("<title>" + title + "</title>");
out.println("</head>");
out.println("<body bgcolor="white">");
// note that all links are created to be relative. this
// ensures that we can move the web application that this
// servlet belongs to to a different place in the url
// tree and not have any harmful side effects.
// XXX
// making these absolute till we work out the
// addition of a PathInfo issue
out.println("<a href="../helloworld.html">");
out.println("<img src="../images/code.gif" height=24 " +
"width=24 align=right border=0 alt="view code"></a>");
out.println("<a href="../index.html">");
out.println("<img src="../images/return.gif" height=24 " +
"width=24 align=right border=0 alt="return"></a>");
out.println("<h1>" + title + "</h1>");
out.println("</body>");
out.println("</html>");
}
}