Spring MVC模式示例（采用解耦控制器）

Product

package com.mstf.bean;

import java.io.Serializable;
/**
 * Product类，封装了一些信息，包含三个属性
 * @author wangzheng
 *
 */
public class Product implements Serializable {

	private static final long serialVersionUID = 1L;

	private String name;
	private String description;
	private float price;

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	public float getPrice() {
		return price;
	}
	public void setPrice(float price) {
		this.price = price;
	}

}

　　ProductForm

package com.mstf.bean.form;
/**
 * ProductForm是表单类
 * 作用：当数据校验失败时，用于保存和展示用户在原始表单的输入
 * @author wangzheng
 *
 */
public class ProductForm {
	private String name;
	private String description;
	private String price;

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	public String getPrice() {
		return price;
	}
	public void setPrice(String price) {
		this.price = price;
	}

}

　　Controller

package com.mstf.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public interface Controller {

	String handleRequest(HttpServletRequest req,HttpServletResponse resp);
}

　　InputProductController

package com.mstf.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class InputProductController implements Controller {

	@Override
	public String handleRequest(HttpServletRequest req,HttpServletResponse resp) {
		return "/WEB-INF/jsp/ProductForm.jsp";
	}
}

　　SaveProductController

package com.mstf.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mstf.bean.Product;
import com.mstf.bean.form.ProductForm;

public class SaveProductController implements Controller {

	@Override
	public String handleRequest(HttpServletRequest req,HttpServletResponse resp) {
		// 构建一个ProductForm表单对象
        ProductForm productForm = new ProductForm();
        // 写入表单对象
        productForm.setName(req.getParameter("name"));
        productForm.setDescription(req.getParameter("description"));
        productForm.setPrice(req.getParameter("price"));

        // 创建模型
        Product product = new Product();
        product.setName(productForm.getName());
        product.setDescription(productForm.getDescription());
        try {
        	product.setPrice(Float.parseFloat(productForm.getPrice()));
        } catch (NumberFormatException e) {
        	e.printStackTrace();
        }
        // 添加
        req.setAttribute("product", product);
        return "/WEB-INF/jsp/ProductDetails.jsp";
	}
}

　　DispatcherServlet

package com.mstf.servlet;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mstf.controller.InputProductController;
import com.mstf.controller.SaveProductController;

public class DispatcherServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	@Override
	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		process(req, resp);
	}

	@Override
	public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		process(req, resp);
	}
	/**
	 * 这个方法用来处理所有输入请求
	 * @param req
	 * @param resp
	 * @throws IOException
	 * @throws ServletException
	 */
	private void process(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException {
		req.setCharacterEncoding("UTF-8"); //转码
		resp.setCharacterEncoding("UTF-8");
		String uri=req.getRequestURI(); // 获取请求URI
		int lastIndex=uri.lastIndexOf("/");
		String action=uri.substring(lastIndex+1); // 获取action名称
		String dispatchUrl=null;
		// 执行方法
		if(action.equals("product_input.action")) {
			InputProductController controller=new InputProductController();
			dispatchUrl=controller.handleRequest(req, resp);
		} else if (action.equals("product_save.action")) {
			SaveProductController controller=new SaveProductController();
			dispatchUrl=controller.handleRequest(req, resp);
		}
		if(dispatchUrl!=null) {
			RequestDispatcher rd=req.getRequestDispatcher(dispatchUrl);
			rd.forward(req, resp);
		}
	}
}