分層構建項目

分層構建WEB項目

如何分層

···sequence

每一層只依賴於下一層，不能跨層依賴

每層作用

• WEB客戶端

  該層只負責提交表單到後臺的Servlet，通過request取得數據等，打印輸出到表格顯示

• Servlet層
  關鍵的一層，接收到表單數據，調用業務邏輯，處理業務。
  相同的servlet可以先抽象出來一個 抽象類 繼承使用，比如對於物料的 增，刪，改，查 ，都需要使用業務邏輯 Manager 類，可以 在 init()時即取得該 類的對象，其他類直接繼承
  即該層可以需要創建業務邏輯層對象

抽象類

package com.houlu.drp.basedata.web;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;

import com.houlu.drp.basedata.dao.ItemDao;
import com.houlu.drp.basedata.manager.ItemManager;
import com.houlu.drp.basedata.manager.ItemManagerImpl;
import com.houlu.drp.util.BeanFactory;


/**
 * 物料servlet抽象
 * @author Administrator
 *
 */
public abstract class AbstractItemServlet extends HttpServlet {

    protected ItemManager itemManager;

    public AbstractItemServlet(){

        System.out.println("AbstractItemServlet-----------Construct");
    }

    @Override
    public void init() throws ServletException{

    //  itemManager = (ItemManager)BeanFactory.getInstance().getServiveObject("itemManager");

        BeanFactory beanFactory = (BeanFactory)this.getServletContext().getAttribute("beanFactory");
        itemManager = (ItemManager)beanFactory.getServiveObject(ItemManager.class);
    }
}

繼承類

package com.houlu.drp.basedata.web;

import java.io.IOException;

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

import com.houlu.drp.basedata.domain.Item;
import com.houlu.drp.basedata.manager.ItemManager;
import com.houlu.drp.basedata.manager.ItemManagerImpl;
import com.houlu.drp.datadict.domain.ItemCategory;
import com.houlu.drp.datadict.domain.ItemUnit;

public class AddItemServlet extends AbstractItemServlet {

    private ItemManager itemManager;

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        //取得表單數據
        String itemNo = request.getParameter("itemNo");
        String itemName = request.getParameter("itemName");
        String spec = request.getParameter("spec");
        String pattern = request.getParameter("pattern");
        String category = request.getParameter("category");
        String unit = request.getParameter("unit");

        //構造item對象
        Item item = new Item();
        item.setItemNo(itemNo);
        item.setItemName(itemName);
        item.setSpec(spec);
        item.setPattern(pattern);


        //構造物料類別
        ItemCategory itemCategory = new ItemCategory();
        itemCategory.setId(category);
        item.setItemCategory(itemCategory);

        //構造物料單位
        ItemUnit itemUnit = new ItemUnit();
        itemUnit.setId(unit);
        item.setItemUnit(itemUnit);

    //  itemManager = new ItemManagerImpl();

        try {
            itemManager.addItem(item);
        } catch (Exception e) {
            request.setAttribute("add_message", "添加物料失敗，失敗代碼 ["+itemNo+"]");
        }
        //重定向
        //response.sendRedirect(requset.getContextPath()+"/basedata/item_maint.jsp");
        request.setAttribute("add_message", "添加成功");
        //轉發
        request.getRequestDispatcher("/basedata/item_maint.jsp").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

• 業務邏輯
  該層只與業務邏輯打交道，該層創建DAO層的connection
  業務邏輯層創建固定接口，然後不同類實現。

業務邏輯接口

package com.houlu.drp.basedata.manager;

import java.sql.Connection;

import com.houlu.drp.basedata.domain.Item;
import com.houlu.drp.util.PageModel;

/**
 * 物料業務邏輯層接口
 * @author Administrator
 *
 */
public interface ItemManager {

    /**
     * 添加物料
     * @param conn
     * @param item
     */
    public void addItem(Item item);

    /**
     * 根據物料代碼集合刪除
     * @param conn
     * @param itemNos
     */
    public void delItem(String[] itemNos);

    /**
     * 修改物料
     * @param conn
     * @param item
     */
    public void modifyItem(Item item);

    /**
     * 根據物料代碼查詢
     * @param conn
     * @param itemNo
     * @return
     */
    public Item findItemById(String itemNo);

    /**
     * 根據條件分頁查詢
     * @param pageNo
     * @param pageSize
     * @param condation
     * @return
     */
    public PageModel findItemList(int pageNo, int pageSize, String condation);
}

實現類

package com.houlu.drp.basedata.manager;

import java.sql.Connection;

import com.houlu.drp.basedata.dao.ItemDao;
import com.houlu.drp.basedata.dao.ItemDaoFactory;
import com.houlu.drp.basedata.dao.ItemDaoFactory4SqlServer;
import com.houlu.drp.basedata.domain.Item;
import com.houlu.drp.util.ApplicationException;
import com.houlu.drp.util.BeanFactory;
import com.houlu.drp.util.DbUtil;
import com.houlu.drp.util.PageModel;
import com.houlu.drp.util.XmlConfigReader;

/**
 * 物料管理接口實現
 * @author Administrator
 *
 */
public class ItemManagerImpl implements ItemManager {

    private ItemDao itemDao = null;

    public ItemManagerImpl(){
        //System.out.println("new------------------------ItemManagerImplClass");
        itemDao = (ItemDao)BeanFactory.getInstance().getDaoObject(ItemDao.class);
    }

    public void addItem(Item item) {
        Connection conn = null;

        try {
            conn = DbUtil.getConnection();
                if(itemDao.findItemById(conn, item.getItemNo())!=null){
                    throw new ApplicationException("該代碼物料已經存在");
                }
            itemDao.addItem(conn, item);
        } finally{
            DbUtil.close(conn);
        }

    }

    @Override
    public void delItem(String[] itemNos) {
        // TODO Auto-generated method stub

    }

    @Override
    public void modifyItem(Item item) {
        // TODO Auto-generated method stub

    }

    @Override
    public Item findItemById(String itemNo) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public PageModel findItemList(int pageNo, int pageSize, String condation) {
        Connection conn = null;
        PageModel pageModel = null;
        try {
            conn = DbUtil.getConnection();
            pageModel = itemDao.findItemList(conn, pageNo, pageSize, condation);
        } finally{
            DbUtil.close(conn);
        }

        return pageModel;
    }


}

• 持久化層
  該層與數據庫打交道，取得業務邏輯層的connection進行sql操作

上層接口

package com.houlu.drp.basedata.dao;

import java.sql.Connection;

import com.houlu.drp.basedata.domain.Item;
import com.houlu.drp.util.PageModel;

/**
 * 物料數據訪問接口
 * @author Administrator
 *
 */
public interface ItemDao {

    /**
     * 添加物料
     * @param conn
     * @param item
     */
    public void addItem(Connection conn,Item item);

    /**
     * 根據物料代碼集合刪除
     * @param conn
     * @param itemNos
     */
    public void delItem(Connection conn,String[] itemNos);

    /**
     * 修改物料
     * @param conn
     * @param item
     */
    public void modifyItem(Connection conn,Item item);

    /**
     * 根據物料代碼查詢
     * @param conn
     * @param itemNo
     * @return
     */
    public Item findItemById(Connection conn,String itemNo);

    /**
     * 根據條件分頁查詢
     * @param pageNo
     * @param pageSize
     * @param condation
     * @return
     */
    public PageModel findItemList(Connection conn,int pageNo, int pageSize, String condation);

}

具體實現

package com.houlu.drp.basedata.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.houlu.drp.basedata.domain.Item;
import com.houlu.drp.datadict.domain.ItemCategory;
import com.houlu.drp.datadict.domain.ItemUnit;
import com.houlu.drp.util.ApplicationException;
import com.houlu.drp.util.DbUtil;
import com.houlu.drp.util.PageModel;

public class ItemDao4SqlServerImpl implements ItemDao {

    @Override
    public void addItem(Connection conn, Item item) {
        StringBuffer sb = new StringBuffer();
        sb.append("INSERT INTO T_ITEMS ");
        sb.append("(ITEM_NO, ITEM_CATEGORY_ID, ITEM_UNIT_ID, ITEM_NAME, SPEC, PATTERN) ");
        sb.append("VALUES (?,?,?,?,?,?)");
        String sql = sb.toString();

        PreparedStatement pstmt = null;
        try {
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, item.getItemNo());
            pstmt.setString(2, item.getItemCategory().getId());
            pstmt.setString(3, item.getItemUnit().getId());
            pstmt.setString(4, item.getItemName());
            pstmt.setString(5, item.getSpec());
            pstmt.setString(6, item.getPattern());
            pstmt.executeUpdate();

        } catch (Exception e) {
            e.printStackTrace();
            throw new ApplicationException("添加物料失敗");
        } finally{
            DbUtil.close(pstmt);
        }

    }

    @Override
    public void delItem(Connection conn, String[] itemNos) {
        // TODO Auto-generated method stub

    }

    @Override
    public void modifyItem(Connection conn, Item item) {
        // TODO Auto-generated method stub

    }

    @Override
    public Item findItemById(Connection conn, String itemNo) {
        StringBuffer sb = new StringBuffer();
        sb.append("select i.ITEM_NO,i.ITEM_NAME,I.SPEC,I.PATTERN,i.ITEM_CATEGORY_ID as category_id, d1.NAME as category_name,i.ITEM_UNIT_ID as unit_id, d2.NAME as unit_name ");
        sb.append("from T_ITEMS i,T_DATA_DIC d1, T_DATA_DIC d2 ");
        sb.append("where i.ITEM_CATEGORY_ID = d1.ID and i.ITEM_UNIT_ID = d2.ID and i.ITEM_NO = ?");
        String sql = sb.toString();

        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Item item = null;
        try {
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, itemNo);
            rs = pstmt.executeQuery();
            if(rs.next()){
                item = new Item();
                item.setItemNo(rs.getString("item_no"));
                item.setItemName(rs.getString("item_name"));
                item.setSpec(rs.getString("spec"));
                item.setPattern(rs.getString("pattern"));

                //構造ItemCategory
                ItemCategory ic = new ItemCategory();
                ic.setId(rs.getString("category_id"));
                ic.setName(rs.getString("category_name"));
                item.setItemCategory(ic);

                //構造ItemUnit
                ItemUnit iu = new ItemUnit();
                iu.setId(rs.getString("unit_id"));
                iu.setName(rs.getString("unit_name"));
                item.setItemUnit(iu);
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new ApplicationException("根據物料代碼查詢出錯");
        }finally{
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }

        return item;
    }

    @Override
    public PageModel findItemList(Connection conn,int pageNo, int pageSize, String condation) {
        StringBuffer sb = new StringBuffer();
        sb.append("select * from( ");
        sb.append("select ROW_NUMBER() over(order by i.ITEM_NO) as r2,* from( ");
        sb.append("select ");
        sb.append("ROW_NUMBER() over(order by a.ITEM_NO) as r1,a.ITEM_NO,a.item_name,a.SPEC,a.PATTERN,a.ITEM_CATEGORY_ID,b.NAME as item_category_name,a.ITEM_UNIT_ID,c.NAME as item_unit_name ");
        sb.append("from T_ITEMS a,T_DATA_DIC b,T_DATA_DIC c where a.ITEM_CATEGORY_ID=b.ID and a.ITEM_UNIT_ID = c.ID ");
        if(condation!=null&&!"".equals(condation)){
            sb.append("and a.ITEM_NAME like '"+ condation +"%' ");
        }
        sb.append(") i where i.r1<= ? ");
        sb.append(")o where o.r2 > ? ");

        String sql = sb.toString();

    //  System.out.println(sql);
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        PageModel pageModel = null;
        try {
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, pageNo*pageSize);
            pstmt.setInt(2, (pageNo-1)*pageSize);
            rs = pstmt.executeQuery();
            List<Item> itemList = new ArrayList<Item>();
            while(rs.next()){
                Item item = new Item();
                item = new Item();
                item.setItemNo(rs.getString("item_no"));
                item.setItemName(rs.getString("item_name"));
                item.setSpec(rs.getString("spec"));
                item.setPattern(rs.getString("pattern"));

                //構造ItemCategory
                ItemCategory ic = new ItemCategory();
                ic.setId(rs.getString("item_category_id"));
                ic.setName(rs.getString("item_category_name"));
                item.setItemCategory(ic);

                //構造ItemUnit
                ItemUnit iu = new ItemUnit();
                iu.setId(rs.getString("item_unit_id"));
                iu.setName(rs.getString("item_unit_name"));
                item.setItemUnit(iu);

                itemList.add(item);
            }
            pageModel = new PageModel();
            pageModel.setPageNo(pageNo);
            pageModel.setPageSize(pageSize);
            pageModel.setList(itemList);

            //根據條件取得記錄數
            int totalRecorders = getTotalRecords(conn, condation);
            pageModel.setTotalRecords(totalRecorders);

        } catch (Exception e) {
            e.printStackTrace();
            throw new ApplicationException("分頁查詢失敗");
        }finally{
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }

        return pageModel;
    }

    /**
     * 根據條件取得記錄數
     * @param conn
     * @param condation
     * @return
     * @throws SQLException
     */
    private int getTotalRecords(Connection conn,String condation)throws SQLException{
        String sql = "select count(*) from t_items ";
            if(condation!=null&&!"".equals(condation)){
                sql += "where ITEM_NAME like '"+ condation +"%' ";      
            }
        //System.out.println(sql);
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        int temp=0;
        try {
            pstmt = conn.prepareStatement(sql);
            rs = pstmt.executeQuery();
            rs.next();
            temp = rs.getInt(1);
        }finally{
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }
        return temp;
    }


    public static void main(String[] args){
        Connection conn = DbUtil.getConnection();
        ItemDao itemDao = new ItemDao4SqlServerImpl();
        itemDao.findItemList(conn, 1, 5, "當");
    }

}