Javabean+servlet+JSP(html)執行個體應用

標籤：

　　大家都知道Javabean+servlet+JSP是最簡單的MVC模式。的確，在一個小型的項目中，這個模式完全夠用。

它優雅並且簡潔。加上jQueryui的完美展示效果，讓這個模式看起來非常合適。當然這其中必不可少的是ajax和json格式的應用。

　　1、首先從資料庫(sqlserver)中擷取結果集並封裝到Javabean中。在此之前要定義你所需要的bean類。　　

/*     * 查詢Branch     */    public ArrayList<Branch> selBranch(Connection connection){        Branch branch=null;        ArrayList<Branch> list=new ArrayList<Branch>();        if (connection == null) {            return null;        }        String sql="select distinct mb.BRANCH_CD,mb.BRANCH_NM  from BRANCH mb";        try {            PreparedStatement ps=connection.prepareStatement(sql);            ResultSet rs=ps.executeQuery();            while(rs.next()){                branch =new Branch();                branch.setBranchCD(rs.getInt(1));                branch.setBranchName(rs.getString(2));                list.add(branch);            }            ps.close();        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        finally {            try {                connection.close();                connection = null;            } catch (SQLException e) {                e.printStackTrace();            }        }            return list;                                }

2、然後建立Servlet

    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub        doPost(request, response);    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub            response.setContentType("text/json; charset=utf-8");            SqlHandleTool sqlHandleTool=new SqlHandleTool();            SqlConnectTool connection=new SqlConnectTool();            ArrayList<Branch> list = sqlHandleTool.selBranch(connection.getSql2008Connection());            JSONArray jsonArray=JSONArray.fromObject(list);            PrintWriter out = response.getWriter();            out.println(jsonArray);    }

3、最後在js中應用ajax
function loadBranch(){    $.ajax({         url: "BranchsList.do",         dataType:"json",         //async: false,         success:function(data){             var options = [];                 for(var i=0;i<data.length;i++){                 options.push(‘<option value="‘ + data[i].branchCD + ‘">‘                            + data[i].branchName + ‘</option>‘);             }             $("#sel5").empty()              .html(options.join(""))              .attr("loaded", true);             count++;             exec();         },         error:function(){         }    });}

Javabean+servlet+JSP(html)執行個體應用