Java Web控制層傳送Json物件資料（二）
阿新 • • 發佈：2019-02-09
Ext資料查詢類表顯示：
案例：學生管理系統，採用Ext中AJax非同步獲取資料庫中資料並且展現在網頁前端
1、客戶端簡單實現：
createWindow : function(){ var desktop = this.app.getDesktop(); var win = desktop.getWindow('test-win'); if(!win){ var sid = ""; var nn=[]; var studentid=""; // var adminid=''; var page = 20;//每頁最多顯示20 // var ad; var ds = new Ext.data.Store({ autoLoad:true, pruneModifiedRecords : true, baseParams: {limit:page}, proxy:new Ext.data.HttpProxy({url:'./'+OS_StudentCHAXU}), reader:new Ext.data.JsonReader({root:'root',totalProperty:'totalCount'}, [{name:'studentid'},{name:'studentname'},{name:'studentbir'},{name:'studentsex'}]) // listeners:{ // 'datachanged':function(){ // Ext.getCmp("student_remove").setDisabled(true); // Ext.getCmp("student_modify").setDisabled(true); // } // } }); var sm = new Ext.grid.CheckboxSelectionModel({ handleMouseDown : Ext.emptyFn,//一個空方法 //加入一個事件監聽 listeners : { //當選中狀態發生改變時觸發 selectionchange : function(selm) {//selm為SelectionModel監聽 if (selm.hasSelection()) {//如果有選中的行，返回true if (selm.getCount() == 1) {//獲取選中行總數 nn = []; //返回被第一條被選中的記錄Record,data描述了當前Record的資料,domain為其中一個欄位key nn.push(selm.getSelected().data.studentid); Ext.getCmp("student_modify").setDisabled(false); studentid=selm.getSelected().data.studentid; } else { //返回所有選中記錄Array var record = selm.getSelections(); nn = []; for ( var i = 0; i < record.length; i++) { nn.push(record[i].data.studentid); } Ext.getCmp("student_modify").setDisabled(true); } //域移除按鈕有效與否 Ext.getCmp("student_remove").setDisabled(false); } else { Ext.getCmp("student_remove").setDisabled(true); Ext.getCmp("student_modify").setDisabled(true); } } } }); var cm = new Ext.grid.ColumnModel([ new Ext.grid.RowNumberer(),sm, {header: "學生ID", width: 70, sortable: true, dataIndex: 'studentid',hideable : false}, {header: "學生姓名", width: 70, sortable: true,dataIndex: 'studentname'}, {header: "出生年月",width:70,sortable: true,dataIndex: 'studentbir'}, {header: "性別",width:70,sortable: true,dataIndex: 'studentsex'} ]); String.prototype.endWith=function(str){ if(str==null||str==""||this.length==0||str.length>this.length) return false; if(this.substring(this.length-str.length)==str) return true; else return false; return true; } win = desktop.createWindow({ id :'test-win', title:'學生資訊', width:'50%', height:450, shim:false, animCollapse:false, constrain:true, layout: 'fit', items: new Ext.grid.GridPanel({ border:false, bbar: new Ext.PagingToolbar({ pageSize: page, store: ds, displayInfo: true, afterPageText: '/ {0}', beforePageText: '頁', firstText : "第一頁", prevText : "上一頁",// update nextText : "下一頁", lastText : "最後頁", refreshText : "重新整理", displayMsg: '顯示第 <em>{0}</em> 條到 <em>{1}</em> 條記錄，一共 <em>{2}</em> 條', emptyMsg: "沒有記錄" }), cm :cm, sm:sm, loadMask:{msg:"資料載入中...."}, store:ds, viewConfig: { forceFit:true },
以上是一個簡單顯示介面，主要資料獲取是在ds中通過
baseParams: {limit:page},
proxy:new Ext.data.HttpProxy({url:'./'+OS_StudentCHAXU}),
reader:new Ext.data.JsonReader({root:'root',totalProperty:'totalCount'}, [{name:'studentid'},{name:'studentname'},{name:'studentbir'},{name:'studentsex'}])
得到結果，然後進入OS_StudentCHAXU控制器處理查詢並返回結果：
2、控制層、DAO層實現，下面是採用Spring註釋來註冊服務
bean物件：
package com.xiaoli.form; public class Student implements java.io.Serializable{ private static final long serialVersionUID = 1L; private String studentid; private String studentname; private String studentbir; private String studentsex; // public Student(String studentid, String studentname,String studentbir, // String studentsex) { // super(); // this.studentid = studentid; // this.studentname = studentname; // this.studentbir = studentbir; // this.studentsex = studentsex; // } public String getStudentid() { return studentid; } public void setStudentid(String studentid) { this.studentid = studentid; } public String getStudentname() { return studentname; } public void setStudentname(String studentname) { this.studentname = studentname; } public String getStudentbir() { return studentbir; } public void setStudentbir(String studentbir) { this.studentbir = studentbir; } public String getStudentsex() { return studentsex; } public void setStudentsex(String studentsex) { this.studentsex = studentsex; } }
控制層類：
package com.avcon.action.os;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.avcon.dao.impl.StudentlistDaoImpl;
import com.avcon.util.ActionUrlManage;
import com.avcon.util.BeanConverter;
import com.avcon.util.ConnManager;
import com.avcon.util.Function;
import com.avcon.util.MessageResolver;
import com.avcon.util.RequestUtils;
import com.avcon.util.ResponseUtils;
import com.avcon.form.OrgList;
import com.avcon.form.Student;
import com.avcon.form.SysAdmin;
/**
* Test 學生管理
* @author fish
*
*/
@Controller
public class TestAction {
@Autowired
StudentlistDaoImpl sldi;
static Logger log=Logger.getLogger(TestAction.class);
@RequestMapping(value=ActionUrlManage.OS_StudentCHAXU,method= RequestMethod.POST)
public void QueryAll(HttpServletRequest r,HttpServletResponse rp,ModelMap model){
try {
int start = 0;
String query=r.getParameter("query");
String where="";
if(query==null)where=" 1=1 ";
else{
query=query.trim();
where =" s.studentid like '%"+query+"%' or s.student like '%"+Function.PageToDb(query)+"'%";
}
if(r.getParameter("start") == null){
model.addAttribute("start", 0);
}else{
start = Integer.parseInt(r.getParameter("start"));
}
int limit = Integer.parseInt(r.getParameter("limit"));
List<Student> list=sldi.getAll(start,limit,where);
int num = Function.cwhere("studentid","sys_student_test o",where);
JSONObject json = new JSONObject();
JSONArray arr = new JSONArray();
System.out.println("-------------"+num);
for (Student s : list) {
arr.put(new JSONObject(s));
}
json.put("root", arr);
json.append("totalCount", num);
ResponseUtils.renderJson(rp,json.toString());
} catch (JSONException e) {
log.error(e.getMessage(),e);
}catch (Exception e){
log.error(e.getMessage(),e);
}
}}
以上的StudentlistDaoImpl是服務層處理類，也就是資料訪問層，得到的資料物件陣列都轉換為一個JSONObject，再將其置於JSONArray中，最後返回給客服端的資料依然還是將上面的資料打包為JSONObject並轉換為String返回。
下面是顯示效果：
