EASYUI之DataGrid的使用（java）

首先建立了一个html文件，这里对EASYUI使用的是JS加载方式，这里我把JS的代码放到单独的一个文件夹中，也可以把JS的代码和html放在一起。下面是JS文件中的代码。

这里我用Servlet来处理数据，也可以用struts2更为方便。

$(function(){

$("#box").datagrid({

title : "用户列表",

width : 850,

striped: true,

//height: 200,

autoRowHeight : true,

rownumbers : true,

collapsible : true,

pageNumber : 1,

pagination : true,

pageSize : 5,

pageList : [ 5, 10, 15, 20 ],

loadMsg: "信息加载中",

url : "servlet/SearchServlet",

fitColumns : false,

columns : [[

{field : 'EMPNO',title : '员工号', width: 100, align: 'center'},

{field : 'ENAME',title : '姓名', width: 100, align: 'center'},

{field : 'JOB',title : '职务', width: 100, align: 'center'},

{field : 'MGR',title : '经理', width: 100, align: 'center'},

{field : 'HIREDATE',title : '日期', width: 120, align: 'center'},

{field : 'SAL',title : '薪水', width: 100, align: 'center'},

{field : 'COMM',title : '日用', width: 100, align: 'center'},

{field : 'DEPTNO',title : '公寓号', width: 100, align: 'center'}

]],

});

});

下面是连接数据库的代码，后面会反复用到。

package com.DB;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

public class DB {

public static Connection getConnection(){

Connection conn = null;

try {

Class.forName("oracle.jdbc.driver.OracleDriver");

conn = DriverManager.getConnection("jdbc:oracle:thin:@202.113.76.131:1521:orcl", "scott", "zhengD3064301");

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return conn;

}

public static void close(PreparedStatement pstmt){

if(pstmt != null){

try {

pstmt.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

public static void close(Connection conn) {

if (conn != null) {

try {

conn.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

public static void close(ResultSet rs) {

if (rs != null) {

try {

rs.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

由于DataGrid是用JSON来传递数据的，就需要设置特殊的类来完成JSON的转换。一个是DBRecord ，一个是DBTable 如下：

package com.DB;

import java.io.Serializable;

import java.util.HashMap;

public class DBRecord extends HashMap<String, String> implements Serializable {

private static final long serialVersionUID = 1L;

public DBRecord(){

super();

}

}

package com.DB;

import java.io.Serializable;

import java.util.ArrayList;

public class DBTable extends ArrayList<DBRecord> implements Serializable {

private static final long serialVersionUID = 1L;

public DBTable(){

super();

}

}

现在就把前期的准备工作做完了，开始写Servlet来处理数据rows和page是固定的参数，这里会用到方法getAllData(strRows, strPage);getDataSetInfoByCon(strSql, rowCount, page);getRowCount(String strSql);

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

String result = "";

String strRows = request.getParameter("rows");

String strPage = request.getParameter("page");

if(strRows == null){

strRows = "0";

}

if(strPage == null){

strPage = "0";

}

result = BaseDao.getInstance().getAllData(strRows, strPage);

response.setCharacterEncoding("UTF-8");

PrintWriter out = response.getWriter();

out.write(result);

out.flush();

out.close();

}

public String getAllData(String strRows,String strPage){

int rowCount = 0;

int page = 0;

String result;

DBTable data = new DBTable();

Map<String, Object> mapresult = new HashMap<String, Object>();

String strSql = "select * from EMP order by empno";

if(strRows != ""){

rowCount = Integer.parseInt(strRows);

}

if(strPage != ""){

page = Integer.parseInt(strPage);

}

data = getDataSetInfoByCon(strSql, rowCount, page);

rowCount = getRowCount("select * from EMP");

mapresult.put("total", rowCount);

mapresult.put("rows",data);

JSONObject jo = JSONObject.fromObject(mapresult);

result = jo.toString();

return result;

}

public DBTable getDataSetInfoByCon(String strSql , int rowCount , int page){

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

ResultSetMetaData rsmd = null;

DBTable dbt = new DBTable();

int columnCount = 0;

try {

conn = DB.getConnection();

pstmt = conn.prepareStatement(strSql,ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);

rs = pstmt.executeQuery();

rsmd = rs.getMetaData();

columnCount = rsmd.getColumnCount();

if(rowCount > 0){

pstmt.setMaxRows(page * rowCount);

}

if(rowCount > 0 && page > 1){

rs.absolute((page - 1) * rowCount);

}

while(rs.next()){

DBRecord dbr = new DBRecord();

for(int i = 1; i <= columnCount; i++){

dbr.put(rsmd.getColumnName(i), rs.getString(i));

}

dbt.add(dbr);

}

DB.close(rs);

DB.close(pstmt);

DB.close(conn);

} catch (SQLException e) {

e.printStackTrace();

}

return dbt;

}

public int getRowCount(String strSql){

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

int count = 0;

try {

conn = DB.getConnection();

pstmt = conn.prepareStatement(strSql);

rs = pstmt.executeQuery();

/*rs.last();

count = rs.getRow();*/

while(rs.next()){

count ++;

}

DB.close(rs);

DB.close(pstmt);

DB.close(conn);

} catch (SQLException e) {

e.printStackTrace();

}

return count;

}