基于Struts2的jTable使用
由于有个项目中需要用到数据显示的表格插件，经过查阅资料发现了这款插件，在使用过程中也遇到好的问题，不过都解决了，所有在闲暇时间把这款插件结合struts2 做一个demo给大家，希望对看到的人有所帮助。
文章中有什么错误请指出，遇到问题也可以留言。
转发时候请说明一下，尊重我的劳动成果。谢谢！
一、jTable介绍
官方网站：http://www.jtable.org/
jTable是基于AJAX不要编码HTML或者Javascript CRUD 表的的jQuery插件。
Java Servlet demo : http://www.programming-free.com/search/label/jTable
二、环境搭建
1.新建工程
2.配置struts2环境
将struts2的lib包放入工程中，配置 web.xml 文件, 写struts.xml文件 。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="true" />
<constant name="struts.custom.i18n.resources" value="message" />
<constant name="struts.i18n.encoding" value="utf-8" />
<!--一定要继承 json-default-->
<package name="student" extends="json-default" namespace="/student">
<action name="listStudentByPageAction" class="com.action.StudentAction"
method="listStudentByPage">
<result type="json"></result>
</action>
<action name="getJSONResult" class="com.action.StudentAction"
method="listStudentByPage">
<result type="json" />
</action>
</package>
</struts>3.将jtable的相关文件放入工程中（文件可从官方网站下载）
三、编写程序
项目源码结构如下图所示
1.student
package com.bean;
public class Student {
private int studentId;
private String name;
private String department;
private String emailId;
public int getStudentId() {
return studentId;
}
public String getName() {
return name;
}
public String getDepartment() {
return department;
}
public String getEmailId() {
return emailId;
}
public void setStudentId(int studentId) {
this.studentId = studentId;
}
public void setName(String name) {
this.name = name;
}
public void setDepartment(String department) {
this.department = department;
}
public void setEmailId(String emailId) {
this.emailId = emailId;
}
}2.StudentDao
package com.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import com.bean.Student;
import com.jdbc.DataAccessObject;
public class StudentDao {
private Connection dbConnection;
private PreparedStatement pStmt;
public StudentDao() {
dbConnection = DataAccessObject.getConnection();
}
public void addStudent(Student student) {
String insertQuery = "INSERT INTO STUDENT(STUDENTID, NAME, "
+ "DEPARTMENT, EMAIL) VALUES (?,?,?,?)";
try {
pStmt = dbConnection.prepareStatement(insertQuery);
pStmt.setInt(1, student.getStudentId());
pStmt.setString(2, student.getName());
pStmt.setString(3, student.getDepartment());
pStmt.setString(4, student.getEmailId());
pStmt.executeUpdate();
} catch (SQLException e) {
System.err.println(e.getMessage());
}
}
public void deleteStudent(int userId) {
String deleteQuery = "DELETE FROM STUDENT WHERE STUDENTID = ?";
try {
pStmt = dbConnection.prepareStatement(deleteQuery);
pStmt.setInt(1, userId);
pStmt.executeUpdate();
} catch (SQLException e) {
System.err.println(e.getMessage());
}
}
public void updateStudent(Student student) {
String updateQuery = "UPDATE STUDENT SET NAME = ?, "
+ "DEPARTMENT = ?, EMAIL = ? WHERE STUDENTID = ?";
try {
pStmt = dbConnection.prepareStatement(updateQuery);
pStmt.setString(1, student.getName());
pStmt.setString(2, student.getDepartment());
pStmt.setString(3, student.getEmailId());
pStmt.setInt(4, student.getStudentId());
pStmt.executeUpdate();
} catch (SQLException e) {
System.err.println(e.getMessage());
}
}
public int getCount() {
String count = "SELECT COUNT(*) FROM STUDENT";
int i = 0;
try {
Statement st = dbConnection.createStatement();
ResultSet rs = st.executeQuery(count);
if (rs.next()) {
i = rs.getInt(1);
}
} catch (SQLException e) {
e.printStackTrace();
}
return i;
}
public List<Student> getAllStudentsByPage(int startRow, int pageSize) {
List<Student> students = new ArrayList<Student>();
String query = "SELECT * FROM STUDENT LIMIT ? OFFSET ?";
try {
pStmt = dbConnection.prepareStatement(query);
pStmt.setInt(1, pageSize);
pStmt.setInt(2, startRow);
ResultSet rs = pStmt.executeQuery();
// Statement stmt = dbConnection.createStatement();
// ResultSet rs = stmt.executeQuery(query);
while (rs.next()) {
Student student = new Student();
student.setStudentId(rs.getInt("STUDENTID"));
student.setName(rs.getString("NAME"));
student.setDepartment(rs.getString("DEPARTMENT"));
student.setEmailId(rs.getString("EMAIL"));
students.add(student);
}
} catch (SQLException e) {
System.err.println(e.getMessage());
}
return students;
}
}3.DataAccessObject
package com.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
public class DataAccessObject {
private static Connection connection = null;
public static Connection getConnection() {
if (connection != null)
return connection;
else {
// Store the database URL in a string
String serverName = "localhost";
String portNumber = "3306";
String sid = "test";
String dbUrl = "jdbc:mysql://" + serverName + ":" + portNumber
+ "/" + sid;
try {
Class.forName("com.mysql.jdbc.Driver");
// set the url, username and password for the database
connection = DriverManager.getConnection(dbUrl, "root", "root");
} catch (Exception e) {
e.printStackTrace();
}
return connection;
}
}
}4.StudentAcion
我只写了一个加载列表的action 各位可以按照我的方法依次编写其他函数
package com.action;
import java.util.ArrayList;
import java.util.List;
import com.bean.Student;
import com.dao.StudentDao;
import com.opensymphony.xwork2.Action;
public class StudentAction {
// 属性
private int studentId;
private String name;
private String department;
private String emailId;
private Student record;
private List<Student> records;
private String result;
private String message;
/** 分页 **/
private int jtStartIndex;
private int jtPageSize;
private int totalRecordCount;
private StudentDao dao;
public StudentAction() {
dao = new StudentDao();
}
/**
* 获取列表
*
* @return
*/
public String listStudentByPage() {
records = new ArrayList<Student>();
try {
records = dao.getAllStudentsByPage(jtStartIndex, jtPageSize);
totalRecordCount = dao.getCount();
System.out.println(records.size()+"--"+totalRecordCount);
result = "OK";
} catch (Exception e) {
e.printStackTrace();
message = e.getMessage();
result = "ERROR";
}
return Action.SUCCESS;
}
//省略 set get
}5.index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path;
%>
<title>Insert title here</title>
<link type="text/css" rel="stylesheet" href="<%=basePath%>/res/plugins/jtable/themes/metro/blue/jtable.css" />
<link type="text/css" rel="stylesheet" href="<%=basePath%>/res/css/jquery-ui-1.10.3.custom.css" />
<script type="text/javascript" src="<%=basePath%>/res/plugins/jquery-1.9.0.min.js"></script>
<script type="text/javascript" src="<%=basePath%>/res/plugins/jquery-ui-1.10.0.min.js"></script>
<script type="text/javascript" src="<%=basePath%>/res/plugins/jtable/jquery.jtable.js"></script>
</head>
<body>
<div style="width: 80%; margin-right: 10%; margin-left: 10%; text-align: center;">
<h4>AJAX based CRUD operations using jTable in J2EE</h4>
<div id="StudentTableContainer"></div>
</div>
</body>
<script type="text/javascript">
$(document).ready(function() {
$('#StudentTableContainer').jtable({
title : 'Students List',
paging: true, //Enable paging
pageSize: 10, //Set page size (default: 10)
actions : {
listAction : '<%=basePath%>/student/listStudentByPageAction',
createAction: '<%=basePath%>/student/insertStudentAction',
deleteAction: ''
},
fields : {
studentId : {
title : 'Student Id',
width : '30%',
key : true,
list : true,
edit : false,
create : true
},
name : {
title : 'Name',
width : '30%',
edit : true
},
department : {
title : 'Department',
width : '30%',
edit : true
},
emailId : {
title : 'Email',
width : '20%',
edit : true
}
}
});
$('#StudentTableContainer').jtable('load');
});
</script>
</html>四、程序调试（重要部分）
前面都是一些准备工作，即使各位按照我的步骤也一定不会运行成功，我在写这个demo的时候已经测试过了。大家也许对其中一些变量名称有疑问，请认真看下面的部分。
在StudentAction中有这七个变量
private Student record;//单条记录，这个变量在添加信息时候使用，
private List<Student> records;//数据列表，
private String result;//结果标识
private String message;//信息标识（在程序出行错误时候，jtable会 alert出这个信息，所有一般携带异常信息）
/** 分页 **/
private int jtStartIndex;//分页的开始位
private int jtPageSize;//页面大小
private int totalRecordCount;//数据列表中的记录数 上面的注释中解释了一部分，这些都是jtable要使用分页功能时候必须的变量。
下面解释为什么调试不出来的原因：
请大家看看jtable.js源码，我这里为大家复制一段
/* LOADING RECORDS *****************************************************/
/* Performs an AJAX call to reload data of the table.
*************************************************************************/
_reloadTable: function (completeCallback) {
var self = this;
//Disable table since it's busy
self._showBusy(self.options.messages.loadingMessage, self.options.loadingAnimationDelay);
//Generate URL (with query string parameters) to load records
var loadUrl = self._createRecordLoadUrl();
//Load data from server
self._onLoadingRecords();
self._ajax({
url: loadUrl,
data: self._lastPostData,
success: function (data) {
self._hideBusy();
//Show the error message if server returns error
if (data.Result != 'OK') {
self._showError(data.Message);
return;
}
//Re-generate table rows
self._removeAllRows('reloading');
self._addRecordsToTable(data.Records);
self._onRecordsLoaded(data);
//Call complete callback
if (completeCallback) {
completeCallback();
}
},
error: function () {
self._hideBusy();
self._showError(self.options.messages.serverCommunicationError);
}
});
}, 这段代码在jtable.js 390行开始。
这段代码中清楚的写道jtable加载数据的ajax函数，请仔细观察其中的 Result、Message、Records这三个变量首字符全是大写，而我们的程序的变量是小写。
也许有人会说我可以把我们的程序变量改为大写啊，但是问题出现了：
第一、不符合java代码编写风格，
第二、根本调试不通，在action中变量的set和get方法的下一个字母的大写，例如：
public Student getRecord() {
return record;
}
public void setRecord(Student record) {
this.record = record;
} 如果你将变量的首字符设置为大写，set和get方法的下一个字母也是大写，而struts2框架通过set和get获取变量的时候默认将变量的首字符设置成小写，所以你的首字母大写的变量不会传递到前台。（这部分应该是利用Java的反射机制，struts2并不知道你action中的私有变量，它是通过你公开的set和get方法获取的到你的变量）
解决的办法就是修改jtable.js的源码，通过我的测试只需用将相应的ajax函数中的 data.Result、data.Records 等在获取数据的地方修改即可，各位可以从我的附件中直接下载使用。
需要修改的数据有：
data.Result(7处修改);
data.Message(7处修改);
data.record(5处);
data.Records(2处修改);
data.Options(1处修改);
data.TotalRecordCount(1处修改)；
data.jtStartIndex(无需修改);
data.jtPageSize(无需修改);
五、附件
http://git.oschina.net/weisun826/jTable_Struts2_Demo