使用ExtJs 来显示数据，并实现数据的分页功能

既然刚刚已经学到了使用ajax来异步请求后台数据库得到json数据，那几今天就跳转到Extjs，也是一个强大的javascript库，之所以强大，完全是因为他提供了一套实用ui界面，其中最常用的显示控件就是gridPanel ，所以今天就学习一下怎样使用gridPanel来完成数据的分页显示。

1，首先定义好用来显示的实体：

package edu.hue.jk.bean;

import javax.persistence.*;

@Entity
@Table(name="tb_book")
public class Book {
	private int bookId;
	private String bookName;
	private String bookAuthor;
	private double bookPrice;
	@Id
	@GeneratedValue
	@Column(name="book_id")
	public int getBookId() {
		return bookId;
	}
	@Column(name="book_name")
	public String getBookName() {
		return bookName;
	}
	@Column(name="book_author")
	public String getBookAuthor() {
		return bookAuthor;
	}
	@Column(name="book_price")
	public double getBookPrice() {
		return bookPrice;
	}
	public void setBookId(int bookId) {
		this.bookId = bookId;
	}
	public void setBookName(String bookName) {
		this.bookName = bookName;
	}
	public void setBookAuthor(String bookAuthor) {
		this.bookAuthor = bookAuthor;
	}
	public void setBookPrice(double bookPrice) {
		this.bookPrice = bookPrice;
	}
	public Book() {
		super();
		// TODO Auto-generated constructor stub
	}
	public Book(String bookName, String bookAuthor, double bookPrice) {
		super();
		this.bookName = bookName;
		this.bookAuthor = bookAuthor;
		this.bookPrice = bookPrice;
	}
	
	
}

2，使用Hibernate 实现数据库的相关操作，这里只做了总数查询和 分页查询

import java.sql.SQLException;
import java.util.LinkedList;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import edu.hue.jk.bean.Book;
public class BookDao extends HibernateDaoSupport{  // 添加分页查询的功能
	public void addBook(Book book){
		getHibernateTemplate().save(book);
		
	}
	/***
	 * 得到所有图书的数目
	 * @return
	 */
	public long getBookNunber(){  
		return (Long)getHibernateTemplate().find(" select Count(*) from Book").get(0);
		
	}
	public List getBookByPage( final int start,final int page, final int limit){
		List books=new LinkedList();
		books=getHibernateTemplate().executeFind(new HibernateCallback