从数据库中读取数据后的显示问题

[sadls]

我在bean中写了一个查询多条数据的方法，用的ArrayList。现在的问题是，集合中有很多从库中查出来的title字段的内容，但我想在页面中的某个地方只显示id为1的title字段的内容，这个如何实现？
还有就是，我又写了一个查询一条数据的方法，代码如下：

public book find(int id){
		Connection conn=linkDB();
		String sql="select * from p where id="+id;
		Statement stmt;
		book b=new book();
		try {
			stmt = (Statement)conn.createStatement();
			ResultSet rs=stmt.executeQuery(sql);
			rs.next();
				
			b.setTitle1(rs.getString("title1"));
			b.setTitle2(rs.getString("title2"));
			b.setImage(rs.getString("image"));
			b.setContent(rs.getString("content"));
			b.setPrice(rs.getInt("price"));
			} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			closeDB(conn);
		}
		return b;
	}

我在页面中是这么写的，<% dbControl db = new dbControl(); %><% db.find(1).getTitle1(); %>，我是想显示出id为1的title1字段的内容，但挂上TOMCAT后db.find(1).getTitle1(); 这句报错了，我哪里写的不对请帮忙指正，谢~~

[sadls]

哈 解决了
连库方法里应该是return conn,我给写成return null造成了错误。

[eswn]

把错误日志贴上来吧。可能出错的地方太多了。

[Kevin-Kung]

你先仔细看下是报的什么错误...看起来是没错。有可能是牵扯到其他的页面

[sadls]

晕了...报错又变了
我把所有代码和错误日志都贴上来，大侠帮忙看一眼吧~

[sadls]

package bean2;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import bean2.book;

public class dbControl {
	/*连接数据库*/
	public Connection linkDB()
	{
		Connection conn=null;
		try 
		{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
			conn=DriverManager.getConnection("jdbc:odbc:book");
		}
		catch (Exception e) 
		{
			e.printStackTrace();
		} 
		return null;
	}
	
	/*查询多条数据*/
	public ArrayList list()
	{
		Connection conn=linkDB();
		String sql="select * from p";
		ArrayList list=new ArrayList();
		Statement stmt = null;
		try {
			stmt=(Statement)conn.createStatement();
		} catch (SQLException e) {
			
			e.printStackTrace();
		}
		ResultSet rs = null;
		try {
			rs = stmt.executeQuery(sql);
		} catch (SQLException e) {
			
			e.printStackTrace();
		}
		try {
			while(rs.next())
			{
				book b=new book();
				b.setId(rs.getInt("id"));
				b.setTitle1(rs.getString("title1"));
				b.setTitle2(rs.getString("title2"));
				b.setImage(rs.getString("image"));
				b.setContent(rs.getString("content"));
				b.setPrice(rs.getInt("price"));
				list.add(b);
			}
		} catch (SQLException e) {
			
			e.printStackTrace();
		}
		return list;
	}
	
	/*查找一条记录*/
	public book find(int id){
		Connection conn=linkDB();
		String sql="select * from p where id="+id;
		Statement stmt;

		book b=new book();
		try {
			stmt = (Statement)conn.createStatement();
			ResultSet rs=stmt.executeQuery(sql);
			rs.next();
				
			b.setTitle1(rs.getString("title1"));
			b.setTitle2(rs.getString("title2"));
			b.setImage(rs.getString("image"));
			b.setContent(rs.getString("content"));
			b.setPrice(rs.getInt("price"));

		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			closeDB(conn);
		}
		return b;
	}
	
	/*关闭数据库*/
	public void closeDB(Connection conn)
	{
		try 
		{
			conn.close();
		} 
		catch (SQLException e) 
		{
			e.printStackTrace();
		}
	}
	
}

package bean2;

public class book {
	String title1;
	String title2;
	String image;
	String content;
	int id;
	int price;
	public String getTitle1() {
		return title1;
	}
	public void setTitle1(String title1) {
		this.title1 = title1;
	}
	public String getTitle2() {
		return title2;
	}
	public void setTitle2(String title2) {
		this.title2 = title2;
	}
	public String getImage() {
		return image;
	}
	public void setImage(String image) {
		this.image = image;
	}
	public String getContent() {
		return content;
	}
	public void setContent(String content) {
		this.content = content;
	}
	public int getPrice() {
		return price;
	}
	public void setPrice(int price) {
		this.price = price;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
}

[sadls]

错误日志如下：

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:541)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


root cause

java.lang.NullPointerException
bean2.dbControl.closeDB(dbControl.java:99)
bean2.dbControl.find(dbControl.java:89)
org.apache.jsp.index1_jsp._jspService(index1_jsp.java:134)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


note The full stack trace of the root cause is available in the Apache Tomcat/6.0.14 logs.

[eswn]

这里面可能是你的数据库连接取得失败，这句打断点：
conn=DriverManager.getConnection("jdbc:odbc:book");
conn是不是为空？

[sadls]

5555555
恕我愚笨，刚会使用MyEclipse不久，断点之类的还不怎么会使用。=.=||