JavaEE基础——JavaBean和数据库元数据编程

目的：

编写一个访问MySql数据库的JavaBean，并编写database.jsp调用该javabean建立对数据库的连接，进行数据库元数据编程，database.jsp中采用如下输出形式给出该数据源的一些限制情况。

驱动名称	********
数据库的产品名称	********
数据库连接的URL	********
maxLen:	****
maxCharLiteralLen:	****
maxColumnsInTable:	****
maxRowSize:	****
maxConnections:	****
maxTablesInSelect:	****

程序代码：

DataBase.java
package beansrc;

import java.sql.*;

public class connectDB
{
	private Connection conn;
	private String url;
	private DatabaseMetaData dbmd;
	private String drivername;
	private String databaseproduct_name;
	private int maxLen;
	private int maxcharliteralLength;
	private int maxColumnsInTable;
	private int maxRowsize;
	private int maxConnections;
	private int maxTablesInSelect;
	
	public connectDB() throws Exception
	{
		Class.forName("com.mysql.jdbc.Driver");
		url="jdbc:mysql://localhost:3306/" +
				"testjdbc?useUnicode=true&characterEncoding=UTF-8";
		conn = DriverManager.getConnection(url, "root", "root");
		dbmd = conn.getMetaData();
		drivername = dbmd.getDriverName();
		databaseproduct_name = dbmd.getDatabaseProductName();
		maxLen = dbmd.getMaxIndexLength();
		maxcharliteralLength = dbmd.getMaxCharLiteralLength();
		maxColumnsInTable = dbmd.getMaxColumnsInTable();
		maxRowsize = dbmd.getMaxRowSize();
		maxConnections = dbmd.getMaxConnections();
		maxTablesInSelect = dbmd.getMaxTablesInSelect();
	}
	public String getDriverName()
	{
		return drivername;
	}
	public String getDatabaseproduct_name()
	{
		return databaseproduct_name;
	}
	public String getUrl()
	{
		return url;
	}
	public int getMaxLen()
	{
		return maxLen;
	}
	public int getMaxcharliteralLength()
	{ 
		return maxcharliteralLength;
	}
	public int getMaxColumnsInTable()
	{
		return maxColumnsInTable;
	}
	public int getMaxrowSize()
	{
		return maxRowsize;
	}
	public int getMaxconnections()
	{
			return maxConnections;		
	}
	public int getMaxTablesInselect()
	{
		return maxTablesInSelect;
	}
}
database.jsp
<%@ page contentType="text/html; charset=utf-8" language="java" import="java.sql.*" errorPage="" %>
<jsp:useBean id="connectDBBean" class="beansrc.connectDB" scope="page"/>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>test the JDBC</title>
<style type="text/css">
<!--
.STYLE1 {
	font-family: "楷体";
	font-weight: bold;
	font-size: 20px;
}
-->
</style>
</head>

<body>
<table width="41%" height="155" border="0" align="center" bordercolor="#FFFFFF">
  <tr>
    <td><table width="108%" border="1" bordercolor="#000000" style="border:#B7CBFF 1px; font-size:15px">
      <tr>
        <td colspan="2" align="center"><p class="STYLE1">数据源的一些限制情况</p></td>
        </tr>
      <tr>
        <td width="36%" align="center">驱动名称</td>
        <td width="64%" align="center" bgcolor="#FFFFFF"><%=connectDBBean.getDriverName()%></td>
      </tr>
      <tr>
        <td align="center">数据库的产品名称</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getDatabaseproduct_name()%></td>
      </tr>
      <tr>
        <td align="center">数据库连接的URL</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getUrl()%></td>
      </tr>
      <tr>
        <td align="center">maxLen:</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxLen()%></td>
      </tr>
      <tr>
        <td align="center">maxCharLiteralLen:</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxcharliteralLength()%></td>
      </tr>
      <tr>
        <td align="center">maxColumnsInTable:</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxColumnsInTable()%></td>
      </tr>
      <tr>
        <td align="center">maxRowSize: </td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxrowSize()%></td>
      </tr>
      <tr>
        <td align="center">maxConnections:</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxconnections()%></td>
      </tr>
      <tr>
        <td align="center">maxTablesInSelect:</td>
        <td align="center" bgcolor="#FFFFFF"><%=connectDBBean.getMaxTablesInselect()%></td>
      </tr>
      
    </table></td>
  </tr>
</table>


</body>
</html>

JavaEE基础——JavaBean和数据库元数据编程

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