?? getdbinfoservlet2.java
字號:
package org.sunxin.lesson.jsp.bookstore;
import javax.servlet.*;
import java.io.*;
import javax.servlet.http.*;
import java.sql.*;
import java.util.ArrayList;
import javax.sql.*;
import javax.naming.*;
public class GetDBInfoServlet2 extends HttpServlet
{
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException,IOException
{
Connection conn=null;
Statement stmt=null;
ResultSet rs=null;
try
{
Context ctx=new InitialContext();
DataSource ds=(DataSource)ctx.lookup("java:comp/env/jdbc/bookstore");
conn=ds.getConnection();
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
out.println("<html><head>");
out.println("<title>數據庫表的信息</title>");
out.println("</head><body>");
String tableName=req.getParameter("tableName");
if(null==tableName || tableName.equals(""))
{
DatabaseMetaData dbMeta=conn.getMetaData();
rs=dbMeta.getTables(null,null,null,new String[]{"TABLE"});
out.println("<form action=\"getdbinfo\" method=\"get\">");
out.println("<select size=1 name=tableName>");
while(rs.next())
{
out.println("<option value="+rs.getString("TABLE_NAME")+">");
out.println(rs.getString("TABLE_NAME"));
out.println("</option>");
}
out.println("</select><p>");
out.println("<input type=\"submit\" value=\"提交\">");
out.println("</form>");
}
else
{
stmt=conn.createStatement();
rs=stmt.executeQuery("select * from "+tableName);
ResultSetMetaData rsMeta=rs.getMetaData();
int columnCount=rsMeta.getColumnCount();
out.println("<table border=1>");
out.println("<caption>表的結構</catption>");
out.println("<tr><th>字段名</th><th>字段類型</th><th>最大字符寬度</th></tr>");
ArrayList<String> al=new ArrayList<String>();
for(int i=1;i<=columnCount;i++)
{
out.println("<tr>");
String columnName=rsMeta.getColumnName(i);
out.println("<td>"+columnName+"</td>");
al.add(columnName);
out.println("<td>"+rsMeta.getColumnTypeName(i)+"</td>");
out.println("<td>"+rsMeta.getColumnDisplaySize(i)+"</td>");
}
out.println("</table><p>");
out.println("<table border=1>");
out.println("<caption>表中的數據</catption>");
out.println("<tr>");
for(int i=0;i<columnCount;i++)
{
out.println("<th>"+al.get(i)+"</th>");
}
while(rs.next())
{
out.println("<tr>");
for(int i=1;i<=columnCount;i++)
{
out.println("<td>"+rs.getString(i)+"</td>");
}
out.println("</tr>");
}
out.println("</table>");
}
out.println("</body><html>");
out.close();
}
catch(NamingException ne)
{
ne.printStackTrace();
}
catch(SQLException se)
{
se.printStackTrace();
}
finally
{
if(rs!=null)
{
try
{
rs.close();
}
catch(SQLException se)
{
se.printStackTrace();
}
rs=null;
}
if(stmt!=null)
{
try
{
stmt.close();
}
catch(SQLException se)
{
se.printStackTrace();
}
stmt=null;
}
if(conn!=null)
{
try
{
conn.close();
}
catch(SQLException se)
{
se.printStackTrace();
}
conn=null;
}
}
}
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