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JSP 2.0 + ORACLE 9i 下高效率分页的一个例子

王朝java/jsp·作者佚名  2006-01-09
窄屏简体版  字體: |||超大  

package com.cwbnig;

import java.sql.Connection;

import java.sql.SQLException;

import javax.sql.DataSource;

import javax.naming.Context;

import javax.naming.InitialContext;

import javax.naming.NamingException;

public class DatabaseConn

{

public DatabaseConn()

{

}

public static synchronized Connection getConnection()throws Exception

{

Connection conn = null;

try

{

Context initCtx=new InitialContext();

Context envCtx=(Context)initCtx.lookup("java:comp/env");

DataSource ds=(DataSource)envCtx.lookup("jdbc/jspdev");

return ds.getConnection();

}

catch(SQLException e)

{

throw e;

}

catch(NamingException e)

{

throw e;

}

}

}

package com.cwbnig;

import java.sql.*;

import java.util.Vector;

public class OperateDB

{

private Connection conn=null;

private Statement stmt=null;

PreparedStatement pstmt=null;

CallableStatement cstmt=null;

private ResultSet rs=null;

private ResultSetMetaData rsmd=null;

private String strsql="";

public OperateDB()

{

try

{

conn = DatabaseConn.getConnection();

}

catch (Exception e)

{

System.out.println("Error:com.cwbnig.OperateDB:Structure Method");

}

}

public Connection getConnection() throws SQLException

{

return this.conn;

}

public ResultSet executeQuery(String sql) throws SQLException

{

stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);

return stmt.executeQuery(sql);

}

public ResultSet listDataFromMSSQL(int curpage,int pagesize,String tablename,String sid,String con,String order) throws SQLException

{

int SELECTNUM=(curpage-1)*pagesize+1;

if(order.equalsIgnoreCase("asc"))

{

String min="SELECT MAX("+sid+") AS id FROM (SELECT TOP "+SELECTNUM+" "+sid+" FROM "+tablename+" ORDER BY "+sid+" ASC) tbl";

strsql="SELECT TOP "+pagesize+" * FROM "+tablename+" WHERE "+sid+" >="+min+con+" ORDER BY "+sid+" ASC";

}

else

{

String max="SELECT MIN("+sid+") AS id FROM (SELECT TOP "+SELECTNUM+" "+sid+" FROM "+tablename+" ORDER BY "+sid+" DESC) tbl";

strsql="SELECT TOP "+pagesize+" * FROM "+tablename+" WHERE "+sid+" <="+max+con+" ORDER BY "+sid+" DESC";

}

return this.executeQuery(strsql);

}

public ResultSet listDataFromMySQL(int curpage,int pagesize,String tablename,String sid,String con,String order) throws SQLException

{

int SELECTNUM=(curpage-1)*pagesize;

if(order.equalsIgnoreCase("asc"))

{

strsql="SELECT * FROM "+tablename+con+" ORDER BY "+sid+" ASC LIMIT "+SELECTNUM+","+pagesize;

}

else

{

strsql="SELECT * FROM "+tablename+con+" ORDER BY "+sid+" DESC LIMIT "+SELECTNUM+","+pagesize;

}

return this.executeQuery(strsql);

}

public ResultSet listDataFromOracle(int curpage,int pagesize,String tablename,String sid,String con,String order) throws SQLException

{

int SELECTNUM=(curpage-1)*pagesize+2;

if(order.equalsIgnoreCase("asc"))

{

String min="SELECT MAX("+sid+") AS SID FROM (SELECT "+sid+" FROM "+tablename+" WHERE ROWNUM <"+SELECTNUM+" ORDER BY "+sid+" ASC) TBL";

strsql="SELECT * FROM "+tablename+" WHERE "+sid+" >=("+min+") AND ROWNUM <"+(pagesize+1)+con+" ORDER BY "+sid+" ASC";

}

else

{

String max="SELECT MIN("+sid+") AS SID FROM (SELECT "+sid+" FROM "+tablename+" WHERE ROWNUM <"+SELECTNUM+" ORDER BY "+sid+" DESC) TBL";

strsql="(SELECT * FROM "+tablename+" WHERE "+sid+" <=("+max+") ORDER BY "+sid+" DESC)TBL2";

strsql="SELECT * FROM "+strsql+" WHERE ROWNUM<"+(pagesize+1)+con;

}

return this.executeQuery(strsql);

}

public Vector getDataFromMSSQL(int curpage,int pagesize,String tablename,String sid,String con,String order) throws Exception

{

Vector v=new Vector();

rs=this.listDataFromMSSQL(curpage,pagesize,tablename,sid,con,order);

rsmd=rs.getMetaData();

int colnum=rsmd.getColumnCount();

while(rs.next())

{

Object[] obj=new Object[colnum];

for(int i=0;i<colnum;i++)

{

obj[i]=new String(this.getCol(rs,rsmd.getColumnType(i+1),i+1));

}

v.add(obj);

}

stmt.close();

rs.close();

conn.close();

return v;

}

public Vector getDataFromMySQL(int curpage,int pagesize,String tablename,String sid,String con,String order) throws Exception

{

Vector v=new Vector();

rs=this.listDataFromMySQL(curpage,pagesize,tablename,sid,con,order);

rsmd=rs.getMetaData();

int colnum=rsmd.getColumnCount();

while(rs.next())

{

Object[] obj=new Object[colnum];

for(int i=0;i<colnum;i++)

{

obj[i]=new String(this.getCol(rs,rsmd.getColumnType(i+1),i+1));

}

v.add(obj);

}

stmt.close();

rs.close();

conn.close();

return v;

}

public Vector getDataFromOracle(int curpage,int pagesize,String tablename,String sid,String con,String order) throws Exception

{

Vector v=new Vector();

rs=this.listDataFromOracle(curpage,pagesize,tablename,sid,con,order);

rsmd=rs.getMetaData();

int colnum=rsmd.getColumnCount();

while(rs.next())

{

Object[] obj=new Object[colnum];

for(int i=0;i<colnum;i++)

{

obj[i]=new String(this.getCol(rs,rsmd.getColumnType(i+1),i+1));

}

v.add(obj);

}

stmt.close();

rs.close();

conn.close();

return v;

}

public String getCol(ResultSet rs,int type,int colNum)throws Exception

{

String ret="";

switch(type)

{

case(1):ret=rs.getString(colNum);break;

case(2):ret=rs.getString(colNum);break;

case(4):ret=String.valueOf(rs.getInt(colNum));break;

case(5):ret=String.valueOf(rs.getInt(colNum));break;

case(6):ret=String.valueOf(rs.getFloat(colNum));break;

case(8):ret=String.valueOf(rs.getDouble(colNum));break;

case(12):ret=rs.getString(colNum);break;

default:ret="not know";

}

return ret;

}

public Object[] getColName(String tablename)throws Exception

{

stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);

rs=stmt.executeQuery("SELECT * FROM "+tablename+" WHERE ROWNUM<2");

rsmd=rs.getMetaData() ;

int colnum=rsmd.getColumnCount();

Object[] obj=new Object[colnum];

for(int i=0;i<colnum;i++)

{

obj[i]=rsmd.getColumnName(i+1);

}

return obj;

}

public int getRowCount(String tablename) throws SQLException

{

stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);

strsql="SELECT COUNT(*) AS COUNT FROM "+tablename;

rs=stmt.executeQuery(strsql);

if(rs.next())

{

return rs.getInt(1);

}

else

{

return 0;

}

}

public int getRowCount(ResultSet rs) throws SQLException

{

int rowCount = 0;

rs.last();

rowCount = rs.getRow();

rs.beforeFirst();

return rowCount;

}

public int executeUpdate(String sql) throws SQLException

{

stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);

return stmt.executeUpdate(sql);

}

public int[] executeUpdateBatch(String[] sqls) throws SQLException

{

conn.setAutoCommit(false);

stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);

try

{

for (int i = 0; i < sqls.length; i++)

{

stmt.addBatch(sqls[i]);

}

int[] updateCounts=stmt.executeBatch();

conn.commit();

conn.setAutoCommit(true);

return updateCounts;

}

catch (SQLException e)

{

conn.rollback();

throw e;

}

}

public PreparedStatement prepareStatement(String sql) throws SQLException

{

pstmt = conn.prepareStatement(sql);

return pstmt;

}

public CallableStatement callableStatement(String sql) throws SQLException

{

cstmt = conn.prepareCall(sql);

return cstmt;

}

public void setAutoCommit(boolean s) throws SQLException

{

conn.setAutoCommit(s);

}

public void commit() throws SQLException

{

conn.commit();

}

public void rollback() throws SQLException

{

conn.rollback();

}

public void close() throws SQLException

{

if (stmt != null)

{

stmt.close();

stmt = null;

}

if (conn != null)

{

conn.close();

conn = null;

}

}

}

<%@ page contentType="text/html; charset=gb2312" language="java" errorPage="errorinfo.jsp"%>

<html>

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=gb2312">

<title>testOracle</title>

</head>

<body>

<jsp:useBean id="operatedb" scope="page" class="com.cwbnig.OperateDB"/>

<%

Object[] obj=null;

obj=operatedb.getColName("TBL_STRUCTS");

for(int temp=0;temp<obj.length;temp++)

{

out.println(obj[temp]);

}

out.println("<br>");

java.util.Vector v=operatedb.getDataFromOracle(1,10,"TBL_STRUCTS","SID","","desc");

java.util.Enumeration e=v.elements();

while(e.hasMoreElements())

{

obj=(Object[])e.nextElement();

for(int i=0;i<obj.length;i++)

{

out.println(obj[i]);

}

out.print("<br>");

}

%>

</table>

<br>

<a href="testOracle.do?forward=bdgk">testOracle.do?forward=bdgk</a>

</body>

</html>

 
 
 
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