db.java

本系统是用JSP技术开发

package pubTools;
import java.sql.*;
import javax.naming.*;
import javax.sql.DataSource;
import java.io.*;

public class db {
	
private Connection con;
private Statement stmt;
private ResultSet rs;

public db() {
	con = null;
	stmt = null;
	rs = null;
}
//定义结果集执行查询操作
public ResultSet executeQuery(String sql) {
	rs = null;
	try {
		Context initCtx = new javax.naming.InitialContext();
		Context envCtx = (Context)initCtx.lookup("java:comp/env");
		DataSource ds = (DataSource)envCtx.lookup("jdbc/kcsj");		
		con = ds.getConnection();
		stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
		//数据库连接
		rs = stmt.executeQuery(sql);
	 //将SQL执行查询操作结果，存到rs}
	catch(NamingException  ex) {
		System.err.println("db.lookupName: " + ex.getMessage());
	}	
	catch(SQLException ex) {
		System.err.println("db.executeQuery: " + ex.getMessage());
	}
	return rs;
	// 返回所请求的页面
}

public void executeUpdate(String sql) {
	try {
		Context initCtx = new javax.naming.InitialContext();
		Context envCtx = (Context)initCtx.lookup("java:comp/env");
		DataSource ds = (DataSource)envCtx.lookup("jdbc/kcsj");		
		con = ds.getConnection();
		stmt = con.createStatement();
		stmt.executeUpdate(sql);
		stmt.close();
		con.close();
	}
	catch(NamingException  ex) {
		System.err.println("db.lookupName: " + ex.getMessage());
	}	
	catch(SQLException ex) {
		System.err.println("db.executeUpdate:" + ex.getMessage());
	}
}

public void closeCon(){
	if(rs != null){
		try{
			rs.close();
		}catch(SQLException e){e.printStackTrace();}
		rs = null;
	}
	if(stmt != null){
		try{
			stmt.close();
		}catch(SQLException e){e.printStackTrace();}
		stmt = null;
	}
	if(con != null){
		try{
			con.close();
		}catch(SQLException e){e.printStackTrace();}
		con = null;
	}
}
//用来显示中文字体；
public String getStr(String str) {
	try {
		String temp_p=str;
		byte[] temp_t=temp_p.getBytes("ISO8859-1");
		String temp=new String(temp_t);
		return temp;
	}
	catch(Exception e) {
		e.printStackTrace();
	}
	return "null";
}

}