数据连接池dao 优化

} catch (IOException e) {
e.printStackTrace();
}
}
private static synchronized void makeinstance(){
if(instance==null){
instance=new Env();
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
throws ServletException, IOException {
doPost(request,response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
response.sendRedirect("display.jsp");
}
}
取数据jsp
<bLeabharlann dy> <%ArrayList list=(ArrayList)session.getAttribute("list");
System.out.println(list);
ds.setPassword(Env.getInstance().getProperty("oracle_password"));
ds.setUrl(Env.getInstance().getProperty("oracle_url"));
ds.setInitialSize(5);
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html");
ds.setMinIdle(10);
ds.setMaxIdle(100);
ds.setMaxActive(1000);
try {
conn=ds.getConnection();
} catch (SQLException e) {
e.printStackTrace();
PrintWriter out = response.getWriter();
HttpSession session=request.getSession();
List list=new ArrayList();
DBHelper db = new DBHelper();
Connection conn = db.getConn();
import java.sql.SQLException;
import mons.dbcp.BasicDataSource;
public class DBHelper {
public Connection getConn(){
Connection conn=null;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
首先加载三个驱动
oracle 驱动
dbcp驱动
pool驱动
db.properties
oracle_username=scott
oracle_password=scott
oracle_driverclass=oracle.jdbc.driver.OracleDriver
oracle_url=jdbc\:oracle\:thin\:@localhost\:1521\:orcl
Iterator<String> it=list.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
%>
</body>
}
return conn;
}
public void queryDatabase(){
}
}
查询数据的servlet
package com.icss;
import java.io.IOException;
import java.io.PrintWriter;
ResultSet rs = (ResultSet)ps.getObject(1);
while(rs.next()){
String s=rs.getString(1);
list.add(s);
}
session.setAttribute("list", list);
env.java
package com.icss;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class Env extends Properties {
import javax.servlet.http.HttpSession;
public class QueryDatabase extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
} catch (SQLException e) {
e.printStackTrace();
}
System.out.println("xiaoge");
// request.getRequestDispatcher("display.jsp").forward(request, response);
}
}
public static Env getInstance(){
if(instance==null){
makeinstance();
}
return instance;
}
}
DBHelper.java
package com.icss;
import java.sql.Connection;
try {
CallableStatement ps = conn.prepareCall("{ call p1(?)}");
ps.registerOutParameter(1,oracle.jdbc.OracleTypes.CURSOR);
ps.execute();
private static Env instance;
private Env(){
InputStream inputstream=getClass().getResourceAsStream("/db.properties");
try {
this.load(inputstream);
BasicDataSource ds=new BasicDataSource();
ds.setDriverClassName(Env.getInstance().getProperty("oracle_driverclass"));
ds.setUsername(Env.getInstance().getProperty("oracle_username"));