Ajax入门实例结合struts2

package com.impl; import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.dao.UserDao; import com.entity.User; public class UserImpl implements UserDao { /* (non-Javadoc) * @see com.impl.UserDao#add(com.entity.User) */ public void add(User user){ Connection conn=null; PreparedStatement ps=null; try{ Class.forName("oracle.jdbc.driver.OracleDriver"); conn=DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:XE","system","890216"); String sql="insert into t_user values(?,?,?)"; ps=conn.prepareStatement(sql); ps.setInt(1, user.getId()); ps.setString(2,user.getName() ); ps.setString(3, user.getPassword()); ps.executeUpdate(); }catch(Exception e){ e.printStackTrace(); }finally{ try { if(ps!=null){ps.close();} if(conn!=null){conn.close();} } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /* (non-Javadoc) * @see com.impl.UserDao#findall() */ public List<User> findall(){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; List list =new ArrayList<User>(); try{ Class.forName("oracle.jdbc.driver.OracleDriver"); conn=DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:XE", "system","890216"); String sql="select * from t_user"; ps=conn.prepareStatement(sql); rs=ps.executeQuery(); while(rs.next()){ User user=new User(); user.setId(rs.getInt(1)); user.setName(rs.getString(2)); user.setPassword(rs.getString(3)); list.add(user); } }catch(Exception e){ e.printStackTrace(); }finally{ try { if(rs!=null){rs.close();} if(ps!=null){ps.close();} if(conn!=null){conn.close();} } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return list; } public boolean isName(String name){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; boolean f=false; try{ Class.forName("oracle.jdbc.driver.OracleDriver"); conn=DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:XE", "system", "890216"); String sql="select * from t_user where name=?"; ps=conn.prepareStatement(sql); ps.setString(1, name); rs=ps.executeQuery(); if(rs.next()){ f=true; return f; } }catch(Exception e){ e.printStackTrace(); }finally{ try { if(rs!=null){rs.close();} if(ps!=null){ps.close();} if(conn!=null){conn.close();} } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return f; } public static void main(String[] args) { UserDao ui=new UserImpl(); // User user=new User(); // user.setId(1); // user.setName("qqq"); // user.setPassword("1234"); // ui.add(user); System.out.println(ui.findall()); } }