java 增删改查小实例

package com.cn.app; import java.sql.Statement; import java.sql.Connection; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import com.cn.db.DBConnection; public class Query { public Connection conn; public Statement st ; public ResultSet rs ; DBConnection db = new DBConnection(); /* * 验证用户信息 */ public boolean getNameAsPwd(String sQuery)throws Exception { boolean flag = false; conn = db.getConnection(); st = conn.createStatement(); rs = st.executeQuery(sQuery); if(rs.next()){ flag = true; } return flag; } /* * 查询用户信息 */ public List allQuery(String sql) { List userList = new ArrayList(); try{ conn = db.getConnection(); st = conn.createStatement(); rs = st.executeQuery(sql); userBean ub = null; while(rs.next()) { ub = new userBean(); ub.setId(rs.getInt("id")); ub.setName(rs.getString("name")); ub.setPwd(rs.getString("pwd")); userList.add(ub); } }catch(Exception e) { e.printStackTrace(); } return userList; } /* * 增 删 改 */ public boolean UpUser(String sql)throws Exception { boolean flag = false; try{ st = db.getConnection().createStatement(); st.execute(sql); return true; }catch(Exception e) { e.printStackTrace(); }finally{ if(conn!=null) { conn.close(); } if(st!=null) { st.close(); } if(rs!=null) { rs.close(); } } return flag; } }