java使用三层架构实现电影购票系统

import java.lang.reflect.field;

import java.sql.connection;

import java.sql.drivermanager;

import java.sql.preparedstatement;

import java.sql.resultset;

import java.sql.resultsetmetadata;

import java.sql.sqlexception;

import java.util.arraylist;

import java.util.list;

public class basedao {

  public static final string driver = "com.mysql.jdbc.driver" ;

  public static final string url = "jdbc:mysql://localhost:3306/tickets" ;

  // 加载驱动，只需加载一次

  static {

  try {

  class .forname(driver);

  } catch (classnotfoundexception e) {

  // todo auto-generated catch block

  e.printstacktrace();

  }

  }

  // 获得连接

  public connection getconn() {

  connection conn = null ;

  try {

  conn = drivermanager.getconnection(url, "root" , "123456" );

  } catch (sqlexception e) {

  // todo auto-generated catch block

  e.printstacktrace();

  }

  return conn;

  }

  // 关闭所有

  public void releaseall(resultset rs, preparedstatement pstmt, connection conn) {

  try {

  if (rs != null ) {

  rs.close();

  }

  if (pstmt != null ) {

  pstmt.close();

  }

  if (conn != null ) {

  conn.close();

  }

  } catch (sqlexception e) {

  // todo auto-generated catch block

  e.printstacktrace();

  }

  }

  // 增删改 封装

  public boolean operupdate(string sql, list<object> params) {

  connection conn = null ;

  preparedstatement pstmt = null ;

  int res = 0 ;

  // 获得与数据库的连接对象

  conn = getconn();

  try {

  pstmt = conn.preparestatement(sql);

  if (params != null ) {

  for ( int i = 0 ; i < params.size(); i++) {

  pstmt.setobject(i + 1 , params.get(i));

  }

  }

  // 增刪改的統一方法

  res = pstmt.executeupdate();

  //返回的是sql在数据库中影响的行数

  } catch (sqlexception e) {

  // todo auto-generated catch block

  e.printstacktrace();

  } finally {

  releaseall( null , pstmt, conn);

  }

  return res > 0 ? true : false ;

  }

  public <t> list<t> operquery(string sql, list<object> params, class <t> cls) throws exception {

  connection conn = null ;

  preparedstatement pstmt = null ;

  resultset rs = null ;

  list<t> list = new arraylist<t>();

  conn = getconn();

  try {

  pstmt = conn.preparestatement(sql);

  if (params != null ) {

  for ( int i = 0 ; i < params.size(); i++) {

  pstmt.setobject(i + 1 , params.get(i));

  }

  }

  // 增刪改的統一方法

  rs = pstmt.executequery();

  resultsetmetadata rsmd = rs.getmetadata();

  while (rs.next()) {

  t m = cls.newinstance();

  for ( int i = 0 ; i < rsmd.getcolumncount(); i++) {

  string col_name = rsmd.getcolumnname(i + 1 );

  object value = rs.getobject(col_name);

  field field;

  field = cls.getdeclaredfield(col_name);

  field.setaccessible( true );

  field.set(m, value);

  }

  list.add(m);

  }

  }

  catch (sqlexception e) {

  // todo auto-generated catch block

  e.printstacktrace();

  } finally {

  releaseall(rs, pstmt, conn);

  }

  return list;

  }

}