Java Summary (essay)--code summary JDBC and transaction, take bank transfer, audit, etc. for example

This article is a functional extension of the example of a transaction in the previous article to deepen understanding and code proficiency:
(1) Database tables

Data:

(2) Introduction of database connection Jar Package
(3) Tool type:

Package Org.jdbc.util;import Java.io.file;import Java.io.fileinputstream;import java.io.inputstream;import Java.sql.connection;import Java.sql.drivermanager;import Java.sql.resultset;import Java.sql.SQLException;import    Java.sql.statement;import java.util.properties;//Operation Database Tool class public class Dbutil {//Privatization construction Method Private Dbutil () {}    private static String URL = null;    private static String user = null;    private static String password = NULL;            static {try {Class.forName ("com.mysql.jdbc.Driver");            Properties Pro = new properties ();            Pro.load (New FileInputStream ("Src/jdbc.properties"));            url = pro.getproperty ("url");            user = Pro.getproperty ("user");        Password = pro.getproperty ("password");        } catch (Exception e) {e.printstacktrace (); }}//Read external properties file to get Connection object, manually enter URL public static Connection getConnection1 (String URL) {Properties pro = new        Properties (); ConnectiOn conn = null;        InputStream input = null;            try {input = new FileInputStream ("E:" + file.separator + "jdbc.properties");            Pro.load (input);        conn = drivermanager.getconnection (URL, pro);        } catch (Exception e) {e.printstacktrace ();    } return conn;  }//Read the configuration file under the project, get the Connection object parameters, do not need to manually enter the URL public static Connection GetConnection2 () throws SQLException {Connection        conn = drivermanager.getconnection (URL, user, password);    Return conn; }//Release all resources public static void CloseAll (Connection conn, Statement Stat, ResultSet rs) throws Sqlexceptio        n {if (conn! = null) {conn.close ();        } if (stat! = null) {stat.close ();        } if (rs! = null) {rs.close ();        }}//Release the resource used public static void Closepart (Connection conn, Statement Stat) throws SQLException {      IF (conn! = null) {      Conn.close ();        } if (stat! = null) {stat.close (); }    }}

(4) Writing code:

Package Org.jdbc.transcation;import Java.io.bufferedreader;import Java.io.ioexception;import Java.io.inputstreamreader;import Java.sql.connection;import Java.sql.preparedstatement;import Java.sql.ResultSet; Import Java.sql.sqlexception;import Java.util.scanner;import Org.jdbc.util.dbutil;public class AccountDemo {//Main method control operation Row direction public static void main (string[] args) {BufferedReader br = new BufferedReader (New InputStreamReader (System        . in));        Scanner scan = new Scanner (system.in);        System.out.println ("Welcome to the analog banking interface");            while (true) {System.out.print ("Please enter your choice (1 Transfer 2 Enquiry 3 Deposit 4 Withdrawals 5 account opening 8 exit):");            int chioce;                try {chioce = Scan.nextint ();                    if (Chioce = = 1 | chioce = = 2 | chioce = 3 | chioce==4 | chioce==5 |CHIOCE = 8) {switch (CHIOCE) {                        Case 1://Transfer System.out.print ("Please enter the name of the transfer account:");    String fromname = Br.readline ();                    System.out.print ("Please enter the account name:");                        String toname = Br.readline ();                        System.out.print ("Please enter the transfer amount:");                        int money = Scan.nextint ();                        Boolean flag = TransferMoney (FromName, ToName, money);                            if (flag) {System.out.println ("successful transfer");                            Showbalance (ToName);                        Showbalance (FromName); } else {System.out.println ("Please check that you entered the correct information, please enter the correct information, re-handle this business, thank you!")                        ");                    } break;                        Case 2://Query System.out.print ("Please select (1: Check all account information \t2: Personal account Information):");                        int chioce1 = Scan.nextint (); if (Chioce1 = = 1 | chioce1 = = 2) {switch (CHIOCE1) {Case 1://Query full  Department account SelectAll ();                              Break                                Case 2://Enquiry for Personal account System.out.print ("Please enter enquiry account name:");                                String balname = Br.readline ();                                Selectpart (Balname);                            Break                        }} else {System.out.println ("Your options are wrong, please re-enter");                    } break;                        Case 3://Deposit System.out.print ("Please enter deposit account name:");                        String savname = Br.readline ();                        System.out.print ("Please enter Deposit Amount:");                        int Savmoney = Scan.nextint ();                        Boolean issave = Savemoney (Savname, Savmoney);                            if (issave) {System.out.println ("deposit success");                        Showbalance (Savname); } else {SystEm.out.println ("The account information you entered is incorrect, the deposit failed.");                    } break;                        Case 4://Withdrawal System.out.print ("Please enter the withdrawal account name:");                        String draname = Br.readline ();                        System.out.print ("Please enter the withdrawal amount:");                        int Dramoney = Scan.nextint ();                        Boolean isdraw = Drawmoney (Draname, Dramoney);                            if (Isdraw) {System.out.println ("withdrawal success");                        Showbalance (Draname);                        } else {System.out.println ("The account information you entered is incorrect, the withdrawal failed.");                    } break;                        Case 5://Withdrawal System.out.print ("Please Enter account name:");                        String opname = Br.readline ();                        System.out.print ("Please enter account opening deposit amount:");                        int opbalance = Scan.nextint (); Boolean isOpen =Openaccount (Opname, opbalance);                            if (IsOpen) {System.out.println ("Congratulations, successful account opening");                            System.out.println ("Current account information:");                        Selectpart (Opname);                        } else {System.out.println ("Sorry, an exception occurred, you failed to open an account.");                    } break; Case 8://Exit the system System.out.println ("Thank You for coming, goodbye!!")                        ");                    System.exit (0);                }} else {System.out.println ("Your options are wrong, please re-enter");            }} catch (IOException e) {System.out.println ("you have an illegal operation that produces an abnormal phenomenon:" +e.getmessage ());  }}}//Turn Money Method @SuppressWarnings ("resource") public static Boolean TransferMoney (String FromName, String        ToName, int money) {Boolean flag = false;        PreparedStatement PS = null; Connection conn =Null        ResultSet Rs=null;            try {conn = Dbutil.getconnection2 ();            String sql= "SELECT * from account where name=?";            Ps=conn.preparestatement (SQL);            Ps.setstring (1, fromname);            Rs=ps.executequery ();            Boolean flag1=false;            Flag1= Rs.next ();            Ps.close ();            Ps=conn.preparestatement (SQL);            Ps.setstring (1, fromname);            Rs=ps.executequery ();            Boolean flag2=false;            Flag2= Rs.next ();            Ps.close (); if ((Flag1 && flag2)!=false) {Conn.setautocommit (false);//Cancel autocommit String sql1 = "Upda Te account set balance=balance-?                where name=? "; String sql2 = "Update account set balance=balance+?"                where name=? ";                PS = conn.preparestatement (SQL1);                Ps.setint (1, money);                Ps.setstring (2, fromname);//Turn out ps.executeupdate ();  Ps.close ();              PS = conn.preparestatement (SQL2);                Ps.setint (1, money);                Ps.setstring (2, toname);//Transfer to Ps.executeupdate ();            Conn.commit ();//COMMIT TRANSACTION flag = true;            }else{System.out.println ("Sorry, the account you entered is incorrect and cannot be transferred");        }} catch (SQLException e) {e.printstacktrace ();            } finally {try {dbutil.closeall (conn, ps,rs);            } catch (SQLException e) {e.printstacktrace ();    }} return flag;        }//All account Query method information public static void SelectAll () {PreparedStatement PS = null;        Connection conn = null;        ResultSet rs = null;            try {conn = Dbutil.getconnection2 ();//Establish connection String sql = "SELECT * from Account";            PS = conn.preparestatement (SQL);            rs = Ps.executequery ();            System.out.println ("All account information query results are:"); System.out. println ("number \ t name \ t account balance");                while (Rs.next ()) {int id = rs.getint ("id");                String name = rs.getstring ("name");                int balance = Rs.getint ("balance");            System.out.println (id + "\ t" + name + "\ T" + balance);        }} catch (SQLException e) {e.printstacktrace ();            } finally {try {dbutil.closeall (conn, PS, RS);            } catch (SQLException e) {e.printstacktrace ();        }}}//Query single account information @SuppressWarnings ("resource") public static void Selectpart (String balname) {        PreparedStatement PS = null;        Connection conn = null;        ResultSet rs = null;            try {conn = Dbutil.getconnection2 ();//Establish connection String SQL3 = "SELECT * from account where name=?";            PS = conn.preparestatement (SQL3);            Ps.setstring (1, balname);            rs = Ps.executequery (); Boolean flag = Rs.neXT ();                if (flag = = True) {System.out.println (balname + "account information query result is:");                System.out.println ("the number \ t name \ t account balance");                rs = Ps.executequery ();                    while (Rs.next ()) {int id = rs.getint ("id");                    String name = rs.getstring ("name");                    int balance = Rs.getint ("balance");                System.out.println (id + "\ t" + name + "\ T" + balance);            }} else {System.out.println ("The account information you entered does not exist, please re-enter ...");        }} catch (SQLException e) {e.printstacktrace ();            } finally {try {dbutil.closeall (conn, PS, RS);            } catch (SQLException e) {e.printstacktrace (); }}}//Save method public static Boolean Savemoney (String savename, int Savmoney) {Boolean flag = False        ;        Connection conn = null;        PreparedStatement PS = null; String SQL6 = "Update account set balance=balance+?"        where name=? ";        int count = 0;            try {conn = Dbutil.getconnection2 ();            PS = conn.preparestatement (SQL6);            Ps.setint (1, Savmoney);            Ps.setstring (2, savename);            Count = Ps.executeupdate ();            if (count! = 0) {flag = true;        }} catch (SQLException e) {e.printstacktrace ();            } finally {try {Dbutil.closepart (conn, PS);            } catch (SQLException e) {e.printstacktrace ();    }} return flag;        }//Take Money method public static Boolean Drawmoney (String drawname, int Dramoney) {Boolean flag = false;        Connection conn = null;        PreparedStatement PS = null; String SQL7 = "Update account set balance=balance-?"        where name=? ";        int count = 0;            try {conn = Dbutil.getconnection2 (); PS = conn.preparestatement (SQL7);           Ps.setint (1, Dramoney);            Ps.setstring (2, drawname);            Count = Ps.executeupdate ();            if (count! = 0) {flag = true;        }} catch (SQLException e) {e.printstacktrace ();            } finally {try {Dbutil.closepart (conn, PS);            } catch (SQLException e) {e.printstacktrace ();    }} return flag;        }//Create a new account public static Boolean Openaccount (String opname, int opbalance) {Boolean flag = false;        Connection conn = null;        PreparedStatement PS = null;        String sql9 = "INSERT into account (Name,balance) VALUES (?,?)";        int count = 0;            try {conn = Dbutil.getconnection2 ();            PS = conn.preparestatement (SQL9);            Ps.setstring (1, opname);            Ps.setint (2, opbalance);            Count = Ps.executeupdate ();            if (count! = 0) {flag = true; }       } catch (SQLException e) {e.printstacktrace ();            } finally {try {Dbutil.closepart (conn, PS);            } catch (SQLException e) {e.printstacktrace ();    }} return flag; }//Show Balance Method @SuppressWarnings ("resource") public static void Showbalance (String showname) {Preparedstateme        NT PS = null;        Connection conn = null;        ResultSet rs = null; try {conn = Dbutil.getconnection2 ();//Establish connection String Sql10 = "Select Balance from account where name=            ?";            PS = conn.preparestatement (SQL10);            Ps.setstring (1, showname);                rs = Ps.executequery ();                rs = Ps.executequery ();                    while (Rs.next ()) {int shbalance = Rs.getint ("balance");                System.out.println (ShowName + "account Current balance is:" +shbalance);   }} catch (SQLException e) {e.printstacktrace ();     } finally {try {dbutil.closeall (conn, PS, RS);            } catch (SQLException e) {e.printstacktrace (); }        }    }}

Run Result:

Welcome to the Analog banking interface Please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 open account 8 exit): 2 Please select (1: Check all account information 2: Personal account information): 1 All account information query result is: Numbered name account Balance 1 Xiang Yu 350130202     Liu Bang 200029803 li Shimin 476180004 Zhao Kuangyin 239900005 Zhu Yuanzhang 123560006 win politics 322000007 Caocao 2000000008 Sun Quan 14500000 Please enter your choice (1 transfer 2 Enquiry 3 Deposit 4 Withdrawal 5 open account 8 exit): 1 Please enter your account name: Li Shimin Please enter the username: please input the transfer amount: 3000 transfer the current balance of the account is: 200003000 Li Shimin Account current balance is: 47615000 Please enter your choice (1 rpm) Account 2 Enquiry 3 Deposit 4 Withdrawal 5 Account opening 8 exit: 1 Please enter the name of the transfer account: hehe Please enter the account name: haha Please enter the transfer amount: 20000Sorry, you entered the wrong account, can not be transferred processing please check the information you entered is correct, please enter the correct information, re-transact this business, Thank you! Please enter your choice (1 Transfer 2 Enquiry 3 Deposit 4 Withdrawals 5 open account 8 exit): 2 Please select (1: Check all account information 2: Personal account information): 2 Please enter enquiry account name: Liu Bangliubong Account information Query result is: Number name account balance 2 Liu Bang 20002980 please Enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 open account 8 exit): 2 Please select (1: Check all account information 2: Personal account information): 3 Your options are wrong, please re-enter please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 Account 8 exit): 2 Please select (1: Check all account information 2: Personal account information): 2 Please enter the account name: haha you entered the account information does not exist, please re-enter: Please enter your choice (1 Transfer 2 Enquiry 3 Deposit 4 Withdrawals 5 open account 8 exit): 3 Please enter the deposit account name: Zhu Yuanzhang Please enter the deposit amount: 300000 deposit successful Zhu Yuanzhang account current balance is: 12656000 Please enter your choice (1 Transfer 2 Query 3 deposit 4 Take Section 5 Account opening 8 exit): 3 Please enter the deposit account name: hehe Please enter the deposit amount: 3300 The account information you entered is incorrect and the deposit failed. Please enter your choice (1 Transfer 2 Enquiry 3 Deposit 4 Withdrawals5 Account opening 8 exit): 4 Please enter the withdrawal account name: Caocao Please enter the withdrawal amount: 250 The current balance of the account is: 200002750 Please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 open account 8 exit): 4 Please enter the withdrawal account name: haha Please enter the withdrawal amount: 200 you lose The account information entered is incorrect, the withdrawal failed. Please enter your choice (1 Transfer 2 Enquiry 3 Deposit 4 Withdrawals 5 open account 8 exit): 5 Please enter the account name: Liyuan Please enter the deposit amount: 300000000 Congratulations, the account is successful. Current account information: Liyuan account information Query result is: Numbered name account balance 9 Liyuan 300  000000 Please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 open account 8 exit): 2 Please select (1: Check all account information 2: Personal account information): 1 All account information query result is: Number name account Balance 1 Xiang Yu 350130202 Liu Bang 200029803 Li Shimin 476150004 Zhao Kuangyin 239900005 Zhu Yuanzhang 126560006 win politics 322000007 Caocao 2000027508 Sun Quan 145000009 Liyuan 30000000 0 Please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 open account 8 exit): 6 Your options are wrong, please re-enter please enter your choice (1 Transfer 2 Query 3 deposit 4 Withdrawals 5 account opening 8 exit): 8 Thank you for coming, goodbye!!

Java Summary (essay)--code summary JDBC and transaction, take bank transfer, audit, etc. for example