JDBC: Writing JDBC programs with object-oriented thinking

Topic Description:The student information is added to the data table, and the student's information can be queried through the ID number of the ticket. Name Type Nullable Default Comments
----------- ------------ -------- ------- --------
Idcard Number (Ten) Y
Examcard Number (Ten) Y
Studentname VARCHAR2 (Y)
Lacation VARCHAR2 (Y)
GRADE Number (3) Y

Test Class

Package Xuezaipiao3;import Java.sql.connection;import Java.sql.resultset;import java.sql.statement;import Java.util.scanner;import Xuezaipiao1. jdbc_tools;/** * Think: * Add a student information record to the datasheet, then the student information can create a student class to store the information * Step: * 1) Student member variable corresponding STUDNT data table * 2) Create a method Addstudent (Stu Dent Student) * 3) Execute the corresponding SQL operation in method * @author Kevy * */public class Thinkinjdbc {public static void main (string[] args) {S Tudent s = getstudentfromconsole (); Addstudent (s); Querystudent ();} public static void Querystudent () {int searchtype = Getsearchtypefromconsole (); Student Student = searchstudent (searchtype);p rintstudent (Student);} /** * Print Student information * @param student */private static void Printstudent (student student) {if (student!=null) {System.out.println (s tudent);} Else{system.out.println ("Check no this person!");}} /** * * @param searchtype 1 and 2 * @return */private static Student searchstudent (int searchtype) {String sql = "Select * FROM student "+" where "; Scanner Scanner = new Scanner (system.in), if (searchtype==1) {System.out.print ("Please enter identity card:"); inT id = scanner.nextint (); sql = sql + "Idcard =" +id;} Else{system.out.print ("Please enter admission ticket:"); int id = scanner.nextint (); sql = sql + "Examcard =" +id;} Student Student = getstudent (sql); Scanner.close (); return Student;} /** * Returns Student object based on incoming SQL * @param SQL * @return */private static Student getstudent (String sql) {Connection Connection = Null Statement Statement = null; ResultSet rs = null; Student stu = null;try {connection = jdbc_tools.getconnection (); statement = Connection.createstatement (); rs = Statement.executequery (SQL), if (Rs.next ()) {stu = new Student (Rs.getint ("Idcard"), Rs.getint ("Examcard"), Rs.getstring ("Studentname"), Rs.getstring ("Lacation"), Rs.getint ("GRADE"));}} catch (Exception e) {e.printstacktrace ();} Finally{jdbc_tools.relasesource (RS, connection, statement);} return Stu;} /** * * @return 1 with ID card query, 2 with the ticket number to query other invalid */@SuppressWarnings ("resource") private static int getsearchtypefromconsole () { System.out.println ("Please enter query type: 1. ID Card Enquiry 2. Admission Ticket Enquiry"); System.out.print ("Your choice:"); Scanner Scanner = New Scanner (system.in), int type = Scanner.nextint (), if (type!=1 && type!=2) {System.out.println ("input wrong, please reenter"); throw new RuntimeException ();} Scanner.close (); return 0;} /** * Get information from the console and create student objects * @return */private static Student getstudentfromconsole () {Scanner Scanner = new Scanner (system.in ); Student Student = new Student (); System.out.print ("Idcard:"); Student.setidcard (Scanner.nextint ()); System.out.print ("Examid:"); Student.setexamid (Scanner.nextint ()); System.out.print ("Studentname:"); Student.setstudentname (Scanner.next ()); System.out.print ("llocation:"); Student.setlacation (Scanner.next ()); System.out.print ("Grade:"); Student.setgrade (Scanner.nextint ()); Scanner.close (); return student;} /** * Add student information * @param student */public static void Addstudent (student student) {String sql = "INSERT into student" + "VALUE S ("+student.getidcard () +", "+student.getexamid () +", ' "+student.getstudentname () +" ', ' "+student.getlacation () +" ', " +student.getgrade () + ")"; Jdbc_tools.update (SQL);}}

Student class

public class Student {private int idcard;private int examid;private string studentname;private string lacation;private int Grade;public Student (int idcard, int examid, string studentname, String Lacation,int Grade) {super (); idcard = Idcard; Examid = Examid; Studentname = Studentname; Lacation = lacation; Grade = Grade;} @Overridepublic String toString () {return "Student [idcard=" + Idcard + ", examid=" + examid+ ", studentname=" + Studentna Me + ", lacation=" + lacation+ ", grade=" + Grade + "]";} Public Student () {super ();} public int Getidcard () {return idcard;} public void Setidcard (int idcard) {idcard = Idcard;} public int Getexamid () {return examid;} public void Setexamid (int examid) {examid = Examid;} Public String Getstudentname () {return studentname;} public void Setstudentname (String studentname) {studentname = Studentname;} Public String getlacation () {return lacation;} public void Setlacation (String lacation) {lacation = lacation;} Public double Getgrade () {return Grade;} public void SetgradE (int grade) {grade = Grade;}} 

JDBC Tool class

Package xuezaipiao1;/** * JDBC Tool class * Encapsulates some simple JDBC operation method * Version 1 */import java.io.fileinputstream;import java.io.FileNotFo Undexception;import Java.io.ioexception;import Java.sql.connection;import Java.sql.drivermanager;import Java.sql.resultset;import Java.sql.sqlexception;import Java.sql.statement;import Java.util.Properties;public class  Jdbc_tools {/** * method used to execute SQL, including INSRT, UPDATE, DELETE, does not contain a select * parameter String SQL statement * @return Int executed several records */public static int update (String sql) {Connection conn = null; Statement Statement = Null;int num = 0;try {try {conn = Jdbc_tools.getconnection ();} catch (Exception e) {E.printstacktrac E ();} statement = conn.createstatement (); num = statement.executeupdate (sql);} catch (SQLException e) {e.printstacktrace ();} FINALLY{JDBC_TOOLS.RELASESOURCE (conn, statement);} return num;} /** * The Select method used to execute SQL */public static void query (String SQL) {Connection conn = null; Statement Statement = null; ResultSet rs = null;try {conn = jdbc_tools.getconnection (); statement = Conn.createstatement (); rs = statement.executequery (sql); while (Rs.next ()) {System.out.println (Rs.getint ("id")); System.out.println (rs.getstring (2)); System.out.println (rs.getstring ("email"));}} catch (Exception e) {e.printstacktrace ();} Finally{jdbc_tools.relasesource (RS, conn, statement);}} /** * Used to release resources, parameters are Connection, Statement * @param conn * @param Statement */public static void Relasesource (ResultSet Rs,co Nnection Conn, Statement Statement) {if (rs! = null) {try {rs.close ()} catch (SQLException e) {//TODO auto-generated catch Blocke.printstacktrace ();}} JDBC_TOOLS.RELASESOURCE (conn, statement);} public static void Relasesource (Connection conn, Statement Statement) {if (statement!=null) {try {statement.close ();} catch (SQLException e) {e.printstacktrace ();}} Use two if, so that if an exception occurs in the middle, the program continues execution if (conn!=null) {try {conn.close ();} catch (SQLException e) {e.printstacktrace ()}}} /** * * @return * @throws Exception */public static Connection getconnection () throws Exception {Properties Properties = NeW Properties (); try {//inputstream in = GetClass (). getClassLoader (). getResourceAsStream ("jdbc.properties");// Properties.load (in);p roperties.load (New FileInputStream ("d://learnjava//learnjdbc//lesson2_ Usestatementandresultset//src//jdbc.properties "));} catch (FileNotFoundException e) {e.printstacktrace ();} catch (IOException e) {e.printstacktrace ();} String user = Properties.getproperty ("user"); String Password = properties.getproperty ("password"); String Jdbcurl = Properties.getproperty ("Jdbcurl"); String dirvername = properties.getproperty ("driver"); try {class.forname (dirvername);} catch (ClassNotFoundException E1) {e1.printstacktrace ();} Connection Connection = null;try {Connection = drivermanager.getconnection (jdbcurl, user, password);} catch ( SQLException e) {e.printstacktrace ();} return connection;}}

JDBC: Writing JDBC programs with object-oriented thinking