MySQL database connection operation user object

1. Create a user. Java

Package com. jzm. JavaBean;

Import java. Io. serializable;
Public class user implements serializable {
Private string name;
Private string password;
Private string sex;
Private string email;
Private string power;

Public String getname (){
Return name;
}
Public void setname (string name ){
This. Name = Name;
}
Public String GetPassword (){
Return password;
}
Public void setpassword (string password ){
This. Password = password;
}
Public String getsex (){
Return sex;
}
Public void setsex (string sex ){
This. Sex = sex;
}
Public String getemail (){
Return email;
}
Public void setemail (string email ){
This. Email = Email;
}
Public String getpower (){
Return power;
}
Public void setpower (string power ){
This. Power = power;
}
}

 

2. Create another conn_db.java

Package com. jzm. JavaBean;
Import java. Io. printwriter;
Import java. SQL .*;
Public class conndb {
Private Static string drivername = "com. MySQL. JDBC. Driver ";
Private Static string username = "root ";
Private Static string usrpassword = "6056067 ";
Private Static string url = "JDBC: mysql: // localhost/" + "video" +
"? User = "+ username +" & Password = "+ usrpassword +
"& Useunicode = true & characterencoding = gb2312 ";
Private Static connection conn = NULL;
Private Static statement Sm = NULL;
Private Static printwriter out = NULL;

Public static connection getconn (){
Try {
Class. forname (drivername). newinstance ();
Conn = drivermanager. getconnection (URL );
Sm = conn. createstatement ();
} Catch (exception e ){
E. printstacktrace ();
Out. Print ("database connection failed ");
}
Return conn;
}
Public void closedb ()
{
Try {
If (SM! = NULL)
{
SM. Close ();
}
Conn. Close ();
} Catch (exception e ){
E. printstacktrace ();
Out. Print ("database shutdown failed ");
}
}
 
}

3. Create a user class db_user.java

Package com. jzm. JavaBean;

Import java. SQL. connection;
Import java. SQL. resultset;
Import java. SQL. statement;
Import java. util. vector;
Public class db_user {
Private user;
Private conndb;

Public db_user (conndb) // The constructor can connect to the database.
{
This. conndb = conndb;
}

Public user getuser (string username)
{
String SQL = NULL;
Resultset rset = NULL;
Connection conn = NULL;
Try {
Conn = conndb. getconn ();
Statement Sm = conn. createstatement ();
SQL = "select * From tb_user where name = '" +
Username + "'";
SQL = new string (SQL. getbytes ("ISO8859-1"), "gb2312 ");
Rset = sm.exe cutequery (SQL );
If (rset. Next ())
{
User = new user ();
User. setname (rset. getstring ("name "));
User. setpassword (rset. getstring ("password "));
User. setsex (rset. getstring ("sex "));
User. setemail (rset. getstring ("email "));
User. setpower (rset. getstring ("power "));
Return user;
}
Return user;
} Catch (exception e ){
E. printstacktrace ();
Return NULL;
} Finally {
Conndb. closedb ();
}
}

Public Boolean adduser (User user) // Add a user
{
String SQL = NULL;
Try {
Connection conn = conndb. getconn ();
Statement Sm = conn. createstatement ();
SQL = "insert into tb_user values ('" + User. getname ()
+ "','" + User. GetPassword () + "','" + User. getsex () + "','"
+ User. getemail () + "','" + User. getpower () + "')";
SQL = new string (SQL. getbytes ("ISO8859-1"), "gb2312 ");
Sm.exe cuteupdate (SQL );
} Catch (exception e ){
E. printstacktrace ();
Return false;
} Finally {
Conndb. closedb ();
}
Return true;
}


Public Boolean deleteuser (string username) // delete a user
{
String SQL = NULL;
Connection conn = NULL;
Try {
Conn = conndb. getconn ();
Statement Sm = conn. createstatement ();
SQL = "delete from tb_user where name = '" +
Username + "'";
Int I = sm.exe cuteupdate (SQL );
If (I> = 0 ){
System. Out. println ("User deleted successfully ");
Return true;
} Else return false;
} Catch (exception e ){
E. printstacktrace ();
Return false;
} Finally {
Conndb. closedb ();
}
}

 
Public Boolean updateuser (User user) // modify user information
{
Boolean flag = false;
String SQL = NULL;
Connection conn = NULL;
Try {
Conn = conndb. getconn ();
Statement Sm = conn. createstatement ();
SQL = "Update tb_user SET Password = '"
+ User. GetPassword () + "', sex = '"
+ User. getsex () + "', email = '"
+ User. getemail () + "', power = '"
+ User. getpower () + "'where name = '"
+ User. getname () + "'";
SQL = new string (SQL. getbytes ("ISO8859-1"), "gb2312 ");
Int I = sm.exe cuteupdate (SQL );
System. Out. println ("I =" + I );
If (I> = 0 ){
Return true;
}
} Catch (exception e ){
E. printstacktrace ();
Return false;
} Finally {
Conndb. closedb ();
}
Return flag;
}

Public vector <user> getallusers () // get all user information
{
Resultset rset = NULL;
Connection conn = NULL;
Vector <user> vector = NULL;
Try {
Conn = conndb. getconn ();
Statement Sm = conn. createstatement ();
Rset = sm.exe cutequery ("select * From tb_user ");
Vector = new vector <user> ();
While (rset. Next ()){
User user = new user ();
String name = rset. getstring (1 );
String Password = rset. getstring (2 );
String sex = rset. getstring (3 );
String email = rset. getstring (4 );
String power = rset. getstring (5 );
User. setname (name );
User. setpassword (password );
User. setemail (email );
User. setsex (sex );
User. setpower (power );
Vector. Add (User );
}
Return vector;
} Catch (exception e ){
E. printstacktrace ();
System. Out. println ("failed to query all users! ");
} Finally {
Conndb. closedb ();
}
Return vector;
}
}