Java JDBC Connection Database

I. Native JDBC Connection steps:

//1. Registering the database driver//com. MySQL.jdbc.DriverClass.forName ("database-driven full class name");//2. Get a database connectionConnection conn = Drivermanager.getconnection ("Connection URL","User name","Password" );//3. Create a sessionPreparedStatement PS =NULL;/4Execute SQL statements, add, delete, modify Records ps.executeupdate ("Add, delete, modify a recorded SQL statement"); //or query StatementsResultSet rs = ps.executequery ("SQL statement for querying Records"); //5. Working with query result sets while(Rs.next ()) {//operations on Records}    //6. Close the connectionRs.close ();  Ps.close (); Conn.close ();

2. using C3P0

Resource file

Driverclass = com.mysql.jdbc.Driver      = jdbc:mysql://localhost:3306/test     Username = root      123456

Establish a connection

Combopooleddatasource CPDs =NewCombopooleddatasource (); //Load Database driverTry{Cpds.setdriverclass ("Com.ibm.db2.jcc.DB2Driver"); } Catch(propertyvetoexception E1) {e1.printstacktrace (); }        //set the address, user name, and password to access the databaseCpds.setjdbcurl ("jdbc:db2://10.10.38.138:50000/malltest"); Cpds.setuser ("Db2inst1"); Cpds.setpassword ("Db2inst1"); //set some configuration of C3P0, use default if not setCpds.setminpoolsize (5); Cpds.setacquireincrement (5); Cpds.setmaxpoolsize ( -); Cpds.setmaxstatements ( the); Connection Conn=NULL; Statement stmt=NULL; ResultSet RS=NULL; Try {        //Create a database connectionconn =cpds.getconnection (); //Get database Operations Objectstmt =conn.createstatement (); //manipulating databases to get result setsrs = Stmt.executequery ("SELECT * from Ly.t_merinf where merid= ' M0000178 '"); //working with result sets     while(Rs.next ()) {System. out. println (Rs.getstring ("Mername")); }    } Catch(SQLException e) {e.printstacktrace (); } finally {        //Close Result set    if(rs! =NULL) {            Try{Rs.close ();}Catch(SQLException e) {}}//Close Database Operations Object    if(stmt! =NULL) {            Try{Stmt.close ();}Catch(SQLException e) {}}//To close a database connection    if(Conn! =NULL) {            Try{Conn.close ();}Catch(SQLException e) {}}Try{Datasources.destroy (CPDs); } Catch(SQLException e) {e.printstacktrace (); }    }

3. using DBCP

Configuration file

driverclassname=com.ibm.db2.jcc.DB2Driver    url=jdbc:db2://10.10.38.138:50000/malltest     username=db2inst1    Password=db2inst1    initialsize=3     Maxactive=5    maxidle=3    minidle=1     maxwait=30000

Connecting to a database

//1. Create a connection poolDataSource ds =NULL; Try{Properties prop=NewProperties (); //to load a property file through a classpathProp.load (dbcptest.class. getClassLoader (). getResourceAsStream ("database/dbcp/dbcp.properties")); //Get Data sourceDS =Basicdatasourcefactory.createdatasource (prop); } Catch(IOException e) {e.printstacktrace (); } Catch(Exception e) {e.printstacktrace (); } Connection Conn=NULL; Statement stmt=NULL; ResultSet RS=NULL; Try {        //2. Get a database connectionconn =ds.getconnection (); //3. Create a Database Action objectstmt =conn.createstatement (); //4. Manipulating the database to get the result setrs = Stmt.executequery ("SELECT * from Ly.t_merinf where merid= ' M0000178 '"); //5. Working with result sets     while(Rs.next ()) {System. out. println (Rs.getstring ("Mername")); }    } Catch(SQLException e) {e.printstacktrace (); } finally {        //Close Result set    if(rs! =NULL) {            Try{Rs.close ();}Catch(SQLException e) {}}//Close Database Operations Object    if(stmt! =NULL) {            Try{Stmt.close ();}Catch(SQLException e) {}}//To close a database connection    if(Conn! =NULL) {            Try{Conn.close ();}Catch(SQLException e) {} }}

Java JDBC Connection Database