1.Java a. Database connection 1.Drivermanager link database String className, url, uid, pwd; className = \ ‘Oracle.jdbc.driver.OracleDriver \’; uid = \ ‘scott \’; pwd = \ ‘ tiger \’;…
1.Java
a. 1.Drivermanager link database database connection

String className, url, uid, pwd;

className = \ “Oracle.jdbc.driver.OracleDriver \”;

uid = \ “scott \”;

pwd = \ “tiger \”;

url = \ “jdbc: oracle: thin: @ localhost: 1521: ora92 \”;

Class.forName (classname);

Connection conn = DriverManager.getConnection (url, uid, pwd);

2.JNDI Links Database

String jndi = \ “jdbc / db \”; / / e20-040 9L0-609 data source name

/ / Context is a set of binding names to objects composed of

Hashtable env = new Hashtable ();

Context ctx = (Context) new InitialContext.lookup (\ “env \ “);// context where access to the data source object point

DataSource ds = (DataSource) ctx.lookup (jndi); / / find the data source

Connection conn = ds.getConnection ();//

b. implementation of the sql statement

String sql;

StateMent stat = conn.createStatement ();

ResultSet rs = stat.executeQuery (sql); / / implementation of the data query (select);

stat.executeUpdate (sql); / / implementation of data update statements (inset into, delete, update, drop)

stat.close ();

c. to execute sql statements with preparedStatement

String sql = \ “inset into table (id, name) values (?,?) \”;

PreparedStatement ps = conn.prepareStatement (sql);

ps.setInt (1,001);

ps.setString (2, \ “zhangmanli \”);

ps.executeQuery ();

int count = ps.executeUpdate ();

d. address the implementation of the results

Query, ResultSet object to return recordset

Update statement, return number, said the impact of the number of records updated

javax.sql .*

javax.naming .*;

Data processing:

A close connection to automatically submit

conn.setAutoCommit (false);

2 implementation of a series of sql statements

Statement sm;

sm = conn.createStatement (sql);

sm.executeUpdate ();

sm.close ();

3. Submit:

conn.commit ();

4. Rollback mechanism;

conn.rollback ();

e: Threading:

D: jndi and dataSource to get the database link:

import java.sql.ResultSet;

import java.sql .*;

import javax.sql.DataSource;

import javax.naming.Context;

import javax.naming.InitialContext;

import java.util.Hashtable;

import java.util.Properties;

import java.io. *;

public class BasicExample (

public static void main (String args []) (

Connection conn = null;

try (

Properties prop = new Properties ();

prop.load (new FileInputStream (\ “simple.properties \”));

Hashtable env = new Hashtable ();

env.put (Context.INITIAL_CONTEXT_FACTORY, prop.getProperty (\ “INITIAL_CONTEXT_FACTORY \”));

env.put (Context.PROVIDER_URL, prop.getProperty (\ “PROVIDER_URL \”));

InitialContext ctx = new InitialContext (env);

DataSource ds = (DataSource) ctx.lookup (\ “Book \”);

Conn = ds.getConnection ();

Statement stat = conn.createStatement ();;

ResultSet rs = stmt.executeQuery (sql);

while (rs.next ()) (

int id = Integer.parseInt (rs.getString (\ “userId \”));

String userName = rs.getString (\ “username \”);

)

) Catch (SQLException e) (

e.printStackTrace ();

) Finally (

try (

if (conn! = null) (

conn.close ();

)

) Catch (SQLException e) (

e.printStackTrace ();

)

)

)

);

public class DateUtils (/ ** * get the current time and date string * / public static String getCurrentDateStr (DateFormatType dateFormatType) (Date date = getCurrentDat …
public class DateUtils (
/ **

* Get the current time and date string

* /

public static String getCurrentDateStr (DateFormatType dateFormatType) (

Date date = getCurrentDate ();

return (String) OpearationDate (date, dateFormatType.getValue ());

)

/ **

* Time, date format string

* /

public static String formatDate (Date date, DateFormatType dateFormatType) (

return (String) OpearationDate (date, dateFormatType.getValue ());

)

/ **

* From the string parsing into the time, date

* /

public static Date parseDate (String dateStr, DateFormatType dateFormatType) (

return (Date) OpearationDate (dateStr, dateFormatType.getValue ());

)

/ **

* Get the current system time (original format)

* /

public static Date getCurrentDate () (

Date date = new Date (System.currentTimeMillis ());

return date;

)

/ **

* Get the current date of the year, month, day, hour, minute, second

* /

public static int getCurrentTime (TimeFormatType timeFormatType) (

return getTime (getCurrentDate (), timeFormatType);

)

/ **

* Get the specified date of the year, month, day, hour, minute, second

* /

public static int getTime (Date date, TimeFormatType timeFormatType) (

try (

Calendar c = Calendar.getInstance ();

c.setTime (date);

int type = timeFormatType.getValue ();

int i = c.get (type);

return type == 2? i + 1: i;

) Catch (Exception e) (

throw new RuntimeException (“get failed”, e);

)

)

/ **

* Get the number of milliseconds specified date

* /

public static long getMillis (Date date) (

java.util.Calendar c = java.util.Calendar.getInstance ();

c.setTime (date);

return c.getTimeInMillis ();

)

/ **

* Date added together, by operation

*

* Results are returned units: days

* /

public static int operationDate (Date date, Date diffDate, DateOperationType dateOperationType) (

long add = getMillis (date) + getMillis (diffDate);

long diff = getMillis (date) – getMillis (diffDate);

return (int) ((dateOperationType.getValue ()? add: diff) / (24 * 3600 * 1000));

)

/ **

* Add date month, reducing operation

* /

public static Date operationDateOfMonth (Date date, int month, DateOperationType dateOperationType) (

Calendar c = Calendar.getInstance ();

c.setTime (date);

c.add (Calendar.MONTH, dateOperationType.getValue ()? month: month – (month * 2));

return c.getTime ();

)

/ **

* Date of days add up, by operation

* /

public static Date operationDateOfDay (Date date, int day, DateOperationType dateOperationType) (

Calendar c = Calendar.getInstance ();

c.setTime (date);

long millis = c.getTimeInMillis ();

long millisOfday = day * 24 * 3600 * 1000;

long sumMillis = dateOperationType.getValue ()? (millis + millisOfday): (millis – millisOfday);

c.setTimeInMillis (sumMillis);

return c.getTime ();
)

private static Object OpearationDate (Object object, String formatStr) (

if (object == null | | null == formatStr | | “”. equals (formatStr)) (

throw new RuntimeException (“argument can not be empty”);

)

SimpleDateFormat format = new SimpleDateFormat (formatStr);

try (

if (object instanceof Date)

return format.format (object);

else

return format.parse (object.toString ());

) Catch (Exception e) (

throw new RuntimeException (“operation failed”, e);

)

)

public enum DateOperationType (

/ **

* Add operation

* /

ADD (true),

/ **

* Reduction operation

* /

DIFF (false);

private final boolean value;

DateOperationType (boolean operation) (

this.value = operation;

)

public boolean getValue () (

return value;

)

)

public enum TimeFormatType (

YEAR (1), MONTH (2), DAY (5), HOUR (11), MINUTE (12), SECOND (13);

private final int value;

TimeFormatType (int formatStr) (

this.value = formatStr;

)

public int getValue () (

return value;

)

)

public enum DateFormatType (

/ **

* Format: yyyy-MM-dd HH: mm: ss

* /

DATE_FORMAT_STR (“yyyy-MM-dd HH: mm: ss”),

/ **

* Format: yyyyMMddHHmmss

* /

SIMPLE_DATE_TIME_FORMAT_STR (“yyyyMMddHHmmss”),

/ **

* Format: yyyy-MM-dd

* /

SIMPLE_DATE_FORMAT_STR (“yyyy-MM-dd”),

/ **

* Format: yyyy / MM / dd

* /

SIMPLE_DATE_FORMAT_VIRGULE_STR (“yyyy / MM / dd”),

/ **

* Format: HH: mm: ss

* /

HOUR_MINUTE_SECOND (“HH: mm: ss”),

/ **

* Format: HH: mm

* /

HOUR_MINUTE (“HH: mm”);

private final String value;

DateFormatType (String formatStr) (

this.value = formatStr;

)

public String getValue () (

return value;

)

)

)