Java Tutorial/Database/Date Time Timestamp

Содержание

1 Convert a java.sql.Timestamp Object to a java.util.Date Object?
2 Convert a String Date Such as 10 to a java.sql.Date Object?
3 Convert a Timestamp to Month-Day-Year
4 Convert into java.sql.Time into java.util.Calendar
5 Creating java.sql.Date Using GregorianCalendar
6 Creating java.sql.Date Using java.util.Calendar
7 Creating java.sql.Date Using java.util.Date
8 Creating java.sql.Date Using the java.sql.Date.valueOf() Method
9 Get a Date for a Specific Time Zone
10 Get a Date Label from a java.sql.Timestamp Object
11 Get Date value from ResultSet
12 Get the Current Date as a java.util.Date Object
13 Get the Current Timestamp as a java.sql.Time Object?
14 Get TIMESTAMP value from ResultSet
15 Get TIME value from ResultSet
16 Getting a Timestamp Object Using java.util.Date
17 Getting a Timestamp Object Using System.currentTimeMillis()
18 Insert Date value
19 Insert TIMESTAMP value
20 Insert TIME value
21 Make a java.sql.Timestamp Object for a Given Year, Month, Day, Hour
22 Returns a java.sql.Timestamp equal to the current time
23 Working with Date, Time, and Timestamp in JDBC

Convert a java.sql.Timestamp Object to a java.util.Date Object?

public static java.util.Date toDate(java.sql.Timestamp timestamp) {
    long milliseconds = timestamp.getTime() + (timestamp.getNanos() / 1000000);
    return new java.util.Date(milliseconds);
}

Convert a String Date Such as 10 to a java.sql.Date Object?

import java.text.ParseException;
import java.text.SimpleDateFormat;
public class MainClass {
  public static void main(String[] args) throws ParseException {
    try {
      SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
      String date = "2003/01/10";
      java.util.Date utilDate = formatter.parse(date);
      java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
      System.out.println("date:" + date);
      System.out.println("sqlDate:" + sqlDate);
    } catch (ParseException e) {
      System.out.println(e.toString());
      e.printStackTrace();
    }
  }
}

date:2003/01/10
sqlDate:2003-01-10

Convert a Timestamp to Month-Day-Year

import java.sql.Timestamp;
import java.text.SimpleDateFormat;
public class MainClass {
  private static final SimpleDateFormat monthDayYearformatter = new SimpleDateFormat(
      "MMMMM dd, yyyy");
  private static final SimpleDateFormat monthDayformatter = new SimpleDateFormat("MMMMM dd");
  public static String timestampToMonthDayYear(Timestamp timestamp) {
    if (timestamp == null) {
      return null;
    } else {
      return monthDayYearformatter.format((java.util.Date) timestamp);
    }
  }
  public static String timestampToMonthDay(Timestamp timestamp) {
    if (timestamp == null) {
      return null;
    } else {
      return monthDayformatter.format((java.util.Date) timestamp);
    }
  }
  public static java.sql.Timestamp getTimestamp() {
    java.util.Date today = new java.util.Date();
    return new java.sql.Timestamp(today.getTime());
  }
}

Convert into java.sql.Time into java.util.Calendar

import java.sql.Time;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
 * Provides methods helpful in making object conversions not provided for by the
 * Sun or MyFaces distributions.
 * 
 * @author 
 * 
 */
public class ConversionUtil {
  /**
   * convert into java.sql.Time (or into java.util.Calendar
   * 
   * @param date
   *          The date containing the time.
   * @param am
   *          Whether this should be am (true) or pm (false)
   * @return
   */
  public static Time convertDateToTime(Date date, boolean am) {
    if (date == null) {
      return null;
    }
    Calendar cal = new GregorianCalendar();
    cal.setTime(date);
    int hourOfDay = cal.get(Calendar.HOUR_OF_DAY);
    if (am) {
      // Check to make sure that the hours are indeed am hours
      if (hourOfDay > 11) {
        cal.set(Calendar.HOUR_OF_DAY, hourOfDay - 12);
        date.setTime(cal.getTimeInMillis());
      }
    } else {
      // Check to make sure that the hours are indeed pm hours
      if (cal.get(Calendar.HOUR_OF_DAY) < 11) {
        cal.set(Calendar.HOUR_OF_DAY, hourOfDay + 12);
        date.setTime(cal.getTimeInMillis());
      }
    }
    return new Time(date.getTime());
  }
}

Creating java.sql.Date Using GregorianCalendar

import java.util.Calendar;
import java.util.GregorianCalendar;
public class MainClass {
  public static void main(String[] args) {
    Calendar calendar = new GregorianCalendar(2000, // year
        10, // month
        1); // day of month
    java.sql.Date date = new java.sql.Date(calendar.getTimeInMillis());
  }
}

Creating java.sql.Date Using java.util.Calendar

import java.util.Calendar;
public class MainClass {
  public static void main(String[] args) {
    // get a calendar using the default time zone and locale.
    Calendar calendar = Calendar.getInstance();
    // set Date portion to January 1, 1970
    calendar.set(Calendar.YEAR, 1970);
    calendar.set(Calendar.MONTH, Calendar.JANUARY);
    calendar.set(Calendar.DATE, 1);
    // normalize the object
    calendar.set(Calendar.HOUR_OF_DAY, 0);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.SECOND, 0);
    calendar.set(Calendar.MILLISECOND, 0);
    java.sql.Date javaSqlDate = new java.sql.Date(calendar.getTime().getTime());
  }
}

Creating java.sql.Date Using java.util.Date

public class MainClass {
  public static void main(String[] args) {
    java.util.Date today = new java.util.Date();
    System.out.println(new java.sql.Date(today.getTime()));
  }
}

Creating java.sql.Date Using the java.sql.Date.valueOf() Method

The java.sql.Date object"s valueOf() method accepts a String, which must be the date in JDBC time escape format: YYYY-MM-DD.

public class MainClass {
  public static void main(String[] args) {
    String date = "2000-11-01";
    java.sql.Date javaSqlDate = java.sql.Date.valueOf(date);
  }
}

Get a Date for a Specific Time Zone

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Calendar;
import java.util.TimeZone;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn.createStatement();
    st.executeUpdate("create table survey (id int,myDate DATE );");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Date sqlDate = new java.sql.Date(new java.util.Date().getTime());
    pstmt.setDate(2, sqlDate);
    pstmt.executeUpdate();
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    Calendar cal = Calendar.getInstance();
    // get the TimeZone for "America/Los_Angeles"
    TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
    cal.setTimeZone(tz);
    while (rs.next()) {
      // the JDBC driver will use the time zone information in
      // Calendar to calculate the date, with the result that
      // the variable dateCreated contains a java.sql.Date object
      // that is accurate for "America/Los_Angeles".
      java.sql.Date dateCreated = rs.getDate(2, cal);
      System.out.println(dateCreated);
    }
    rs.close();
    st.close();
    conn.close();
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

Get a Date Label from a java.sql.Timestamp Object

import java.sql.Timestamp;
public class MainClass {
  private static final long One_Day_In_Milliseconds = 86400000;
  public static final String DATE_LABEL_TODAY = "Today";
  public static final String DATE_LABEL_YESTERDAY = "Yesterday";
  public static final String DATE_LABEL_THIS_MONTH = "This Month";
  public static final String DATE_LABEL_OLDER = "Older";
  public static final String DATE_LABEL_NONE = "";
  public static java.sql.Timestamp getTimestamp() {
    java.util.Date today = new java.util.Date();
    return new java.sql.Timestamp(today.getTime());
  }
  public static String getDateLabel(java.sql.Timestamp ts, java.sql.Timestamp now) {
    long tsTime = ts.getTime();
    long nowTime = now.getTime();
    long quotient = (nowTime - tsTime) / One_Day_In_Milliseconds;
    if (quotient < 1) {
      return DATE_LABEL_TODAY;
    } else if (quotient < 2) {
      return DATE_LABEL_YESTERDAY;
    } else if (quotient < 30) {
      return DATE_LABEL_THIS_MONTH;
    } else {
      return DATE_LABEL_OLDER;
    }
  }
  public static void main(String[] args) {
    java.sql.Timestamp now = getTimestamp();
    java.sql.Timestamp ts1 = getTimestamp();
    System.out.println(getDateLabel(ts1, now));
    System.out.println(ts1.toString());
    System.out.println("-------------");
    // timestamp in format yyyy-mm-dd hh:mm:ss.fffffffff
    java.sql.Timestamp ts22 = java.sql.Timestamp.valueOf("2007-01-06 09:01:10");
    System.out.println(getDateLabel(ts22, now));
    System.out.println(ts22.toString());
    System.out.println("-------------");
    java.sql.Timestamp ts2 = java.sql.Timestamp.valueOf("2007-02-02 10:10:10");
    System.out.println(getDateLabel(ts2, now));
    System.out.println(ts2.toString());
    System.out.println("-------------");
    java.sql.Timestamp ts3 = java.sql.Timestamp.valueOf("2004-07-18 10:10:10");
    System.out.println(getDateLabel(ts3, now));
    System.out.println(ts3.toString());
    System.out.println("-------------");
    java.sql.Timestamp ts4 = java.sql.Timestamp.valueOf("2007-02-01 10:10:10");
    System.out.println(getDateLabel(ts4, now));
    System.out.println(ts4.toString());
    System.out.println("-------------");
  }
}

Today
2007-02-02 13:23:02.933
-------------
This Month
2007-01-06 09:01:10.0
-------------
Today
2007-02-02 10:10:10.0
-------------
Older
2004-07-18 10:10:10.0
-------------
Yesterday
2007-02-01 10:10:10.0
-------------

Get Date value from ResultSet

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate DATE );");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Date  sqlDate = new java.sql.Date(new java.util.Date().getTime());
    pstmt.setDate(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    while (rs.next()) {
        System.out.print(rs.getDate(2));
    }
    rs.close();
    st.close();
    conn.close();
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

2007-02-02

Get the Current Date as a java.util.Date Object

The class java.util.Date represents a specific instant in time, with millisecond precision.

public class MainClass {
  public static void main(String[] args) {
    java.util.Date date = new java.util.Date();
  }
}

Get the Current Timestamp as a java.sql.Time Object?

public class MainClass {
  public static void main(String[] args) {
    java.util.Date today = new java.util.Date();
    System.out.println(new java.sql.Time(today.getTime())); 
  }
}

Get TIMESTAMP value from ResultSet

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate TIMESTAMP );");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Timestamp  sqlDate = new java.sql.Timestamp(new java.util.Date().getTime());
    pstmt.setTimestamp(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    while (rs.next()) {
        System.out.print(rs.getTimestamp(2));
    }
    rs.close();
    st.close();
    conn.close();
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

2007-02-02 12:46:40.632

Get TIME value from ResultSet

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate TIME );");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Time  sqlDate = new java.sql.Time(new java.util.Date().getTime());
    pstmt.setTime(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    while (rs.next()) {
        System.out.print(rs.getTime(2));
    }
    rs.close();
    st.close();
    conn.close();
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

12:47:21

Getting a Timestamp Object Using java.util.Date

public class MainClass {
  public static void main(String[] args) {
    java.util.Date today = new java.util.Date();
    System.out.println(new java.sql.Timestamp(today.getTime()));
  }
}

Getting a Timestamp Object Using System.currentTimeMillis()

public class MainClass {
  public static void main(String[] args) {
    new java.sql.Timestamp(System.currentTimeMillis());
  }
}

Insert Date value

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate DATE);");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Date sqlDate = new java.sql.Date(new java.util.Date().getTime());
    pstmt.setDate(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    outputResultSet(rs);
    rs.close();
    st.close();
    conn.close();
  }
  private static void outputResultSet(ResultSet rs) throws Exception {
    ResultSetMetaData rsMetaData = rs.getMetaData();
    int numberOfColumns = rsMetaData.getColumnCount();
    for (int i = 1; i < numberOfColumns + 1; i++) {
      String columnName = rsMetaData.getColumnName(i);
      System.out.print(columnName + "   ");
    }
    System.out.println();
    System.out.println("----------------------");
    while (rs.next()) {
      for (int i = 1; i < numberOfColumns + 1; i++) {
        System.out.print(rs.getString(i) + "   ");
      }
      System.out.println();
    }
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

ID   MYDATE   
----------------------
1   2007-02-02

Insert TIMESTAMP value

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate TIMESTAMP );");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Timestamp  sqlDate = new java.sql.Timestamp(new java.util.Date().getTime());
    pstmt.setTimestamp(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    outputResultSet(rs);
    rs.close();
    st.close();
    conn.close();
  }
  private static void outputResultSet(ResultSet rs) throws Exception {
    ResultSetMetaData rsMetaData = rs.getMetaData();
    int numberOfColumns = rsMetaData.getColumnCount();
    for (int i = 1; i < numberOfColumns + 1; i++) {
      String columnName = rsMetaData.getColumnName(i);
      System.out.print(columnName + "   ");
    }
    System.out.println();
    System.out.println("----------------------");
    while (rs.next()) {
      for (int i = 1; i < numberOfColumns + 1; i++) {
        System.out.print(rs.getString(i) + "   ");
      }
      System.out.println();
    }
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

ID   MYDATE   
----------------------
1   2007-02-02 12:45:19.914000000

Insert TIME value

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn
        .createStatement();
    st.executeUpdate("create table survey (id int,myDate TIME);");
    String INSERT_RECORD = "insert into survey(id, myDate) values(?, ?)";
    
    PreparedStatement pstmt = conn.prepareStatement(INSERT_RECORD);
    pstmt.setString(1, "1");
    java.sql.Time sqlDate = new java.sql.Time(new java.util.Date().getTime());
    pstmt.setTime(2, sqlDate);
    
    pstmt.executeUpdate();
    
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    outputResultSet(rs);
    rs.close();
    st.close();
    conn.close();
  }
  private static void outputResultSet(ResultSet rs) throws Exception {
    ResultSetMetaData rsMetaData = rs.getMetaData();
    int numberOfColumns = rsMetaData.getColumnCount();
    for (int i = 1; i < numberOfColumns + 1; i++) {
      String columnName = rsMetaData.getColumnName(i);
      System.out.print(columnName + "   ");
    }
    System.out.println();
    System.out.println("----------------------");
    while (rs.next()) {
      for (int i = 1; i < numberOfColumns + 1; i++) {
        System.out.print(rs.getString(i) + "   ");
      }
      System.out.println();
    }
  }
  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
}

ID   MYDATE   
----------------------
1   12:44:14

Make a java.sql.Timestamp Object for a Given Year, Month, Day, Hour

import java.sql.Timestamp;
import java.util.Calendar;
import java.util.GregorianCalendar;
public class MainClass {
  public static void main(String[] a) {
    System.out.println(makeTimestamp(2002,02,02,02,02,02,02));
  }
  public static Timestamp makeTimestamp(int year, int month, int day, int hour, int minute,
      int second, int millisecond) {
    Calendar cal = new GregorianCalendar();
    cal.set(Calendar.YEAR, year);
    cal.set(Calendar.MONTH, month - 1);
    cal.set(Calendar.DATE, day);
    cal.set(Calendar.HOUR_OF_DAY, hour);
    cal.set(Calendar.MINUTE, minute);
    cal.set(Calendar.SECOND, second);
    cal.set(Calendar.MILLISECOND, millisecond);
    // now convert GregorianCalendar object to Timestamp object
    return new Timestamp(cal.getTimeInMillis());
  }
}

2002-02-02 02:02:02.002

Returns a java.sql.Timestamp equal to the current time

public class Utils {
  
  /**
   * Returns a java.sql.Timestamp equal to the current time
   **/
  public static java.sql.Timestamp now() {
      return new java.sql.Timestamp(new java.util.Date().getTime());
  }
}

Working with Date, Time, and Timestamp in JDBC

The java.sql package provides the following classes that deal with date-related data types:

java.sql.Date: Mapping for SQL DATE.
java.sql.Time: Mapping for SQL TIME.
java.sql.Timestamp: Mapping for SQL TIMESTAMP.