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C# How to add pagination in DataGridView

 
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Posted by on October 23, 2017 in C#.Net

 

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REST clients for Java, MySQL and JSON Restful Web Services

This is the second part of the tutorial which demonstrates Restful web service using Java, MySQL and JSON. In this tutorial we are going to create several REST clients for our web service. You can download each REST client project. Each REST client is going to parse the JSON response and display output.

Java REST client
Download
We use Java SE application as our client. To parse JSON, gson library is added to project /lib folder Also it is included in project build path as an external JAR.

Course.java – data bound model class

public class Course
{
private int id;
private String name;
private String duration;
private double fee;

public Course()
{

}

public Course(int id, String name, String duration, double fee)
{
super();
this.id = id;
this.name = name;
this.duration = duration;
this.fee = fee;
}

public int getId()
{
return id;
}

public void setId(int id)
{
this.id = id;
}

public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

public String getDuration()
{
return duration;
}

public void setDuration(String duration)
{
this.duration = duration;
}

public double getFee()
{
return fee;
}

public void setFee(double fee)
{
this.fee = fee;
}

@Override
public String toString()
{
return "Course [id=" + id + ", name=" + name + ", duration=" + duration
+ ", fee=" + fee + "]";
}

}

Main.java

package com;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

public class Main
{

/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception
{
String json = readUrl("http://localhost:8080/RestProject/Rest/courseService/courses");
Gson gson = new Gson();
JsonParser jsonParser = new JsonParser();
JsonArray courseArray = jsonParser.parse(json).getAsJsonArray();
List<Course> coursesList = new ArrayList<Course>();
for (JsonElement course : courseArray)
{
Course courseObj = gson.fromJson(course, Course.class);
coursesList.add(courseObj);
}

for (Course courseObj : coursesList)
{
System.out.println("ID : " + courseObj.getId());
System.out.println("Course Name : " + courseObj.getName());
System.out.println("Duration : " + courseObj.getDuration());
System.out.println("Course fee : " + courseObj.getFee());
}

}

private static String readUrl(String urlString) throws Exception
{
BufferedReader reader = null;
try
{
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while ((read = reader.read(chars)) != -1)
buffer.append(chars, 0, read);

return buffer.toString();
} finally
{
if (reader != null)
reader.close();
}

}
}

PHP REST client
CURL or file_get_contents() can be used to get JSONĀ  from the web service URL.

$json = file_get_contents("http://localhost:8080/RestProject/Rest/courseService/courses");
$json_o = json_decode($json);

$msg .= "";
foreach($json_o as $item)
{
$msg .= "Course ID : ". $item->id. "<br>";
$msg .= "Course Name : ". $item->name. "<br>";
$msg .= "DurationĀ  : ". $item->duration. "<br>";
$msg .= "Course fee : ". $item->fee. "<br><br>";
}
echo $msg;

$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, "http://localhost:8080/RestProject/Rest/courseService/courses");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
$json = curl_exec($ch);
$json_o = json_decode($json);

$msg .= "";
foreach($json_o as $item)
{
$msg .= "Course ID : ". $item->id. "<br>";
$msg .= "Course Name : ". $item->name. "<br>";
$msg .= "DurationĀ  : ". $item->duration. "<br>";
$msg .= "Course fee : ". $item->fee. "<br><br>";
}
echo $msg;

Android REST client

Download


 
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Posted by on November 28, 2012 in C#.Net, Java, PHP

 

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How to Display Current Date in your program

Find it difficult to get the current date and time? Then read on, I this tutorial I demonstrate getting current date and time in different programming languages.

Java

Using Calendar

output: 28/6/2012

  Calendar cal = new GregorianCalendar();
  int month = cal.get(Calendar.MONTH);
  int year = cal.get(Calendar.YEAR);
  int day = cal.get(Calendar.DAY_OF_MONTH);
  System.out.println("Current date : " + day + "/" + (month + 1) + "/" + year);

Using SimpleDateFormat

output: 28/06/2012

SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
Date date = new Date();
String sDate= sdf.format(date);

C#
Using DateTime format

output: Jun Fri 27 11:41 2012

DateTime time = DateTime.Now;              // Use current time
string format = "MMM ddd d HH:mm yyyy";    // Use this format
Console.WriteLine(time.ToString(format));

Some other patterns for DateTime
MMM : display three-letter month
ddd : display three-letter day of the WEEK
d : display day of the MONTH
HH : display two-digit hours on 24-hour scale
mm : display two-digit minutes
yyyy : display four-digit year

Single-letter format

output :
6/28/2012
Thursday, June 28, 2012
Thursday, June 28, 2012 11:36 AM
Thursday, June 28, 2012 11:36:21 AM
6/28/2012 11:36 AM
6/28/2012 11:36:21 AM
June 28
June 28
2012-06-28T11:36:21.8863219+05:30
2012-06-28T11:36:21.8863219+05:30
2012-06-28T11:36:21
11:36 AM
11:36:21 AM
2012-06-28 11:36:21Z
Thursday, June 28, 2012 6:06:21 AM
June, 2012
June, 2012

DateTime now = DateTime.Now;
Console.WriteLine(now.ToString("d"));
Console.WriteLine(now.ToString("D"));
Console.WriteLine(now.ToString("f"));
Console.WriteLine(now.ToString("F"));
Console.WriteLine(now.ToString("g"));
Console.WriteLine(now.ToString("G"));
Console.WriteLine(now.ToString("m"));
Console.WriteLine(now.ToString("M"));
Console.WriteLine(now.ToString("o"));
Console.WriteLine(now.ToString("O"));
Console.WriteLine(now.ToString("s"));
Console.WriteLine(now.ToString("t"));
Console.WriteLine(now.ToString("T"));
Console.WriteLine(now.ToString("u"));
Console.WriteLine(now.ToString("U"));
Console.WriteLine(now.ToString("y"));
Console.WriteLine(now.ToString("Y"));

Using Date strings to control the output

output:
Thursday, June 28, 2012
12:03:53 PM
6/28/2012
12:03 PM
6/28/2012 12:03:53 PM

DateTime now = DateTime.Now;
Console.WriteLine(now.ToLongDateString());
Console.WriteLine(now.ToLongTimeString());
Console.WriteLine(now.ToShortDateString());
Console.WriteLine(now.ToShortTimeString());
Console.WriteLine(now.ToString());

PHP

output : 2012-06-28 17:33:07

$date = date('Y-m-d H:i:s');
echo $date;

output : 2012/06/28 17:33:07

$date = date('Y/m/d H:i:s');
echo $date;

This time is based on the default server time zone. To get the time in a different time zone it should be set first.

date_default_timezone_set('Australia/Sydney');
$date = date('Y/m/d H:i:s');
echo $date;

JavaScript

output : Thursday, June 28, 2012

<script type="text/javascript"><!--
var now = new Date();
var Weekday = new Array("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday");
var Month = new Array("January","February","March","April","May","June","July","August","September","October","November","December");
document.write(Weekday[now.getDay()]+", "+Month[now.getMonth()]+" "+now.getDate()+", "+now.getFullYear());
//--></script>

output : 6/28/2012

<script type="text/javascript"><!--
var now = new Date();
document.write((now.getMonth()+1)+"/"+now.getDate()+"/"+now.getFullYear());
//--></script>

output : 06/28/2012

<script type="text/javascript"><!--
var now = new Date();
var month = now.getMonth()+1;
if( month < 9 ) { month = "0"+month; }
var day = now.getDate();
if( day < 9 ) { day = "0"+day; }
document.write(month+"/"+day+"/"+now.getFullYear());
//--></script>

ios

 NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
 [dateFormatter setDateFormat:@"hh:mm a"];   
 NSString *str_date = [dateFormatter stringFromDate:[NSDate date]];
 NSLog(@"str_date:%@",str_date);
 
 

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Save and Retrieve images in C# from SQL Database

Download Sourcecode

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;

namespace imageDB
{
public partial class Form1 : Form
{
DataSet ds;
string imageName;

public Form1()
{
InitializeComponent();
}

//Without using statements
/*private void insertData()
{
try
{

if (imageName != "")
{
//Initialize a file stream to read the image file
FileStream fs = new FileStream(@imageName, FileMode.Open, FileAccess.Read);
//Initialize a byte array with size of stream
byte[] imgByteArr = new byte[fs.Length];
//Read data from the file stream and put into the byte array
fs.Read(imgByteArr, 0, Convert.ToInt32(fs.Length));
fs.Close();

//Save binary data in database
string constr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\imageDB.mdf;Integrated Security=True;User Instance=True";
SqlConnection conn = new SqlConnection(constr);
conn.Open();
string sql = "insert into tbl_Image(id,img) values('" + textBox1.Text + "',@img)";

SqlParameter imageParameter = new SqlParameter();
imageParameter.SqlDbType = SqlDbType.Image;
imageParameter.ParameterName = "img";
imageParameter.Value = imgByteArr;
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add(imageParameter);
int result = cmd.ExecuteNonQuery();
if (result == 1)
{
MessageBox.Show("Image Added");
}

cmd.Dispose();
conn.Dispose();

}
}

catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}*/

private void insertData()
{
if (imageName == "")
{
return;
}

try
{
//Initialize a file stream to read the image file
FileStream fs = new FileStream(@imageName, FileMode.Open, FileAccess.Read);
//Initialize a byte array with size of stream
byte[] imgByteArr = new byte[fs.Length];
//Read data from the file stream and put into the byte array
fs.Read(imgByteArr, 0, Convert.ToInt32(fs.Length));
fs.Close();

//Save binary data in database
string constr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\imageDB.mdf;Integrated Security=True;User Instance=True";
using (SqlConnection conn = new SqlConnection(constr))
{
conn.Open();
string sql = "insert into tbl_Image(id,img) values('" + textBox1.Text + "',@img)";
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.Add(new SqlParameter("img", imgByteArr));
int result = cmd.ExecuteNonQuery();
if (result == 1)
{
MessageBox.Show("Image Added");
refreshImageList();
}
}
}
}
catch (Exception ex)
{

MessageBox.Show(ex.Message);
}
}

private void refreshImageList()
{
try
{
string connstr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\imageDB.mdf;Integrated Security=True;User Instance=True";

using (SqlConnection conn = new SqlConnection(connstr))
{
conn.Open();

using (SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM tbl_Image", conn))
{
ds = new DataSet("myDataSet");
adapter.Fill(ds);
DataTable dt = ds.Tables[0];

//Alternatively can fill data into a data table directly
//DataTable dt2 = new DataTable();
//adapter.Fill(dt2);

comboBox1.Items.Clear();

foreach (DataRow dr in dt.Rows)
{
comboBox1.Items.Add(dr["id"].ToString());
}
comboBox1.SelectedIndex = 0;

//Display queried data in a grid view
dataGridView1.DataSource = dt;
}
}

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

private void button1_Click(object sender, EventArgs e)
{
try
{

FileDialog fldlg = new OpenFileDialog();
fldlg.InitialDirectory = Environment.SpecialFolder.MyPictures.ToString();
fldlg.Filter = "Image File (*.jpg;*.bmp;*.gif)|*.jpg;*.bmp;*.gif";
if (fldlg.ShowDialog() == DialogResult.OK)
{
imageName = fldlg.FileName;
Bitmap bmp = new Bitmap(imageName);
pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
pictureBox1.Image = (Image)bmp;
}

fldlg = null;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString());
}
}

private void button2_Click(object sender, EventArgs e)
{
insertData();
}

private void button3_Click(object sender, EventArgs e)
{
DataTable dataTable = ds.Tables[0];
//If there is an already an image in picturebox, then delete it
if (pictureBox2.Image != null)
{
pictureBox2.Image.Dispose();
}

//Initialize a file stream to write image data
FileStream fs = new FileStream("image.jpg", FileMode.Create);

foreach (DataRow row in dataTable.Rows)
{
if (row[0].ToString() == comboBox1.SelectedItem.ToString())
{
//Store binary data read from the database in a byte array
byte[] blob = (byte[])row[1];

//Write data in image file using file stream
fs.Write(blob, 0, blob.Length);
fs.Close();
fs = null;

pictureBox2.Image = Image.FromFile("image.jpg");
pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
pictureBox2.Refresh();

}
}
}
}

}

 
3 Comments

Posted by on June 24, 2012 in C#.Net, SQL

 

Tags: ,