How to integrate Dynamic Image at JasperReport using java

This post is help full for integration dynamic image at jasper when your image data in blob or longblob in database.

there is following step to get your desire output:

Step-1: Make your field  in Jasper through palette:

Name:logo
field Class: java.lang.object

Step-2: Drop image box from palette and provide properties as:

Image Expression  :  net.sf.jasperreports.engine.util.JRImageLoader.loadImage((byte[])$F{logo})
Expression Class    java.awt.Image

Step-3: Java variable
         set logo as java.lang.Object datatype and set image data (byte[]) in logo variable .
              
               private Object logo;

Example:

 Java Code:
 
public class DemoJasperData{

private Object logo;

public Object getLogo() {
        return logo;
    }

    public void setLogo(byte[] yourImagebyteData) {
        this.logo = yourImagebyteData;
    }

}

.jrxml :

<field name="logo" class="java.lang.Object"/>
<image scaleImage="FillFrame">
                <reportElement x="9" y="8" width="100" height="98" uuid="053b21f7-00a3-4387-a6b3-c33475287f4c"/>
                <imageExpression><![CDATA[net.sf.jasperreports.engine.util.JRImageLoader.loadImage((byte[])$F{logo})]]></imageExpression>
            </image>

Now your dynamic image is ready on jesper Report

mailgun_validator.js for email validation

$.fn.mailgun_validator = function(options) {

    return this.each(function() {
        $(this).focusout(function() {

            run_validator($(this).val(), options);
        });

    });
};

function run_validator(address_text, options) {
    // don't run validator without input

    if (!address_text) {
        return;

    }
    // length check

    if (address_text.length > 512) {
        error_message = 'Stream exceeds maxiumum allowable length of 512.';

        if (options && options.error) {
           options.error(error_message);

        }
        else {

            console.log(error_message);
        }

        return;
    }


    // validator is in progress

    if (options && options.in_progress) {
        options.in_progress();

    }
    // require api key

    if (options && options.api_key == undefined) {
        console.log('Please pass in api_key to mailgun_validator.')

    }
    var success = false;


    // make ajax call to get validation results

    $.ajax({
        type: "GET",

        url: 'https://api.mailgun.net/v2/address/validate?callback=?',
        data: { address: address_text, api_key: options.api_key },

        dataType: "jsonp",
        crossDomain: true,

        success: function(data, status_text) {
           success = true;

            if (options && options.success) {
                options.success(data);

            }
        },

        error: function(request, status_text, error) {
            success = true;

            error_message = 'Error occurred, unable to validate address.';
            if (options && options.error) {

                options.error(error_message);
            }

            else {
               console.log(error_message);

            }
        }

    });
    // timeout incase of some kind of internal server error

    setTimeout(function() {
        error_message = 'Error occurred, unable to validate address.';

        if (!success) {
            if (options && options.error) {

                options.error(error_message);
            }

            else {
                console.log(error_message);

            }
        }

    }, 30000);
}

email validation

Here we use an "mailgun_validator.js"  for email validation .  

 //Html Code  
<form>

      <div>

        <label for="email">Email address</label><br>
        <input type="email" name="email" id="email">
        <div id="status"></div>
      </div>
      <div>
        <button type="submit" id="validate_submit">Validate</button>
      </div>
 </form> 
//java script       
            <script src="mailgun_validator.js"></script>

// document ready 

      $(function() {
  // capture all enter and do nothing
        $('#email').keypress(function(e) {
          if(e.which == 13) {
           $('#email').trigger('focusout');
           return false;
          }
        });
 // capture clicks on validate and do nothing
        $("#validate_submit").click(function() {
          return false;
        });
 // attach jquery plugin to validate address
        $('#email').mailgun_validator({
          api_key: 'MAILGUN_PUBKEY', // replace this with your Mailgun public API key
          in_progress: validation_in_progress,
          success: validation_success,
          error: validation_error,
        });
      });
// if email successfull validated

      function validation_success(data) {

        $('#status').html(get_suggestion_str(data['is_valid'], data['did_you_mean']));
      }
 // if email is invalid
      function validation_error(error_message) {
        $('#status').html(error_message);
      }
 // suggest a valid email
      function get_suggestion_str(is_valid, alternate) {
        if (alternate) {
          return '<span class="warning">Did you mean <em>' +  alternate + '</em>?</span>';
        } else if (is_valid) {
          return '<span class="success">Address is valid.</span>';
        } else {
          return '<span class="error">Address is invalid.</span>';
        }
      }
MAILGUN_PUBKEY: pubkey-5ogiflzbnjrljiky49qxsiozqef5jxp7










 

Java keyword: assert

The assert keyword is used in assert statement which is a feature of the Java programming language since Java 1.4. Assertion enables developers to test assumptions in their programs as a way to defect and fix bugs.

Syntax of assert statement

 Syntax of an assert statement is as follow (short version):

assert expression1;

or (full version):

assert expression1 : expression2;

Where:

• expression1 must be a boolean expression.
• expression2 must return a value (must not return void).

The assert statement is working as follows:

• • If assertion is enabled, then the assert statement will be evaluated. Otherwise, it does not get executed.
  • If expression1 is evaluated to false, an AssertionError error is thrown which causes the program stops immediately. And depending on existence of expression2:

• • • If expression2 does not exist, then the AssertionError is thrown with no detail error message.
    • If expression2 does exist, then a String representation of expression2’s return value is used as detail error message.

• • If expression1 is evaluate to true, then the program continues normally.

Enable assertion

By default, assertion is disabled at runtime. To enable assertion, specify the switch –enableassertions or -ea at command line of java program. For example, to enable assertion for the program called CarManager:

java –enableassertions CarManager

or this for short:

java –ea CarManager

Assertion can be enabled or disable specifically for named classes or packages.

Assertion examples

 The following simple program illustrates the short version of assert statement:

AssertionExample {

   


 public static void main(String[] args) {
 


      

 // get a number in the first argument




       

 int number = Integer.parseInt(args[0]);

 



        assert number <= 10; // stops if number > 10


 



        System.out.println("Pass");


    }




}

 When running the program above with this command:

java -ea AssertionExample 15

A java.lang.AssertionError error will be thrown:

Exception in thread "main" java.lang.AssertionError

       at AssertionExample.main(AssertionExample.java:6)

But the program will continue and print out “Pass” if we pass a number less than 10, in this command:

java -ea AssertionExample 8

And the following example is using the full version of assert statement:

public class AssertionExample2 {


    public static void main(String[] args) {
 


        int argCount = args.length;
 


        assert argCount == 5 : "The number of arguments must be 5";
 


        System.out.println("OK");
 


    }


}

 When running the program above with this command:

java -ea AssertionExample2 1 2 3 4

it will throw this error:

Exception in thread "main" java.lang.AssertionError: The number of arguments must be 5

       at AssertionExample2.main(AssertionExample2.java:6)

Generally, assertion is enabled during development time to defect and fix bugs, and is disabled at deployment or production to increase performance.