LearnJava: October 2016

Friday, 21 October 2016

How to send Mail in Java

package com.sendMail;

import java.io.FileInputStream;
import java.util.Properties;

import javax.mail.Address;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

/**
*
* @author ananddw
*
*/

public class EmailService {

public boolean SendMail(String voucherID){

   boolean flag=false;
    Properties props = System.getProperties();
    props.put("mail.smtp.host", "smtp.gmail.com"); //SMTP Host
    props.put("mail.smtp.port", "587"); //TLS Port
    props.put("mail.smtp.auth", "true"); //enable authentication
    props.put("mail.smtp.starttls.enable", "true"); //enable STARTTLS

    StringBuilder mailBody = new StringBuilder("Hi,<br/><br/>");
   mailBody.append("Mail is Created Succesfully<br/><br/>");
   mailBody.append(" Time: " + System.currentTimeMillis() + ""+ "<br/><br/>");

   mailBody.append("Send By : Anand <br/><br/><br/>");
   mailBody.append("Thanks & Regards<br/>Anand Dwivedi");

    Session session = Session.getInstance(props,null);
    MimeMessage message = new MimeMessage(session);

    System.out.println("Port: "+session.getProperty("mail.smtp.port"));

    // Create the email addresses involved
    try {
       String [] mailTo=new String[] {"test@gmail.com" };
       InternetAddress[] addressTo = new InternetAddress[mailTo.length];
       for (int i = 0; i < mailTo.length; i++) {
           addressTo[i] = new InternetAddress(mailTo[i]);
           addressTo[i].validate();
       }
        InternetAddress from = new InternetAddress("test@gmail.com");
        message.setSubject(" Message Mail");
        message.setFrom(from);
        message.addRecipients(Message.RecipientType.TO,addressTo);

        // Create a multi-part to combine the parts
        Multipart multipart = new MimeMultipart("alternative");

        // Create your text message part
        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText("some text to send");

        // Add the text part to the multipart
        multipart.addBodyPart(messageBodyPart);

        // Create the html part
        messageBodyPart = new MimeBodyPart();
        String htmlMessage = mailBody.toString();
        messageBodyPart.setContent(htmlMessage, "text/html");

        // Add html part to multi part
        multipart.addBodyPart(messageBodyPart);

        // Associate multi-part with message
        message.setContent(multipart);

        // Send message
        Transport transport = session.getTransport("smtp");
        transport.connect("smtp.gmail.com", "test@gmail.com", "Gmail password");
        System.out.println("Transport: "+transport.toString());
        transport.sendMessage(message, message.getAllRecipients());

        flag=true;
    } catch (AddressException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        flag=false;
    } catch (MessagingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        flag=false;
    }
    return flag;
}

public static void main(String []args){
EmailService service=new EmailService();
service.SendMail();
}
}

PS: Make sure that attache all the required Jars as well as

Turn On This service if it is off: https://www.google.com/settings/security/lesssecureapps

Sunday, 9 October 2016

Action Message and Action Error in Struts2

Find below code to check how action Error and Action Message is working in Struts2

####login.jsp

<%--
Document : login
Created on : Oct 09, 2016, 2:50:34 PM
Author : shiboo
--%>
<!DOCTYPE html>
<%@taglib uri="/struts-tags" prefix="s"%>
<html>
<head>
<title>Login</title>
</head>
<body>
<center><h3>ActionMessage Example</h3>
<s:actionerror />
<s:form action="login">
<s:textfield name="userName" label="Username" />
<s:password name="password" label="password" />
<s:submit value="Login" />
</s:form>
</center>

</body>

</html>

####success.jsp

<%--
Document : success
Created on : Oct 09, 2016, 2:41:34 PM
Author : shiboo
--%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<title>Welcome Page</title>
</head>
<body>
<h3>ActionError & ActionMessage Examples</h3>
<s:actionmessage />
</body>
</html>

###Struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="default" extends="struts-default">
<action name="login" class="com.Messageaction.LoginAction">
<result name="success">success.jsp</result>
<result name="input">login.jsp</result>
</action>
</package>
</struts>

###LoginAction.java

package com.Messageaction;
import com.opensymphony.xwork2.ActionSupport;

/**
*
* @author shiboo
*
*/
public class LoginAction extends ActionSupport {

private static final long serialVersionUID = 6677091252031583948L;
private String userName;
private String password;

public String execute() {

return SUCCESS;
}

public String getUserName() {
return userName;
}

public void setUserName(String userName) {
this.userName = userName;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public void validate() {

if (userName.isEmpty()) {
addActionError("Username is not blanked");
} else {
if(password.isEmpty()){
addActionError("Password is not blanked");
}else{
addActionMessage("Welcome " + userName);
}}
}
}

#### web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

<display-name>Struts2</display-name>

<filter-name>struts2</filter-name>

<filter-class>

org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>struts2</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<welcome-file-list>

<welcome-file>login.jsp</welcome-file>

</welcome-file-list>

</web-app>

Please find below screenshot

Friday, 7 October 2016

Hibernate Application Java

Hibernate framework simplifies the development of java application to interact with the database. Hibernate is an open source, lightweight tool.

An ORM tool simplifies the data creation, data manipulation and data access. It is a programming technique that maps the object to the data stored in the database.

Example

Student.java

package com.hibernate;
/**
*
* @author ananddw
*
*/
public class Student {

    private int id;
    private String studentName;
    private String studentPlace;

    //Setter and Getters

    public int getId() {
       return id;
    }
    public void setId(int id) {
       this.id = id;
    }
    public String getStudentName() {
       return studentName;
    }
    public void setStudentName(String studentName) {
       this.studentName = studentName;
    }
    public String getStudentPlace() {
       return studentPlace;
    }
    public void setStudentPlace(String studentPlace) {
       this.studentPlace = studentPlace;
    }



}

==========StudentResourc.java ====================
package com.hibernate;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

/**
*
* @author ananddw
*
*/
public class StudentResource {
public static void main(String[] args) {
    StudentResource studentresrouce=new StudentResource();
    studentresrouce.saveObject();
}
public boolean saveObject(){
    boolean flag=false;
try{
Configuration cfg=new Configuration();
cfg.configure("hibernate.cfg.xml");
SessionFactory factory=cfg.buildSessionFactory();
Session session=factory.openSession();
Transaction t=session.beginTransaction();

Student student = new Student();
student.setId(3);
student.setStudentName("Rahul");
student.setStudentPlace("Mumbai");
session.saveOrUpdate(student);

t.commit();
session.close();

System.out.println("successfully saved");
}catch(Exception e){
    e.printStackTrace();
    flag=false;
}
return flag;
}
}

=============hibernate.cfg.xml ========================

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.url">jdbc:postgresql://127.0.0.1:5432/hibernate</property>
        <property name="hibernate.connection.username">postgres</property>
        <property name="hibernate.connection.password">password</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
        <property name="hibernate.hbm2ddl.auto">update</property>

        <mapping resource="com/hibernate/student.cfg.xml" />

    </session-factory>
</hibernate-configuration>

==================student.cfg.xml=============

<?xml version='1.0' encoding='UTF-8'?>
    <!DOCTYPE hibernate-mapping PUBLIC
     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
     "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

     <hibernate-mapping>
      <class name="com.hibernate.Student" table="student">
        <id name="id">
         <generator class="native"></generator>
        </id>

        <property name="studentName"></property>
        <property name="studentPlace"></property>

      </class>

     </hibernate-mapping>

PS: Please Add Required Jars to run hibernate Application

hibernate3.jar
dom4j-1.6.1.jar
commons-logging-1.1.1.jar
commons-collections-2.1.1.jar
postgresql-8.3-603.jdbc3.jar
cglib-2.1_3.jar
cglib-nodep-2.1_3.jar
asm-1.5.2.jar
asm-analysis-1.5.2.jar
asm-attrs-1.5.2.jar
asm-tree-1.5.2.jar
asm-util-1.5.2.jar
asm-xml-1.5.2.jar
jta.jar
antlr.jar

Sunday, 2 October 2016

Reverse String in Java

How to reverse String in Java without using external function . here is the easiest way to reverse String in java


public class ReverseString{
    public static void main(String []args){
        String value="Anand";
        for(int i=value.length()-1;i>=0;i--){
            System.out.println(value.charAt(i));
            
        }
    }
}

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