In earlier tutorials, we’ve developed different types of Portlet. at once and then we learned using of . This time we’re going to develop a Portlet using another famous framework like Apache Struts.
is an MVC-based one, we’ve already covered a lot of topics onto Apache Struts as you can refer for all of them, but this is the first time you will get a Struts application deployed into a Portlet container like Apache Pluto.
You’re likely going to use Apache Struts Bridge that is already maintained by Apache itself. However, the same application that you’ve implemented before (Employee Registration Form) will be used in this tutorial but with Struts2 framework.
The main goal of this application is to help you know all the details required for getting the application deployed and running properly onto any JSR-168/JSR-286 compliant Portlet container.
Let’s see the Employee entity (Model) that would be used for holding the data that are going back and forth between the application and the database store.
package com.journaldev.data;public class Employee { private String id; private String name; private String job; private String salary; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getSalary() { return salary; } public void setSalary(String salary) { this.salary = salary; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getJob() { return job; } public void setJob(String job) { this.job = job; }}
使用Eclipse IDE创建模板应用程序 (Create Template Application Using Eclipse IDE)
You may save your time instead of getting delve into creating the project by yourself, by using an Apache Struts Archetype. Following steps will help you creating a Struts Portlet application easily.
Add Remote Archetype Catalog https://struts.apache.org/ into your Maven Archetypes. 将远程原型目录https://struts.apache.org/添加到您的Maven原型中。
Create a new Maven project. This time you will get stopped into Catalog selection, instead of using All Catalogs, you must select that’s one registered. 创建一个新的Maven项目。 这次您将停止进入目录选择，而不必使用所有目录，而必须选择已注册的目录。
Fill in the all required information, GroupId, ArtifactId, version, and Package. 填写所有必需的信息，GroupId，ArtifactId，版本和包。
Click Finish and waiting your Eclipse displaying created application into your Project Explorer. 单击完成，然后等待Eclipse将创建的应用程序显示到项目资源管理器中。
Though the application is created successfully, but it’s likely want some of in-hand adjustment as the Archetype’s Maven dependencies isn’t updated somehow. That’s why you may notice some errors in the created application. 尽管已成功创建了应用程序，但由于未对Archetype的Maven依赖项进行更新，因此可能需要进行一些手动调整。 因此，您可能会在创建的应用程序中发现一些错误。
Delete all undesired Java files under com.journaldev package. 删除com.journaldev软件包下的所有不需要的Java文件。
Delete all undesired JSP files/folders under WEB-INF/jsp. 删除WEB-INF / jsp下所有不需要的JSP文件/文件夹。
修改Maven依赖项 (Modify Maven Dependencies)
The Maven dependency file has got modified to serve two wanted features:
Maven依赖项文件已修改为提供两个所需功能：
Add required dependencies for Struts2 and its relevant Portlet container Bridge. 为Struts2及其相关的Portlet容器Bridge添加所需的依赖关系。
Add all required Apache Pluto accompanies that would lead us for a healthy deployment onto Apache Pluto itself. 添加所有必需的Apache Pluto随附文件，这些文件将引导我们在Apache Pluto本身上进行良好的部署。
As you may know, Apache Struts has considered JSP as a view technology, so we would add a three distinct files, register.jsp, success.jsp and failure.jsp.
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><%@ taglib prefix="s" uri="/struts-tags" %> FailureUnfortunately! The Employee hasn't been registered successfully">Try Again!
success.jsp
success.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><%@ taglib prefix="s" uri="/struts-tags" %> SuccessCongratulations! The Employee has been registered successfully">Register Another
As you’ve noticed, we used a for providing a form component and its relevant parameters. If you’re not so good with a Struts, it’s so good for you return here to read some articles about it as it’s very elegant framework.
Struts Tag library has provided a <url/> Tag for creating a Struts-based link. Struts-based link is a link that uses the Struts framework vocabulary like action.
One important thing you should notice that and it’s the action attribute for the form that’s referred for action it’s name is register. That name would be provided by the struts.xml file that would be discussed later on.
It’s may be known for you that a . In that, every form submission should be delegated into action based class that’s implemented to be extended from DefaultActionSupport class. Following RegisterAction Struts action class.
package com.journaldev.action;import java.io.IOException;import java.sql.SQLException;import javax.portlet.PortletPreferences;import org.apache.log4j.Logger;import org.apache.struts2.dispatcher.DefaultActionSupport;import org.apache.struts2.portlet.interceptor.PortletPreferencesAware;import com.journaldev.dao.EmployeeDAO;import com.journaldev.data.Employee;public class RegisterAction extends DefaultActionSupport implements PortletPreferencesAware { private static Logger logger = Logger.getLogger(RegisterAction.class); private static final long serialVersionUID = 1L; private PortletPreferences preferences; private String id; private String name; private String job; private String salary; public PortletPreferences getPreferences() { return preferences; } public void setPreferences(PortletPreferences preferences) { this.preferences = preferences; } @Override public void setPortletPreferences(PortletPreferences prefs) { this.preferences = prefs; } @Override public String execute() throws Exception { try { Employee employee = new Employee(); employee.setId(id); employee.setName(name); employee.setJob(job); employee.setSalary(salary); // Register Employee employee = EmployeeDAO.getInstance().createEmployee(employee); logger.debug("Employee Has Registered"); return "SUCCESS"; } catch (IllegalAccessException | ClassNotFoundException | SQLException | IOException e) { logger.debug("Registration Process Has Failed",e); return "FAILURE"; } } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getJob() { return job; } public void setJob(String job) { this.job = job; } public String getSalary() { return salary; } public void setSalary(String salary) { this.salary = salary; }}
Here’s detailed explanation for the RegisterAction class figured out:
这里是对RegisterAction类的详细说明：
Notice the class’s properties id, name, job and salary are analogous for these parameters’ names that are provided by the register.jsp page. 请注意，类的属性id，名称，工作和薪水与register.jsp页面提供的这些参数的名称相似。
RegisterAction has overridden an execute method for serving the employee registration purposes. RegisterAction已覆盖用于服务员工注册目的的execute方法。
Struts framework will binded all form’s parameters with those corresponding ones at the action class. Id, name, job and salary will be passed automatically. Struts框架会将所有表单的参数与动作类中的那些对应参数绑定在一起。 ID，姓名，工作和薪水将自动传递。
RegisterAction has used the EmployeeDAO (The same utility class that we’ve impelemnted previously, that it would handle the all database manipulation code) for registering the employee instance. RegisterAction使用EmployeeDAO（我们之前介绍的相同的实用程序类，它将处理所有数据库操作代码）注册员工实例。
In case the registration process has failed the Struts framework would take you into failure page. The page success.jsp is that one, the Struts framework will redirect you into as soon as the registration has finished successfully. 如果注册过程失败，Struts框架会将您带到失败页面。 一旦成功完成注册，Struts框架就会将页面success.jsp重定向到该页面。
Wiring of mentioned actions within your <s:form/> with the Struts-action must be defined as an entries within struts.xml file. Following Struts configuration file required:
Integration of Apache Struts with the given Portlet container has been done through using of portlet.xml file. In that, a new init-param should be used for this purpose. Following the Portlet.xml file that’s used.
Register Employee RegisterEmployee org.apache.struts2.portlet.dispatcher.Jsr286Dispatcher actionPackages com.journaldev.action viewNamespace /employee defaultViewAction index text/html view en Register Employee Register Employee Employee,Registration
Here’s detailed explanation for both of the Struts and Portlet configuration files listed above:
这是上面列出的Struts和Portlet配置文件的详细说明：
Your Portlets must be an instance of JSR286Dispatcher class. 您的Portlet必须是JSR286Dispatcher类的实例。
We’ve defined three additional parameters, actionPackages, viewNamespace and defaultViewAction. 我们定义了三个附加参数，actionPackages，viewNamespace和defaultViewAction。
Defined defaultViewAction will be used once you’ve opened the Portal page that’s contained the deployed Portlet. As being index is the value, the index should be defined as an action in the struts.xml file. 打开包含已部署Portlet的Portal页面后，将使用已定义的defaultViewAction 。 由于索引是值，因此应该将索引定义为struts.xml文件中的操作。
Defined actionPackages will be used for determining the Java package that contains the Struts-actions classes. 定义的actionPackages将用于确定包含Struts-actions类的Java包。
Defined viewNamespace will determine the namespace for the actions configured for view mode. It’s also applicable to define actions for edit and help modes. 定义的viewNamespace将确定为view mode配置的动作的名称空间。 它也适用于定义edit和help模式的动作。
Struts configuration file has defined an register action that would be used as soon as the user has submitted the form’s register. Struts配置文件已定义一个register动作，用户提交表单的注册后将立即使用该动作。
Defined register action has had two different results, success and failure are used to determine the next view that Struts framework uses after finishing the calling of execute against action class. 定义的register动作具有两个不同的结果，成功和失败用于确定在完成针对动作类的execute调用之后Struts框架使用的下一个视图。
package com.journaldev.dao;import java.io.IOException;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.SQLException;import com.journaldev.dao.utility.ConnectionUtility;import com.journaldev.data.Employee;public class EmployeeDAO { public static EmployeeDAO employeeDAO = null; private EmployeeDAO(){ } public static EmployeeDAO getInstance(){ synchronized(EmployeeDAO.class){ if(employeeDAO == null){ employeeDAO = new EmployeeDAO(); } } return employeeDAO; } public Employee createEmployee(Employee employee) throws SQLException, IllegalAccessException, IOException, ClassNotFoundException{ // Get connection instance Connection connection = ConnectionUtility.getInstance().getConnection(); // Create Prepared Statement PreparedStatement query = connection.prepareStatement("INSERT INTO EMPLOYEE VALUES (?,?,?,?)"); // Set variables query.setInt(1, Integer.parseInt(employee.getId())); query.setString(2, employee.getName()); query.setString(3, employee.getJob()); query.setInt(4, Integer.parseInt(employee.getSalary())); try { // Execute query.execute(); // Return employee instance return employee; } catch(Exception e){ // Close statement query.close(); // Close connection connection.close(); // Throw another exception for notifying the Servlet throw new SQLException(e); } } public boolean deleteEmployee(Employee employee){ return false; } public boolean updateEmployee(Employee employee, int employeeId){ return false; }}
package com.journaldev.dao.utility;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.util.Properties;public class ConnectionUtility { private static ConnectionUtility connectionUtiliy = null; private Connection connection = null; private ConnectionUtility() { } public static ConnectionUtility getInstance() throws IOException, IllegalAccessException, SQLException, ClassNotFoundException{ // Synchronized against connectionUtility instance synchronized(ConnectionUtility.class){ // Check whether the connectionUtility is null or not if(connectionUtiliy == null){ // Create a properties instance Properties properties = new Properties(); // Load properties from classpath properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("connection.properties")); // Set connection with connectionUtility connectionUtiliy = new ConnectionUtility(); // Load driver class Class.forName("com.mysql.jdbc.Driver"); // Create connection connectionUtiliy.setConnection(DriverManager.getConnection("jdbc:mysql://localhost:3306/journaldev", properties)); } return connectionUtiliy; } } public Connection getConnection() throws ClassNotFoundException, SQLException, IOException { if(connection.isClosed()){ // Create a properties instance Properties properties = new Properties(); // Load properties from classpath properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("connection.properties")); // Load driver class Class.forName("com.mysql.jdbc.Driver"); // Create connection connectionUtiliy.setConnection(DriverManager.getConnection("jdbc:mysql://localhost:3306/journaldev", properties)); } return connection; } public void setConnection(Connection connection) { this.connection = connection; }}
注册员工演示 (Registration Employee Demo)
To get started showing your Portlet, you must logged into your Apache Pluto and navigating into JournalDev page. Typically, we have added a Portal page that’s contained for our developed Portlet. The process of creating a Portal page and add the Portlets upon it is discussed at .
Apache Struts is an elegant framework that’s used for creating an MVC-based enterprise application. Apache has also provided you a ready made Portlet bridge that could be used for creating JSR-168/286 Struts-based Portlet. Contribute us by commenting below and find the downloaded source code.