Friday, July 4, 2014

Ignoring the Host Name verification while invoking the HTTPS service through HttpsURLConnection

Ignoring the Host Name verification while invoking the HTTPS service through HttpsURLConnection

Sometimes you may receive the Host Name mismatch exception while invoking the HTTPS service from the Java client even though the valid certificate is installed to the key store.

javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No name matching <Host Name> found

The root cause of the exception is the CN name of the certificate is not matching with the host name used to connect the service.

In real scenario while the certificate is signed with third party certificate authority , the CN name will be specified as the host name of the server where the service is hosted or wildcard name will be specified e.g *.example.com to represent all sub domains in a domain. So there will not be any issue while connecting to the service.

This mismatch exception will happen most of the time communicating with self signed certificate, the certificate is signed with CN name that is not matching with the host name.

How to Fix the issue

To resolve the issue, the certificate should be signed with proper CN name or we can create a custom host name verifier to customize the host name verification functionality.

We have to return true from the custom host name verifier for the host name for which the CN name is mismatching.This will connect to the service irrespective of the host name used .

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.HttpURLConnection;

public class HTTPCaller {
static {
   javax.net.ssl.HttpsURLConnection.setDefaultHostnameVerifier(
   new javax.net.ssl.HostnameVerifier(){
       public boolean verify(String hostname,
               javax.net.ssl.SSLSession sslSession) {
           if (hostname.equals("localhost")) {
               return true;
           }
           return false;
       }
   });
}

    public static String execute() {
        String targetURL="https://localhost/test"
        URL url;
        HttpURLConnection connection = null;
        try {
            url = new URL(targetURL);
            url = new URL(url.toString());              

            connection = (HttpURLConnection)url.openConnection();
            connection.setRequestProperty("accept", "application/xml"); //for GET service to return xml payload

            InputStream is = connection.getInputStream();
            BufferedReader rd = new BufferedReader(new InputStreamReader(is));
            System.out.println("\n Received response" + System.currentTimeMillis());

            String line;
            StringBuffer response = new StringBuffer();
            while ((line = rd.readLine()) != null) {
                response.append(line);
                response.append('\r');
            }
            rd.close();
            return response.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return (e.getClass().getName()+":"+e.getMessage().toString());
        }
        finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }



Wednesday, July 2, 2014

Encrypting XML Payload through XSLT in Spring WS

Encrypting XML Payload through XSLT in Spring WS

The below document explain the approach to This document will explain the approach to encrypt the critical elements of XML payload while invoking the services in Spring WS or storing the data to a database table through XSLT.



Encrypting_XML_Payload.pdf


Tuesday, July 1, 2014

Unit Testing the Velocity Templates in spring

Unit Testing the Velocity Templates in spring

It is painful to test the Velocity Template  by deploying to the server while doing frequent changes.
The unit testing  will help as to overcome this and do proper testing without deploying the project to the server.
This post will explain the approach to unit test the Velocity Templates through eclipse.

Spring velocity configurations

Create a Velocity-test.xml configuration file to configure the velocity bean - instead of creating separate configuration file we can also use the project configuration file that has the velocity bean configuration (e.g. application-context.xml)


Change the vm template path accordingly.

Create a test java class (VelocityTest.java)

import java.io.*;
import java.util.ArrayList;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.*;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.thomson.ecom.core.velocity.VelocityContextBuilder;
public class VelocityTest
{
public static void main(String[] args) throws Exception
{
ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:velocity-test.xml");
ArrayList<Employee> employeeList=new ArrayList<Employee>();

Employee emp1=new Employee();
emp1.setContactNo("111111");
emp1.setDept("CSC");
emp1.setEmail("a@gmail.com");
emp1.setEmpName("Albin");
emp1.setEmpNo("1");
emp1.setLocation("Bangalore");
employeeList.add(emp1);

Employee emp2=new Employee();
emp2.setContactNo("22222");
emp2.setDept("IT");
emp2.setEmail("b@gmail.com");
emp2.setEmpName("Albin1");
emp2.setEmpNo("2");
emp2.setLocation("Bangalore");
employeeList.add(emp2);

Employee emp3=new Employee();
emp3.setContactNo("33333");
emp3.setDept("IT");
emp3.setEmail("c@gmail.com");
emp3.setEmpName("Albin2");
emp3.setEmpNo("3");
emp3.setLocation("Bangalore");
employeeList.add(emp3);

VelocityEngine engine = ctx.getBean("velocityEngine", VelocityEngine.class);
Context velocityCtx = VelocityContextBuilder.getInstance().buildContext();
velocityCtx.put("empList", employeeList);

Writer w = new FileWriter(new File("D:\\Albin\\velocity.html"));
engine.mergeTemplate("EmployeeEmailTemplate.vm", velocityCtx, w);
w.close();

System.exit(0);
}
}

Change the velocity.html file path and the vm template name accordingly.
Pass the required inputs to the velocityCtx map.
Execute the VelocityTest.java; this will generate the velocity.html file in the specified location.



Resolving cvc-elt.1: Cannot find the declaration of element 'beans' in Spring

Resolving cvc-elt.1: Cannot find the declaration of element 'beans' in Spring

I was receiving the following exception while running the Spring application in standalone mode with maven and eclipse.

Exception in thread "main" org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 11 in XML document from class path resource [encrypt/encrypting-test.xml] is invalid; nested exception is org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'beans'.
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:396)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143)

Caused by: org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'beans'.
at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
at org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)

Unfortunately i could not able to find any issue in my bean configuration file.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd">

<bean id="encryptXMLPayload" class="com.encrypt.EncryptXMLPayload">
<property name="encryptor" ref="encryptor" />
<property name="messageStylesheet" value="classpath:encrypt/encryptXMLPayload.xslt" />
</bean>

<bean id="encryptor" class="com.encrypt.Encryptor" init-method="init">
<property name="keyData" value="pYOkcj4_kf-4hn-A-IkclLWDBJI-T5bd"/>
</bean>
</beans>

After analysis the issue is with version mismatch between the pom.xml(spring version configured) and the schema version  configured in the bean configuration file

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>3.0.0.RELEASE</version>
<scope>compile</scope>
</dependency>

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd">

How to Fix

The issue got resolved after changing the schema version to 3.0 in the bean configuration file as shown below

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">

The spring version configured in the pom.xml and the schema version used in the bean configuration files should be matching.


Loading configuration properties from Database Table in Spring Application

Loading configuration properties from Database Table in Spring Application

This is better approach to store the configuration properties to a database table so that this can be managed easily.
This post will explains the approach to store and retrieve the configuration properties from database table in spring project.

Bean definition in Spring context file:

Configure the below bean definition to the spring context file

<!--  Loads properties to set environment-specific values within the DB table for that environment -->
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="properties">
<bean class="org.apache.commons.configuration.ConfigurationConverter"
factory-method="getProperties">
<constructor-arg>
<bean class="org.apache.commons.configuration.DatabaseConfiguration">
  <constructor-arg>
  <ref bean="propertyDataSource"/>
</constructor-arg>
     <constructor-arg value="Properties"/>  <!--  DB Table -->
     <constructor-arg value="prop_key"/> <!-- DB Key Column -->
   <constructor-arg value="prop_value"/> <!--  DB Value Column -->
   </bean>
</constructor-arg>
</bean>
</property>
</bean>

Properties database table

The Properties database table should be pre-created with the required configuration values

Prop_keyProp_value
ftp.hostlocalhost
ftp.useralbin

Data source configuration

The datasource ref bean  propertyDataSource should be configured in the spring context file.

<jee:jndi-lookup id="propertyDataSource" jndi-name="java:comp/env/jdbc/propertyDS"/>

Here i am using the Tomcat server, the actual datasource - jdbc/propertyDS should be configured in context.xml file of the Tomcat server.

<Resource name="jdbc/propertyDS "
auth="Container"
type="javax.sql.DataSource"
username="property_user"
password="property "
driverClassName="com.microsoft.sqlserver.jdbc.SQLServerDriver"
url="jdbc:sqlserver://localhost:1433;DatabaseName=Soa"
maxActive="4"
maxIdle="2"/>

Refer the properties

Now the properties can be referred as shown below

<bean id="ftp" class="com.doc.FTPService">
<property name="host" value="${ftp.host}"/>
<property name="user" value="${ftp.user}"/>
</bean>