Serve static resources from external folder outside webapps tomcat

This is quite an important blog for all folks who is looking on how to serve static content from a location on a disk which is completely outside of the webapps folder in Apache Tomcat. This method is quite useful to server images, JS, CSS, PDFs and even static HTML web pages.

Tomcat will serve any static content from a WAR file using the DefaultServlet. This works great for serving files that are bundled with your Java code inside of a WAR file – it’s fast enough for most purposes and it just works, but with one major drawback: you have to re-deploy the WAR file if you want to add or amend a static file.

Tomcat can be configured to read files from anywhere on the disk and serve on a specific URL. This configuration is completely separate to our application configuration.

You just need to change a single file server.xml that resides under $CATALINA_HOME/config/server.xml.

Just open the server.xml file and make the changes like below.

Remember: You need to take bounce of server after the making the changes to take effect of the changes.

<Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true">
   
  <Context docBase="C:\Ankur\testFiles"  path="/companyLogo" />

       <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
               prefix="localhost_access_log" suffix=".txt"
               pattern="%h %l %u %t &quot;%r&quot; %s %b" />

</Host>

A <context>  element is added inside the <HOST>  element. Context has two attributes: docBase is the directory on disk that contains your static files and path is the URL that you want to serve the files on. 

Make sure that Tomcat has access to read the files in docBase. Using the example server.xml snippet above, if we had an image in C:\Ankur\testFiles called test.png then we would be able to access it via local Tomcat instance using http://localhost:8081/companyLogo/test.png.

Let's see the example below:

1) Put files inside the C:\Ankur\testFiles directoy

2) Hit the URL: http://localhost:8081/companyLogo/7.png and see the result:

That's it !!

Spring MVC RESTful web service for file upload

This is one of the common requirement in all the project to upload a file. In the blog, we are gonna to show you the complete example how to create a REST service in Spring that will be used to upload any type of file.

After this blog,  you have learned to how to create REST web service that will take file as a input parameter and upload to any one of the location.

More blogs:

RESTFul API in Spring MVC : CRUD Operation

Secure RESTFul API using OAuth2 : Spring

Download project from here

Tools and Technologies used in this project

1. Apache Maven 3.0.4
2. JDK 1.8
3. Spring 4.2.5.RELEASE
4. commons fileupload 1.3.1
5. Eclipse
6. Tomcat 8.0.38

Project Structure:

pom.xml

As we are using maven project. Let's define the spring specific maven dependencies.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

 <modelVersion>4.0.0</modelVersion>

 <groupId>FileUpload</groupId>

 <artifactId>FileUpload</artifactId>

 <version>0.0.1-SNAPSHOT</version>

 <packaging>war</packaging>

 <name>FileUpload</name>

 <properties>

  <java-version>1.8</java-version>

  <org.springframework-version>4.2.5.RELEASE</org.springframework-version>

  <failOnMissingWebXml>false</failOnMissingWebXml>



 </properties>

 <dependencies>

  <!-- Apache Commons FileUpload -->

  <dependency>

   <groupId>commons-fileupload</groupId>

   <artifactId>commons-fileupload</artifactId>

   <version>1.3.1</version>

  </dependency>



  <!-- Apache Commons IO -->

  <dependency>

   <groupId>commons-io</groupId>

   <artifactId>commons-io</artifactId>

   <version>2.4</version>

  </dependency>



  <dependency>



   <groupId>org.springframework</groupId>

   <artifactId>spring-core</artifactId>

   <version>${org.springframework-version}</version>

  </dependency>

  <dependency>

   <groupId>org.springframework</groupId>

   <artifactId>spring-web</artifactId>

   <version>${org.springframework-version}</version>

  </dependency>

  <dependency>

   <groupId>org.springframework</groupId>

   <artifactId>spring-context</artifactId>

   <version>${org.springframework-version}</version>

   <exclusions>

    <!-- Exclude Commons Logging in favor of SLF4j -->

    <exclusion>

     <groupId>commons-logging</groupId>

     <artifactId>commons-logging</artifactId>

    </exclusion>

   </exclusions>

  </dependency>

  <dependency>

   <groupId>org.springframework</groupId>

   <artifactId>spring-webmvc</artifactId>

   <version>${org.springframework-version}</version>

  </dependency>



  <dependency>

   <groupId>javax.servlet</groupId>

   <artifactId>javax.servlet-api</artifactId>

   <version>3.0.1</version>

   <scope>provided</scope>

  </dependency>





 </dependencies>



 <build>

  <finalName>FileUpload</finalName>

 </build>

</project>

Spring configuration file

In this project we are using java based configuration instead of xml based.

You need to configure multipartResolver which will help to accept multi part requests, along with it's implementation (CommonsMultipartResolver). Also you can provide "maxUploadSize" etc.. properties.

package com.test.configuration;

import java.io.IOException;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration 
@ComponentScan("com.test")
@EnableWebMvc
public class Config extends WebMvcConfigurerAdapter {
 @Bean(name="multipartResolver") 
    public CommonsMultipartResolver getResolver() throws IOException{
        CommonsMultipartResolver resolver = new CommonsMultipartResolver();     
        
        //Set the maximum allowed size (in bytes) for each individual file.
        resolver.setMaxUploadSizePerFile(5242880);//5MB     
         
        return resolver;
    }
}

Below file represents the dispatcher servlet configuration:

package com.test.configuration;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration.Dynamic;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;


public class WebInitializer implements WebApplicationInitializer {

 public void onStartup(ServletContext servletContext) throws ServletException {        
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext(); 
        ctx.register(Config.class);  
        ctx.setServletContext(servletContext); 
        Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));  
        servlet.addMapping("/");  
        servlet.setLoadOnStartup(1);  
    }  
}

File Upload RestController

The class is marked up with @RestController annotation , which accept HTTP web-service requests and returns the response.

Simple uploadFile method is written which helps to upload file at destination location, In which you need to pass a MultipartFile as a method parameter e.g. @RequestParam("file") MultipartFile file.

package com.test.controller;

import java.io.File;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

@RestController
public class FileUploadController {

 @RequestMapping(value = "/upload", method = RequestMethod.POST)
 public ResponseEntity uploadFile(@RequestParam("file") MultipartFile file){
  
  String originalFilename = file.getOriginalFilename();
     File destinationFile = new File("C:\\Ankur\\testFiles\\"+originalFilename);
     try {
                 
      file.transferTo(destinationFile);
   System.out.println("File path "+destinationFile.getPath());
   System.out.println("File size "+file.getSize());
  } catch (Exception e) {
   
   e.printStackTrace();
  }
  
  
  return new ResponseEntity(destinationFile.getPath(),HttpStatus.CREATED);
 }
}

Once the file will be uploaded, it will return the file path.

Testing

To verify this Rest API, I am using POSTMAN rest client.

Please follow the below instructions to send a POST request using POSTMAN client.

1. Create .war file and deploy on the tomcat server
2. Choose POST to be the selected HTTP method.
3. Specify the request URL as http://localhost:8081/FileUpload/upload
4. Do not add any header
5. Select form-data radio button under the Body, enter input parameter name as file, select file from drop down and finally select the file to upload.
6. Click on Send Button.
7. Server response with uploaded file path.

Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode) -> [Help 1]

Some time you will be struggling with building the war using maven and will get the error:

Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode) -> [Help 1]

This is because you don't have web.xml in your project and trying to create .war file using maven then you will get this error for sure.

To resolve the issue you need to set the failOnMissingWebXml to false in pom.xml file.

For example:

<properties>
    <failOnMissingWebXml>false</failOnMissingWebXml>  
</properties>

Create .war file. This time you will get success for sure.

Oracle Integration Cloud Service(ICS)

This is my first blog on Oracle Integration Cloud Service(ICS) that would be very useful for all the folks who are interested in learning new Oracle Cloud Service.

In subsequent series of blogs we will walk you through the concepts as well as running demo.

Let's get started with the small concept of ICS.

What is Oracle Integration Cloud Service(ICS) ?

Oracle Integration Cloud Service (ICS) is Oracle’s integration Platform as a Service (iPaaS). It provides a web-based interface to integrate Software as a Service (SaaS) and on-premise applications. It includes various technology and application adapters.

Oracle Integration Cloud Service (ICS) is a simple and powerful integration platform in the cloud to maximize the value of your investments in SaaS and on-premises applications.

Oracle Integration Cloud Service is Oracle's integration platform as a service (iPaas) and includes an intuitive web based integration designer for point and click integration between applications, a rich monitoring dashboard that provides real-time insight into the transactions, all of it running on a mature runtime platform on Oracle Cloud.

ICS will help customers accelerate their integration projects by pre-integrating with several SaaS Applications and will significantly shorten their time-to-market through a highly intuitive user interface and a large library of SaaS Adapters

Advantages of ICS

• Fast
• Enterprise grade
• Simple
• Little knowledge of technologies required

What integration we can do with ICS ?

• Integration of SaaS to SaaS application
• Integration of SaaS to on-premises application
• Integration of on-premises to SaaS application
• Integration of on-premises to on-premises application

Adapters available in ICS

Oracle provides a number of adapters for use with Oracle Integrated Cloud Service. Till ICS version 17.1.3, ICS contains 50 adapters. Below is the full list of available Adapters that can be used to directly integrate your SaaS and on-premises application.

• Adobe eSign
• AQ
• Ariba
• Cocnur
• DB2
• DocuSign
• Eloqa
• Eventbrite
• Evernote
• Facebook
• File
• FTP
• Google Calendar
• Google Mail
• Google Task
• JD Edwards EnterpriseOne
• JMS
• LinkedIn
• Logistics
• MailChimp
• Microsoft Calendar
• Microsoft Contact
• Microsoft Email
• Microsoft SQLServer
• MySQL
• NetSuite
• Oracle Commerce Cloud
• Oracle CPQ
• Oracle Database
• Oracle E-Business Suite
• Oracle ERP Cloud
• Oracle Field Service Cloud
• Oracle HCM Cloud
• Oracle Messaging Cloud Service
• Oracle RightNow
• Oracle Sales Cloud
• Oracle Siebel
• Oracle Utilities
• Responsys
• REST
• Salesforce
• SAP
• ServiceNow
• SOAP
• SRM Cloud Adapter
• Successfactors
• SurveyMonkey
• Trello
• Twilio
• Twitter

For more details about adapters please go through the link

Security capabilities in Integration Cloud Service?

There are several dimensions of security that Integration Cloud Service supports.

• Physical/Data center security - provided by Oracle Cloud Data Centers.
• ICS Product Security – ensuring that your ICS environment is secured from from external threats and also ensure security of any customer's data and metadata within ICS ecosystem.
• ICS capabilities to securely integrate with Oracle's own SaaS apps on OPC seamlessly.
• ICS capabilities to securely integrate with any third party Application (generic SOAP/REST API based interface).
• ICS capabilities to securely integrate with on-premises applications

Related blogs:

Oracle Integration Cloud Service Integrations

Oracle Integration Cloud Service Connections

Oracle Integration Cloud Service Lookups

Oracle Integration Cloud Service Mapping

Oracle Integration Cloud Service Agent

Oracle Integration Cloud Service Agent

Oracle ICS provides an agent framework that enables you to create integrations and exchange messages between on-premises applications and Oracle Integration Cloud Service. Message payloads of up to 5 MB are supported through the use of compression, which may bring the payload down to 512 KB in size. The on-premises agent provides multithreading support, which allows for multiple executors to perform downstream message processing.

This type of integration enables:

• Access SOAP endpoints
• Access non-SOAP endpoints (such as Oracle E-Business Suite and Oracle Siebel)
• Send requests from a cloud application (for example, send a Create Service Order request from an Oracle RightNow Cloud application) to an on-premises E-Business Suite application

The agent framework consists of the following components:

SAAS agent: This agent is installed and runs in Oracle Integration Cloud Service and supports communication with on-premises applications. There is one SAAS agent per Oracle Integration Cloud Service environment.

On-premises agent: This agent is installed and runs in an on-premises environment on the same network as internal systems such as Oracle E-Business Suite, Oracle Database, and others. We download the on-premises agent installer from the Agents page in Oracle Integration Cloud Service to your on-premises environment for installation. There can be multiple host systems, each running one or more agents, in a cloud/on premises topology. The on-premises agent does not permit any explicit inbound connections. All connections are established from the on-premises environment to Oracle Integration Cloud Service.

Once agent is successfully installed and registered with ICS instance the count will get increase to 1.

Oracle Integration Cloud Service Connections

Connection in Oracle ICS

A connection is an instance of an adapter, configured to use a particular endpoint and credentials.

Oracle Integration Cloud Service includes a set of predefined adapters, which are the types of applications on which you can base your connections, such as Oracle Sales Cloud, E-business suite, SOAP, REST, and others.

A connection is based on an adapter. A connection includes the additional information required by the adapter to communicate with a specific instance of an application (this can be referred to as metadata or as connection details).

For example, to create a connection to a Salesforce cloud application instance, you must select the Salesforce adapter and then specify the Enterprise WSDL URL, security policy, and security credentials to connect to it.

Types of Connection

ICS allows you to create three types of connection based on your requirement.

1) Trigger: Trigger is like source. If you want your connection to treat as source of your integration then select Trigger.

2) Invoke: Invoke is like target. If you want your connection to treat as a target in your integration then select Trigger.

3) Trigger and Invoke: Both source and target. If you want your connection to treat as a source as well as target in your integratoin then select Trigger and Invoke.

Oracle Integration Cloud Service Mapping

ICS Mapping

Mapping is the one of key feature in any of the integration where two or more applications are talking to each other.

In most of the cases, the messages we want to transfer between two applications in an integration have different data structures. A visual mapper allows us to map fields applications by dragging source fields onto the target fields.

When we open the mapper for a request or response message in an integration, the data structures are automatically populated with the information pulled from the source and target connections. We can expand and the load data structure levels on demand to display additional levels. There is no limit on the levels of display.

These maps are called transformation maps and use the eXtensible Stylesheet Language(XSL) to describe data mappings which allows us to perform to perform complex data manipulation. A standard set of XPath functions are provided for you to define how data is modified when moving from one application to another.

The mapper supports both qualified and unqualified schemas (that is, schemas without elementFormDefault=”qualified”). Elements and attributes with and without namespace prefixes are also supported.

Elements and attributes for which mapping is required are identified by a blue asterisk (*) to the left of their names. To display only required fields, click the Filter icon, select Required Fields, and click Apply.