FreeMarker (FTL) Hello World Tutorial with Example

In our previous tutorial Introduction to FreeMarker Template, we saw basics and overview of FTL. Also some of its features and comparison with other view technologies such as Velocity and JSP.

Following is the list of tutorials from Freemarker tutorial series.

Today we will create our first Hello World FreeMarker application. To start with our app will be very basic. We define one ftl template and load it in Java using freemarker api. In Java, we create data and pass it to freemarker to render the output. So all in all we get output as a text file as well as on standard output (console). So lets get started.

Things We Need

Before getting started, I would like to highlight tools and technologies used in this project.

We’ll need:

  1. JDK 1.5 or above (download)
  2. Eclipse IDE 3.2.x or above (download)
  3. Freemarker 2.2.8 or above (download)

Ok, we have all what we need. So lets get started.

Hello World FreeMaker

In eclipse create a Java project. Go to File > New > Project… > Java Project. Enter project name as Freemarker_Hello_World and click Finish.

The basic Java Project is created. Now we create a freemarker template file (.ftl) as our base template. We will use this in our hello world example. Create a file helloworld.ftl under src folder. Following is the content:

File: src/helloworld.ftl

FreeMarker Template example: ${message}  

=======================
===  County List   ====
=======================
<#list countries as country>
	${country_index + 1}. ${country}
</#list>

Now create FTLHelloWorld.java class inside source folder. I have created a package net.viralpatel.freemarker and create this class inside it.

File: src/net/viralpatel/freemarker/FTLHelloWorld.java

package net.viralpatel.freemarker;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;

public class FTLHelloWorld {
	
	public static void main(String[] args) {
		
		//Freemarker configuration object
		Configuration cfg = new Configuration();
		try {
			//Load template from source folder
			Template template = cfg.getTemplate("src/helloworld.ftl");
			
			// Build the data-model
			Map<String, Object> data = new HashMap<String, Object>();
			data.put("message", "Hello World!");

			//List parsing 
			List<String> countries = new ArrayList<String>();
			countries.add("India");
			countries.add("United States");
			countries.add("Germany");
			countries.add("France");
			
			data.put("countries", countries);

			
			// Console output
			Writer out = new OutputStreamWriter(System.out);
			template.process(data, out);
			out.flush();

			// File output
			Writer file = new FileWriter (new File("C:\\FTL_helloworld.txt"));
			template.process(data, file);
			file.flush();
			file.close();
			
		} catch (IOException e) {
			e.printStackTrace();
		} catch (TemplateException e) {
			e.printStackTrace();
		}
	}
}

You might get error in Eclipse because of the classpath issue. Add freemarker.jar in lib folder (create a lib folder if it doesn’t exists). Once you have added freemarker.jar and included in your classpath, the error should go.

Below is the project structure once we add all source code files.

freemarker-hello-world-java-project-structure

Execute the FTLHelloWorld.java class (eclipse shortcut Alt+Shift X, J). Following output will be generated in Console.

FreeMarker Template example: Hello World!

========================
===   Country List =====
========================
	1. India
	2. United States
	3. Germany
	4. France

Also a file will be generated C:\FTL_helloworld.txt with the same output.
ftl-hello-world-java-file-output

Thus note how we passed data from Java to FTL and the same get painted. The ${message} got replaced with the message that we populated in Java. Also notice how we passed a country List<String> through Java and inside FTL we used <#list> </#list> to display its values.

Download Source Code

FreeMarker_helloworld.zip (507 KB)



25 Comments

  • Lars Vogel 7 November, 2012, 23:02

    Thanks, that got me started. Now I can replace my own template engine with FreeMaker.

    • Viral Patel 8 November, 2012, 0:07

      Ohhhh god.. Lars Vogel’s comment on my blog!! Feels awesomee :) Am glad it helped.

  • Nishant Kanungo 16 November, 2012, 11:50

    I am getting the following exception.

    Exception in thread “main” java.lang.NoClassDefFoundError: com/google/common/collect/MapMaker
    at freemarker.core.Environment.(Environment.java:93)
    at freemarker.template.Template.createProcessingEnvironment(Template.java:367)
    at freemarker.template.Template.process(Template.java:237)
    at com.infy.freemaker.FTLHelloWorld.main(FTLHelloWorld.java:28)

    Please help me out.

  • Nishant Kanungo 16 November, 2012, 12:16

    We need to add google-collections-1.0-rc2.jar along with the freemaker.jar in the build path.

  • Sharath 16 November, 2012, 16:35

    Hi Viral Patel,
    Can you show me how to use StringTemplateLoader?
    I have 3 to 4 values which i need to put it in Map in the same string

  • Lars Vogel 19 November, 2012, 15:04

    @Viral: :-)

  • bharat thakarar 12 December, 2012, 10:18

    it helped a lot…
    thanx

  • Nurs 18 December, 2012, 19:22

    I have problem like this java.io.FileNotFoundException: Template src/main/java/helloworld.ftl not found.
    at freemarker.template.Configuration.getTemplate(Configuration.java:580)
    at freemarker.template.Configuration.getTemplate(Configuration.java:543)

    Can you help me?
    Thanks

  • unnati 19 December, 2012, 12:43

    Very easy to understand. thanks

  • nabil 16 January, 2013, 16:08

    Hi,
    it would be preferable to add “throws IOException, TemplateException”

    exemple:

    public static void main(String[] args) throws IOException, TemplateException
    {
    }

    thank you

  • Deepesh 17 January, 2013, 18:38

    Could anybody tell me how to send the ftl contents in the email body. I have a requirement where user submits the timesheets and then his Manager should get an email. I have done this with Reading the generated ftl file but want to avoid this reading step and send direct ftl content in email.

    Appreciate your help !

    Thanks …

  • Hung 19 January, 2013, 9:55

    Hi Deepesh,
    Not sure I get your point. But probably, you can do like something like below:

    public static void main(String[] args) {
    		String templateStr="Hello ${name}";
    		 try {
    		 	Template t = new Template("whateverTemplateName", new StringReader(templateStr),
    				 new Configuration());
    			Map data = new HashMap();
    			data.put("name", "John");
    			Writer out = new OutputStreamWriter(System.out);
    			t.process(data, out);
    			out.flush();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    

    You also may want to read more in javadoc of StringTemplateLoader

  • Fatman13 2 April, 2013, 1:23

    Does country_index just get init to 0 by default?

    • xp 15 July, 2013, 12:40

      I think so.

  • Karthi 6 June, 2013, 16:40

    Very clear.

    Thanks a lot.

  • chandni jain 8 November, 2013, 17:20

    Viral Can You explain step by step process to generate pdf report using xslt-fo

  • Zeeshan Akhter 6 January, 2014, 22:14

    that’s great effort and its quick start up guide…………

  • Asha 8 January, 2014, 6:28

    very nice!

  • sujata 12 February, 2014, 14:34

    shouldn’t the TemplateLoader be set in Configuration, otherwise it give FileNotFoundException.

  • Amel 14 February, 2014, 19:46

    I develop an application to generate files using freemarker engine. In some case, if there is an exception, even if I catch it, freemarker generate a file that contains this exception. How can I avoid the generation of the file in that case?
    Can some one help me?

  • Aldo 25 March, 2014, 15:49

    Thanks. It worked. I like Freemarker a lot.

  • Yen 16 April, 2014, 3:24

    I can’t get it to output the file in C: drive.
    I am using Eclipse/SuiteCloude IDE

  • Mahesh A 16 April, 2014, 15:48

    thanx. this is very easy. can you please provide more examples?

  • ESSEST 25 April, 2014, 7:03

    this is the first time I use freemarker, so i have a question, i have a tree so there is a parent and a children and also the children have there own children, so can i use this code to extract parent and there children.

    ${key.name}

    ${key1.name}

    ${key2.name}

    • ESSEST 25 April, 2014, 7:03
       
      <#list List-1 as key> 
          <div> ${key.name} </div>
       
          <#list ${key.children} as key1> 
          <div> ${key1.name} </div>
                <#list ${key1}.children as key2>
                 <div> ${key2.name} </div> 
                </#list>
          </#list>
      </#list>
      

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