FreeMarker using javax.json.JsonObject as Data Model - freemarker

Question

I am testing FreeMarker
Maven dependencies:
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>javax.json</artifactId>
<version>1.0.4</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.freemarker</groupId>
<artifactId>freemarker</artifactId>
<version>2.3.23</version>
</dependency>
</dependencies>
Simple class User:
public class User {
private String firstName;
private String lastName;
private String email;
public User(String firstName, String lastName, String email) {
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
Simple FreeMarker file (basicJson.ftl):
Name: ${user.firstName} ${user.lastName}
Class for create a Configuration:
import java.io.File;
import java.io.IOException;
import freemarker.template.Configuration;
import freemarker.template.TemplateExceptionHandler;
public class FreemarkerConfigurationFactory {
public static Configuration newFreemarkerConfiguration() throws IOException {
Configuration cfg = new Configuration(Configuration.VERSION_2_3_23);
cfg.setDirectoryForTemplateLoading(new File("./templates/tests/"));
cfg.setDefaultEncoding("UTF-8");
cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
cfg.setLogTemplateExceptions(false);
return cfg;
}
}
Test class:
import static org.junit.Assert.assertEquals;
import java.io.ByteArrayOutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
import javax.json.Json;
import javax.json.JsonObject;
import org.junit.Before;
import org.junit.Test;
import freemarker.template.Configuration;
import freemarker.template.Template;
public class FreemarkerJsonTest {
private Configuration cfg;
private ByteArrayOutputStream output;
private Template template;
private Writer writer;
private Map<String, Object> map;
#Before
public void setUp() throws Exception {
cfg = FreemarkerConfigurationFactory.newFreemarkerConfiguration();
output = new ByteArrayOutputStream();
writer = new OutputStreamWriter(output);
map = new HashMap<>();
}
#Test
public void objectTest() throws Exception {
User user = new User("Clarice", "Leman", "clarice.leman#domain.com");
map.put("user", user);
String outputString = process("basicJson.ftl", map);
assertEquals("Name: Clarice Leman", outputString);
}
#Test
public void jsonTest() throws Exception {
JsonObject jsonUser = Json.createObjectBuilder()
.add("id", 10)
.add("firstName", "Clarice")
.add("lastName", "Leman")
.add("email", "clarice.leman#domain.com")
.build();
map.put("user", jsonUser);
String outputString = process("basicJson.ftl", map);
assertEquals("Name: Clarice Leman", outputString);
}
private String process(String templateName, Object root) throws Exception {
template = cfg.getTemplate(templateName);
template.process(root, writer);
return output.toString();
}
}
The question is that the test "objectTest()" passes but the test "jsonTest()" no, because it produces a String:
Name: "Clarice" "Leman"
Using a Online FreeMarker Template (http://freemarker-online.kenshoo.com/):
Template:
Name: ${user.firstName} ${user.lastName}
Data Model:
user = {"firstName":"Clarice","lastName":"Leman","email":"clarice.leman#domain.com"}
Result
Name: Clarice Leman

Answer 1

The JSON you enter on FreeMarker Online is transformed to List-s and Map-s by FreeMarker Online before passed to FreeMarker itself. The syntax of that whole box is specific to that online service. So if you have JSON to show, either it has to be converted to a something that the default ObjectWrapper of FreeMarker already understands, or the ObjectWrapper has to be extended to understand javax.json classes. (But often, you bind the JSON to some application-specific classes anyway, and those often already use JavaBeans conventions and List-s, which the default ObjectWrapper understands.)