Velocity Quick Start [5]-using object attributes and methods in templates

Source File FiveExample. java

package nc.jonathan.velocity;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;

/**
* <P>
* Fifth learning instance
* </P>
*
* <P> the passed parameter is an object, and the object operation in the template </P>
*
* Create on 2006-4-3 14:43:17
*
* @ Author Jonathan Q. Bo
* @ Version 1.0 valocity Study
*/

Public class fiveexample {
 
/**
* Test Method
*/
Public void test (){
Try {
/* Initialize the runtime engine and specify the template folder location for initialization */
Properties P = new properties ();
P. setproperty ("file. Resource. loader. Path", "VM ");
Velocity. INIT (P );

/* Create the context and put the data */
VelocityContext context = new VelocityContext ();
Context. put ("exampleObject", new ExampleObject ());

/* Output target of parsed data, subclass of java. io. Writer */
FileWriter w = new FileWriter ("gen/systthexamplegen. java ");
BufferedWriter bw = new BufferedWriter (w );


/* Parse */
// Velocity. mergeTemplate ("secondtemplate. vm", context, w );
Velocity. mergeTemplate ("effecthtemplate. vm", "gb2312", context, bw );

Bw. flush ();
Bw. close ();
System. Out. println ("#... successful! ");
} Catch (resourcenotfoundexception E1 ){
System. Out. println ("# The source file does not exist! ");
E1.printstacktrace ();
} Catch (parseerrorexception E2 ){
System. Out. println ("# file parsing error! ");
E2.printstacktrace ();
} Catch (methodinvocationexception E3 ){
System. Out. println ("# method call exception! ");
E3.printstacktrace ();
} Catch (exception E4 ){
System. Out. println ("# other errors! ");
E4.printstacktrace ();
}
}

 public static void main(String[] args) {
  FiveExample example = new FiveExample();
  example.test();
 }
}

Source File ExampleObject. java

package nc.jonathan.velocity;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
* <P>
* Objects used in the template
* </P>
*
* Create on 2006-4-3 18:55:33
*
* @ Author Jonathan Q. Bo
* @ Version 1.0 valocity study
*/

public class ExampleObject{ 
 private String name;
 private List friends;
 
 public ExampleObject(){
  this.name = "jonathan";
  friends = new ArrayList();
  for(int i = 0; i < 8; i++){
   friends.add(" friend" + i);   
  }
 }
 
 public String getAllFriends(){
  String all = name + "'s friends : ";
  for(Iterator itt = friends.iterator(); itt.hasNext(); ){
   all += "," + (String)itt.next();
  }
  return all;
 }
 
 public String rename(String newName){
  this.setName(newName);
  return newName;
 }
 
 public String getNewName(){
  String[] names = {"Jacy","Tom","Cat","Random"};
  int random  = (int)(Math.random()*10%3);
  return names[random];
 }
 
 public List getFriends() {
  return friends;
 }
 public void setFriends(List friends) {
  this.friends = friends;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
}

Template File

/**********************************/

test object property : ${exampleObject.name}

test object property : $exampleObject.name

test object property: $exampleObject.getName()

/***********************************/

test object method : ${exampleObject.getAllFriends()}

test object method : $exampleObject.getAllFriends()

/***********************************/

test object method : $exampleObject.rename($exampleObject.getNewName())

Output file

/**********************************/

test object property : jonathan

test object property : jonathan

test object property: jonathan

/***********************************/

test object method : jonathan's friends : , friend0, friend1, friend2, friend3, friend4, friend5, friend6, friend7

test object method : jonathan's friends : , friend0, friend1, friend2, friend3, friend4, friend5, friend6, friend7

/***********************************/

test object method : Jacy