jlibs.core.util.regex

Class TemplateMatcher

java.lang.Object

jlibs.core.util.regex.TemplateMatcher

public class TemplateMatcher
extends Object

TemplateMatcher is a simple template engine provided with jlibs.

 import jlibs.core.util.regex.TemplateMatcher;

 String msg = "Hai ${user}, your mail to ${email} has been sent successfully.";

 TemplateMatcher matcher = new TemplateMatcher("${", "}");

 Map vars = new HashMap();
 vars.put("user", "santhosh");
 vars.put("email", "scott@gmail.com");
 System.out.println(matcher.replace(msg, vars));
 

prints following:

 Hai santhosh, your mail to scott@gmail.com has been sent successfully.
 

The two arguments to TemplateMatcher are leftBrace and rightBrace.
For example:

 String msg = "Hai ___user___, your mail to ___email___ has been sent successfully.";
 TemplateMatcher matcher = new TemplateMatcher("___", "___");

 Map vars = new HashMap();
 vars.put("user", "santhosh");
 vars.put("email", "scott@gmail.com");
 System.out.println(matcher.replace(msg, vars));
 

also prints the same output.

NOTE: if a variables resolves to null, then it appears as it is in result string

Right Brace is optional. in such case use new TemplateMatcher(leftBrace):

 String msg = "Hai $user, your mail to $email has been sent successfully.";

 TemplateMatcher matcher = new TemplateMatcher("$");

 Map vars = new HashMap();
 vars.put("user", "santhosh");
 vars.put("email", "scott@gmail.com");
 System.out.println(matcher.replace(msg, vars));
 

also prints the same output;

Variable Resolution:

you can also resolve variables dynamically:

 String msg = "Hai ${user.name}, you are using JVM from ${java.vendor}.";

 TemplateMatcher matcher = new TemplateMatcher("${", "}");
 String result = matcher.replace(msg, new TemplateMatcher.VariableResolver(){
     @Override
     public String resolve(String variable){
         return System.getProperty(variable);
     }
 });
 

prints

 Hai santhosh, you are using JVM from Apple Inc..
 

VariableResolver interface contains single method:

 public String resolve(String variable)
 

Using with writers:

Let us say you have file template.txt which contains:

 Hai ${user},
     your mail to ${email} has been sent successfully.
 

running the following code:

 TemplateMatcher matcher = new TemplateMatcher("${", "}");

 Map vars = new HashMap();
 vars.put("user", "santhosh");
 vars.put("email", "scott@gmail.com");
 matcher.replace(new FileReader("templte.txt"), new FileWriter("result.txt"), vars);
 

will creates file result.txt with following content:

 Hai santhosh,
     your mail to scott@gmail.com has been sent successfully.
 

Copying Files/Directories:

TemplateMatcher provides method to copy files/directories:

 public void copyInto(File source, File targetDir, Map variables) throws IOException;
 

Name of each file and directory is treated as a template.
If name of directory is ${xyz} after applying template, if resolves to "a/b/c",
then it expands into the directory structure a/b/c; for example we have following directory structure:

 ${root}
   |- ${class}.java
 

and content of ${class}.java file is:

 package ${rootpackage};

 public class ${class} extends Comparator{

 }
 

now running following code:

 TemplateMatcher matcher = new TemplateMatcher("${", "}");

 Map vars = new HashMap();
 vars.put("root", "org/example");
 vars.put("rootpackage", "org.example");
 vars.put("class", "MyClass");

 matcher.copyInto(new File("${root}"), new File("."), vars);
 

creates:

 org
   |-example
     |-MyClass.java
 

and content of MyClass.java will be:

 package org.example;

 public class MyClass extends Comparator{

 }
 

Author:

Santhosh Kumar T

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TemplateMatcher.MapVariableResolver
static interface	TemplateMatcher.VariableResolver

Constructor Summary

Constructors

Constructor and Description
TemplateMatcher(String prefix)
TemplateMatcher(String leftBrace, String rightBrace)

Method Summary

Modifier and Type	Method and Description
void	copyInto(File source, File targetDir, Map<String,String> variables)
void	copyInto(File source, File targetDir, TemplateMatcher.VariableResolver resolver)
static void	main(String[] args)
String	replace(CharSequence input, TemplateMatcher.VariableResolver resolver)
void	replace(Reader reader, Writer writer, Map<String,String> variables)
void	replace(Reader reader, Writer writer, TemplateMatcher.VariableResolver resolver)
String	replace(String input, Map<String,String> variables)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TemplateMatcher

public TemplateMatcher(String leftBrace,
                       String rightBrace)

TemplateMatcher

public TemplateMatcher(String prefix)

Method Detail

replace

public String replace(CharSequence input,
                      TemplateMatcher.VariableResolver resolver)

replace

public String replace(String input,
                      Map<String,String> variables)

replace

public void replace(Reader reader,
                    Writer writer,
                    TemplateMatcher.VariableResolver resolver)
             throws IOException

Throws:

IOException

replace

public void replace(Reader reader,
                    Writer writer,
                    Map<String,String> variables)
             throws IOException

Throws:

IOException

copyInto

public void copyInto(File source,
                     File targetDir,
                     TemplateMatcher.VariableResolver resolver)
              throws IOException

Throws:

IOException

copyInto

public void copyInto(File source,
                     File targetDir,
                     Map<String,String> variables)
              throws IOException

Throws:

IOException

main

public static void main(String[] args)