String Replacement in Java, Similar to a Velocity Template

String replacement in java, similar to a velocity template

Use StringSubstitutor from Apache Commons Text.

Dependency import

Import the Apache commons text dependency using maven as bellow:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-text</artifactId>
    <version>1.10.0</version>
</dependency>

Example

Map<String, String> valuesMap = new HashMap<String, String>();
valuesMap.put("animal", "quick brown fox");
valuesMap.put("target", "lazy dog");
String templateString = "The ${animal} jumped over the ${target}.";
StringSubstitutor sub = new StringSubstitutor(valuesMap);
String resolvedString = sub.replace(templateString);

Replace only part of a string with velocity

The $test.something is causing the problem.

It is expecting a variable something inside the object test.

Use ${test}.something instead...

--Cheers, Jay

How to replace a query string in an Apache Velocity template?

I managed to fix the issue myself - it turned out that there was another file (which gets called on every page) in which the $!request.getParameter('freeText')" variable is used. I have updated that file so that it uses the new $!replacedQueryString variable (ie the one with the JavaScript stripped out) instead of the existing "$!request.getParameter('freeText')" variable. This now prevents the JavaScript from being executed on every page.

So, this is the final working code in the header Velocity file:

    #set($freeTextParameter = "$!m.request.httpRequest.getParameter('freeText')")
#if($freeTextParameter)
    #set($replacedQueryString = "$freeTextParameter.replace('confirm','').replace('<','').replace('>','').replace('(','').replace(')','').replace(';','').replace('/','').replace('\"','').replace('&','').replace('+','').replace('script','').replace('prompt','').replace('*','').replace('.','')")
#end

String replacement in java, similar to a velocity template

Use StringSubstitutor from Apache Commons Text.

Dependency import

Import the Apache commons text dependency using maven as bellow:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-text</artifactId>
    <version>1.10.0</version>
</dependency>

Example

Map<String, String> valuesMap = new HashMap<String, String>();
valuesMap.put("animal", "quick brown fox");
valuesMap.put("target", "lazy dog");
String templateString = "The ${animal} jumped over the ${target}.";
StringSubstitutor sub = new StringSubstitutor(valuesMap);
String resolvedString = sub.replace(templateString);

How to replace a set of tokens in a Java String?

The most efficient way would be using a matcher to continually find the expressions and replace them, then append the text to a string builder:

Pattern pattern = Pattern.compile("\\[(.+?)\\]");
Matcher matcher = pattern.matcher(text);
HashMap<String,String> replacements = new HashMap<String,String>();
//populate the replacements map ...
StringBuilder builder = new StringBuilder();
int i = 0;
while (matcher.find()) {
    String replacement = replacements.get(matcher.group(1));
    builder.append(text.substring(i, matcher.start()));
    if (replacement == null)
        builder.append(matcher.group(0));
    else
        builder.append(replacement);
    i = matcher.end();
}
builder.append(text.substring(i, text.length()));
return builder.toString();

Python string 'Template' equivalent in java

String s = String.format("%s likes %s", "tim", "kung pao");

or

System.out.printf("%s likes %s", "tim", "kung pao");

you can easily do the templating with this too.

String s = "%s likes %s";
String.format(s, "tim", "kung pao");

---

Related Topics