JarCastingStringTailor
A Java string generation library for building complex statements.
Is not StringBuilder or String.format enough?
I was writing a lot of code that had to deal with building complex string statements. A problem I encountered while doing so is that the methods started to get out of control in both size and number. At that point, I decided that there was probably a need for a string utility that reduced the complexity of creating statements with optional clauses and lists of variables.
StringBuilder and String.format are both great utilities, but this library is a higher level abstraction that allows statements to be built quickly and more understandably.
Installation
StringTailor will be in maven central. Simply add the following dependency:
<dependency>
<groupId>com.siirush</groupId>
<artifactId>stringtailor</artifactId>
<version>0.1.3</version>
</dependency>
Changelog
0.1.0 - Initial release.
0.1.1 - Change GitHub repository URL.
0.1.2 - Fix issue with optional clauses and empty lists. Add test case for optional clause with an empty list.
0.1.3 - Add multi support for building Strings through multiplication. Add better error messaging for failed evaluations.
0.1.4 - Add support for passing a required expression in statement() and initial values in context().
Usage
Great usage examples can be found in the test cases. I included a couple of those in text here for reference. It is important to note that statically including StringTailorDsl's methods is required in order to write code like the following.
Simple usage:
EvaluatableStatement statement =
statement()
.add(literal("Hello, "),var("SUBJECT"),literal("!"))
.done();
Map<String,Object> context =
context()
.add("SUBJECT","World")
.done();
assertEquals("Hello, World!",evaluator.evaluate(statement, context));
Required expression in first usage:
EvaluatableStatement statement =
statement(literal("Hello, "),var("SUBJECT"),literal("!")).done();
Map<String,Object> context =
context("SUBJECT","World")
.done();
assertEquals("Hello, World!",evaluator.evaluate(statement, context));
Context values in first usage:
EvaluatableStatement statement =
statement(literal("Grocery list: "),list("GROCERY LIST"))
.done();
Map<String,Object> context =
context("GROCERY LIST","Milk","Eggs","Bread")
.done();
assertEquals("Grocery list: Milk,Eggs,Bread",evaluator.evaluate(statement, context));
With an optional expression:
EvaluatableStatement statement =
statement()
.add(literal("Hello"))
.optional(literal(", "),var("SUBJECT"))
.add(literal("!"))
.done();
Map<String,Object> context =
context()
.add("SUBJECT", "World")
.done();
Map<String,Object> emptyContext =
context()
.done();
assertEquals("Hello, World!",evaluator.evaluate(statement, context));
assertEquals("Hello!",evaluator.evaluate(statement, emptyContext));
With a list:
List<String> groceryList = new ArrayList<String>();
groceryList.add("Milk");
groceryList.add("Eggs");
groceryList.add("Bread");
EvaluatableStatement statement =
statement()
.add(literal("Grocery list: "),list("GROCERY LIST"))
.done();
Map<String,Object> context =
context()
.add("GROCERY LIST","Milk","Eggs","Bread")
.done();
Map<String,Object> contextWithList =
context()
.add("GROCERY LIST",groceryList)
.done();
assertEquals("Grocery list: Milk,Eggs,Bread",evaluator.evaluate(statement, context));
assertEquals("Grocery list: Milk,Eggs,Bread",evaluator.evaluate(statement, contextWithList));
With multi clauses:
EvaluatableStatement statement =
statement()
.add(multi("STARS","*"))
.done();
Map<String,Object> context =
context()
.add("STARS",8)
.done();
assertEquals("********",evaluator.evaluate(statement, context));
EvaluatableStatement statement =
statement()
.add(multi("STARS","*",multiConfig(",")))
.done();
Map<String,Object> context =
context()
.add("STARS",8)
.done();
assertEquals("*,*,*,*,*,*,*,*",evaluator.evaluate(statement, context));
EvaluatableStatement statement =
statement()
.add(multi("STARS","*",multiConfig("(",",",")")))
.done();
Map<String,Object> context =
context()
.add("STARS",8)
.done();
assertEquals("(*,*,*,*,*,*,*,*)",evaluator.evaluate(statement, context));
EvaluatableStatement statement =
statement()
.optional(multi("STARS","*",multiConfig(",")))
.done();
Map<String,Object> emptyContext =
context()
.done();
assertEquals("",evaluator.evaluate(statement, emptyContext));