Constructor Detail

• public JsonBuilder()

  Instantiates a JSON builder.

• public JsonBuilder(JsonGenerator generator)

  Instantiates a JSON builder with a configured generator.

  Parameters:

  generator - used to generate the output

  Since:

  2.5.0

• public JsonBuilder(Object content)

  Instantiates a JSON builder with some existing data structure.

  Parameters:

  content - a pre-existing data structure

• public JsonBuilder(Object content, JsonGenerator generator)

  Instantiates a JSON builder with some existing data structure and a configured generator.

  Parameters:

  content - a pre-existing data structure

  generator - used to generate the output

  Since:

  2.5.0

Method Detail

• public Object call(Map m)

  Named arguments can be passed to the JSON builder instance to create a root JSON object

  Example:

  
   def json = new groovy.json.JsonBuilder()
   json name: "Guillaume", age: 33
  
   assert json.toString() == '{"name":"Guillaume","age":33}'
   

  Parameters:

  m - a map of key / value pairs

  Returns:

  a map of key / value pairs

• public Object call(List l)

  A list of elements as arguments to the JSON builder creates a root JSON array

  Example:

  
   def json = new groovy.json.JsonBuilder()
   def result = json([1, 2, 3])
  
   assert result instanceof List
   assert json.toString() == "[1,2,3]"
   

  Parameters:

  l - a list of values

  Returns:

  a list of values

• public Object call(Object args)

  Varargs elements as arguments to the JSON builder create a root JSON array

  Example:

  
   def json = new groovy.json.JsonBuilder()
   def result = json 1, 2, 3
  
   assert result instanceof List
   assert json.toString() == "[1,2,3]"
   

  Parameters:

  args - an array of values

  Returns:

  a list of values

• public Object call(Iterable coll, Closure c)

  A collection and closure passed to a JSON builder will create a root JSON array applying the closure to each object in the collection

  Example:

  
   class Author {
        String name
   }
   def authors = [new Author (name: "Guillaume"), new Author (name: "Jochen"), new Author (name: "Paul")]
  
   def json = new groovy.json.JsonBuilder()
   json authors, { Author author ->
        name author.name
   }
  
   assert json.toString() == '[{"name":"Guillaume"},{"name":"Jochen"},{"name":"Paul"}]'
   

  Parameters:

  coll - a collection

  c - a closure used to convert the objects of coll

  Returns:

  a list of values

• public Object call(Collection coll, Closure c)

  Delegates to call(Iterable, Closure)

• public Object call(Closure c)

  A closure passed to a JSON builder will create a root JSON object

  Example:

  
   def json = new groovy.json.JsonBuilder()
   def result = json {
        name "Guillaume"
        age 33
   }
  
   assert result instanceof Map
   assert json.toString() == '{"name":"Guillaume","age":33}'
   

  Parameters:

  c - a closure whose method call statements represent key / values of a JSON object

  Returns:

  a map of key / value pairs

• public Object getContent()

• @Override public Object invokeMethod(String name, Object args)

  A method call on the JSON builder instance will create a root object with only one key whose name is the name of the method being called. This method takes as arguments:

  • a closure
  • a map (ie. named arguments)
  • a map and a closure
  • or no argument at all

  Example with a classical builder-style:

  
   def json = new groovy.json.JsonBuilder()
   def result = json.person {
        name "Guillaume"
        age 33
   }
  
   assert result instanceof Map
   assert json.toString() == '{"person":{"name":"Guillaume","age":33}}'
   

  Or alternatively with a method call taking named arguments:

  
   def json = new groovy.json.JsonBuilder()
   json.person name: "Guillaume", age: 33
  
   assert json.toString() == '{"person":{"name":"Guillaume","age":33}}'
   

  If you use named arguments and a closure as last argument, the key/value pairs of the map (as named arguments) and the key/value pairs represented in the closure will be merged together — the closure properties overriding the map key/values in case the same key is used.

  
   def json = new groovy.json.JsonBuilder()
   json.person(name: "Guillaume", age: 33) { town "Paris" }
  
   assert json.toString() == '{"person":{"name":"Guillaume","age":33,"town":"Paris"}}'
   

  The empty args call will create a key whose value will be an empty JSON object:

  
   def json = new groovy.json.JsonBuilder()
   json.person()
  
   assert json.toString() == '{"person":{}}'
   

  Parameters:

  name - the single key

  args - the value associated with the key

  Returns:

  a map with a single key

• public String toPrettyString()

  Pretty-prints and formats the JSON payload.

  This method calls the JsonLexer to parser the output of the builder, so this may not be an optimal method to call, and should be used mainly for debugging purpose for a human-readable output of the JSON content.

  Returns:

  a pretty printed JSON output

• @Override public String toString()

  Serializes the internal data structure built with the builder to a conformant JSON payload string

  Example:

  
   def json = new groovy.json.JsonBuilder()
   json { temperature 37 }
  
   assert json.toString() == '{"temperature":37}'
   

  Returns:

  a JSON output

• @Override public Writer writeTo(Writer out)

  The JSON builder implements the Writable interface, so that you can have the builder serialize itself the JSON payload to a writer.

  Example:

  
   def json = new groovy.json.JsonBuilder()
   json { temperature 37 }
  
   def out = new StringWriter()
   out << json
  
   assert out.toString() == '{"temperature":37}'
   

  Parameters:

  out - a writer on which to serialize the JSON payload

  Returns:

  the writer