com.hazelcast.jet.json

Class JsonUtil

java.lang.Object

com.hazelcast.jet.json.JsonUtil

public final class JsonUtil
extends Object

Util class to parse JSON formatted input to various object types or convert objects to JSON strings.

We use the lightweight JSON library `jackson-jr` to parse the given input or to convert the given objects to JSON string. If `jackson-annotations` library present on the classpath, we register JacksonAnnotationExtension to so that the JSON conversion can make use of Jackson Annotations.

Since:

Jet 4.2

Method Summary

Modifier and Type	Method and Description
static Object	anyFrom(String jsonString) Converts a JSON string to an Object.
static <T> T	beanFrom(String jsonString, Class<T> type) Converts a JSON string to an object of the given type.
static <T> Stream<T>	beanSequenceFrom(Path path, Class<T> type) Parses the file and returns a stream of objects with the given type.
static <T> Iterator<T>	beanSequenceFrom(Reader reader, Class<T> type) Returns an Iterator over the sequence of JSON objects parsed from given reader.
static HazelcastJsonValue	hazelcastJsonValue(Object object) Creates a HazelcastJsonValue by converting given the object to string using Object.toString().
static List<Object>	listFrom(String jsonString) Converts a JSON string to a List.
static <T> List<T>	listFrom(String jsonString, Class<T> type) Converts a JSON string to a List of given type.
static Map<String,Object>	mapFrom(Object object) Converts a JSON string to a Map.
static Stream<Map<String,Object>>	mapSequenceFrom(Path path) Parses the file and returns a stream of Map.
static Iterator<Map<String,Object>>	mapSequenceFrom(Reader reader) Returns an Iterator over the sequence of JSON objects parsed from given reader.
static String	toJson(Object object) Creates a JSON string for the given object.

Methods inherited from class java.lang.Object

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

Method Detail

hazelcastJsonValue

@Nonnull
public static HazelcastJsonValue hazelcastJsonValue(@Nonnull
                                                             Object object)

Creates a HazelcastJsonValue by converting given the object to string using Object.toString().

beanFrom

@Nullable
public static <T> T beanFrom(@Nonnull
                                       String jsonString,
                                       @Nonnull
                                       Class<T> type)
                                throws IOException

Converts a JSON string to an object of the given type.

Throws:

IOException

mapFrom

@Nullable
public static Map<String,Object> mapFrom(@Nonnull
                                                   Object object)
                                            throws IOException

Converts a JSON string to a Map.

Throws:

IOException

listFrom

@Nullable
public static <T> List<T> listFrom(@Nonnull
                                             String jsonString,
                                             @Nonnull
                                             Class<T> type)
                                      throws IOException

Converts a JSON string to a List of given type.

Throws:

IOException

listFrom

@Nullable
public static List<Object> listFrom(@Nonnull
                                              String jsonString)
                                       throws IOException

Converts a JSON string to a List.

Throws:

IOException

anyFrom

@Nullable
public static Object anyFrom(@Nonnull
                                       String jsonString)
                                throws IOException

Converts a JSON string to an Object. The returned object will differ according to the content of the string:

• content is a JSON object, returns a Map. See mapFrom(Object).
• content is a JSON array, returns a List. See listFrom(String).
• content is a String, null or primitive, returns String, null or primitive.

Throws:

IOException

beanSequenceFrom

@Nonnull
public static <T> Iterator<T> beanSequenceFrom(@Nonnull
                                                        Reader reader,
                                                        @Nonnull
                                                        Class<T> type)
                                                 throws IOException

Returns an Iterator over the sequence of JSON objects parsed from given reader. Each object is converted to the given type.

Throws:

IOException

mapSequenceFrom

@Nonnull
public static Iterator<Map<String,Object>> mapSequenceFrom(@Nonnull
                                                                    Reader reader)
                                                             throws IOException

Returns an Iterator over the sequence of JSON objects parsed from given reader. Each object is converted to a Map. It will throw ClassCastException if JSON objects are just primitives (String, Number, Boolean) or JSON arrays (List).

Throws:

IOException

beanSequenceFrom

@Nonnull
public static <T> Stream<T> beanSequenceFrom(Path path,
                                                      @Nonnull
                                                      Class<T> type)
                                               throws IOException

Parses the file and returns a stream of objects with the given type. The file is considered to have a streaming JSON content, where each JSON string is separated by a new-line. The JSON string itself can span on multiple lines.

See Sources.json(String, Class).

Throws:

IOException

mapSequenceFrom

@Nonnull
public static Stream<Map<String,Object>> mapSequenceFrom(Path path)
                                                           throws IOException

Parses the file and returns a stream of Map. The file is considered to have a streaming JSON content, where each JSON string is separated by a new-line. The JSON string itself can span on multiple lines.

See Sources.json(String, Class).

Throws:

IOException

toJson

@Nonnull
public static String toJson(@Nonnull
                                     Object object)
                              throws IOException

Creates a JSON string for the given object.

Throws:

IOException