Highly inspired and copied from @mandubian (Pascal Voitot) Json lib for Play 2 Scala
Will be the standard Json library for the ReactiveCouchbase Java wrapper
Every json structure is represented with a Json AST.
In that AST, everything is a JsValue.
Then each json type inherit from it :
JsNumber, JsString, JsBoolean, JsObject, JsArray, JsUndefined, JsNull
The Json class provides the basic functions to create/manipulate json AST. Json also provides
methods like Json.stringify, Json.prettyPrint and Json.parse to manipulate Json structures from and to strings.
The JsValue::as() method allows you to cast AST elements to specific JsValue subtypes or corresponding Java types.
You can also provide Reader and Writer to provide custom serialization/deserialization for you json ASTs. You can also
use it to validate, transform or enhance json ASTs.
JsObject o = Json.obj(
$( "key1", "value1" ),
$( "key2", "value2" ),
$( "key3", 1 ),
$( "key4", 2.3 ),
$( "key5", Json.obj(
$( "key1", "value1" ),
$( "key2", "value2" ),
$( "key3", Json.arr(
"val1", "val2", 3, Json.obj(
$( "key1", "value1" )
)
))
))
);
JsObject user = Json.toJson(new User(...));JsObject o = Json.obj(
$( "key1", "value1" ),
$( "key2", "value2" )
);
String json = Json.stringify( o ); // {"key1":"value1", "key2":"value2"}String prettyJson = Json.prettyPrint( o ); // {
// "key1":"value1",
// "key2":"value2"
// }JsValue jsVal = Json.parse( "{\"key1\":\"val1\"}" );
JsObject o = jsVal.as(JsObject.class);JsObject jsObj = jsVal.as(JsObject.class);
for (JsObject obj : jsVal.asOpt(JsObject.class)) {
JsObject newObj = obj.add(Json.obj( $( "key1", "value1" )));
JsObject other = Json.obj(
$( "key1", "value1" ),
$( "key2", "value2" )
);
JsObject merged = newObj.merge(other);
JsObject merged2 = newObj.deepMerge(other);
String key1 = merged.field("key1").as(String.class);
}
for (String key1 : jsObj.field("key1").readOpt(String.class)) {
System.out.println("the value of key1 is : " + key1);
}Json.stringify(Json.arr("val1", "val2", "val3").append(Json.arr("val4", "val5")).add("val6")) // ["val1","val2","val3","val4","val5","val6"]
Json.arr("val1", "val2", "val3").append(Json.arr("val4", "val5")).add("val6").get(5) // val6import org.reactivecouchbase.json.*;
import static org.reactivecouchbase.json.Syntax.*;
import static org.reactivecouchbase.json.JsResult.*;
import static org.reactivecouchbase.json.DefaultReaders.*;
import static org.reactivecouchbase.json.ReaderConstraints.*;
Reader<User> userReader = new Reader<User>() {
@Override
public JsResult<User> read(JsValue value) {
try {
return new JsSuccess<User>(new User(
value.field("name").as(String.class),
value.field("surname").as(String.class),
value.field("age").as(Integer.class, validateWith(Integer.class, max( 99 ), min( 18 ))),
value.field("email").as(String.class, validateWith(String.class, matches( "^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)+$"))
));
} catch (Exception e) {
return new JsError<T>(new IllegalStateException("Ooops"));
}
}
};or using functionnal composition of JsResults
// Java 8 lambda syntax for shorter examples
Reader<User> userReader = new Reader<User>() {
@Override
public JsResult<User> read(JsValue value) {
return combine(
value.field("name").read(String.class),
value.field("surname").read(String.class),
value.field("age").read( validateWith( Integer.class, max( 99 ), min( 18 ))),
value.field("email").read( validateWith( String.class, matches( "^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)+$" ))
).map(tuple -> new User(tuple._1, tuple._2, tuple._3, tuple._4));
}
};
JsResult<T> userResult = Json.fromJson(Json.parse(...), userReader);
for (User user : userResult) {
System.out.println("Yeah user is : " + user.toString());
}
for (JsError<T> error : userResult.asError()) {
System.err.println("Error while reading a user : " + error.firstError());
}
for (JsSuccess<T> success : userResult.asSucces()) {
System.out.println("Yeah user is : " + success.get());
}
// Java 8 lambda syntax for shorter examples
userResult.filter(user -> user.age > 18).filterNot(user -> user.age < 99).map(user -> {
System.out.println("Yeah user is : " + user.toString());
});Writer<User> userWriter = new Writer<User>() {
public JsValue write(User user) {
return Json.obj(
$("name", user.name),
$("surname", user.surname),
$("age", user.age),
$("email", user.email),
$("gravatar", String.format("http://www.gravatar.com/avatar/%s?s=50&d=wavatar", Codec.md5(user.email))
);
}
};
JsObject user = Json.toJson(new User(...), userWriter).as(JsObject.class);