Lire fichier Json

Bonjour,

J'ai récupéré des fichier json de openstreetmap qui sont sous cette forme:

Code:

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{"id": "75101","citycode": "75101","type": "city","name": "1er Arrondissement","postcode": "75001","lat": "48.859815","lon": "2.340315","city": "1er Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 17.6, "adm_weight": 2, "importance": 0.3844}
{"id": "75102","citycode": "75102","type": "city","name": "2e Arrondissement","postcode": "75002","lat": "48.866110","lon": "2.340235","city": "2e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 22.4, "adm_weight": 2, "importance": 0.3903}
{"id": "75103","citycode": "75103","type": "city","name": "3e Arrondissement","postcode": "75003","lat": "48.863523","lon": "2.360715","city": "3e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 35.7, "adm_weight": 2, "importance": 0.4017}
{"id": "75104","citycode": "75104","type": "city","name": "4e Arrondissement","postcode": "75004","lat": "48.856278","lon": "2.351263","city": "4e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 28.2, "adm_weight": 2, "importance": 0.3959}
...

Je souhaite les lire en java.
J'avais penser à jackson mais je voit pas comment faire car d'après ce que je vois, le fichier ne contient pas une array, mais pour chaque adresse, c'est un nouvel objet dans une fichier, ce n'est pas un nouvel objet dans une array list.

Merci de votre aide

Tu as pensé à faire un split sur la String, en prenant par exemple le caractère }. Ensuite tu le rajoute à la fin de chaque string, et tu as logiquement un String[] qui contient tes objets, parsable un par un avec jackson. Ou alors, tu rajoute [ au début, ] à la fin, tu fait un replace sur les } par }, et tu as un array json...

Comment faire pour la première solution en java surtout que le fichier ressemble plutôt à ceci:

Code:

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{"id": "75101","citycode": "75101","type": "city","name": "1er Arrondissement","postcode": "75001","lat": "48.859815","lon": "2.340315","city": "1er Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 17.6, "adm_weight": 2, "importance": 0.3844}
{"id": "75102","citycode": "75102","type": "city","name": "2e Arrondissement","postcode": "75002","lat": "48.866110","lon": "2.340235","city": "2e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 22.4, "adm_weight": 2, "importance": 0.3903}
{"id": "75103","citycode": "75103","type": "city","name": "3e Arrondissement","postcode": "75003","lat": "48.863523","lon": "2.360715","city": "3e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 35.7, "adm_weight": 2, "importance": 0.4017}
{"id": "75104","citycode": "75104","type": "city","name": "4e Arrondissement","postcode": "75004","lat": "48.856278","lon": "2.351263","city": "4e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 28.2, "adm_weight": 2, "importance": 0.3959}
{"id": "75105","citycode": "75105","type": "city","name": "5e Arrondissement","postcode": "75005","lat": "48.845442","lon": "2.343222","city": "5e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 61.5, "adm_weight": 2, "importance": 0.4147}
{"id": "75106","citycode": "75106","type": "city","name": "6e Arrondissement","postcode": "75006","lat": "48.850777","lon": "2.332253","city": "6e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 43.1, "adm_weight": 2, "importance": 0.4062}
{"id": "75107","citycode": "75107","type": "city","name": "7e Arrondissement","postcode": "75007","lat": "48.857003","lon": "2.319907","city": "7e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 57.4, "adm_weight": 2, "importance": 0.4131}
{"id": "75108","citycode": "75108","type": "city","name": "8e Arrondissement","postcode": "75008","lat": "48.876772","lon": "2.316921","city": "8e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 40.3, "adm_weight": 2, "importance": 0.4046}
{"id": "75109","citycode": "75109","type": "city","name": "9e Arrondissement","postcode": "75009","lat": "48.871499","lon": "2.338804","city": "9e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 60.3, "adm_weight": 2, "importance": 0.4143}
{"id": "75110","citycode": "75110","type": "city","name": "10e Arrondissement","postcode": "75010","lat": "48.871595","lon": "2.356526","city": "10e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 95.9, "adm_weight": 2, "importance": 0.4252}
{"id": "75111","citycode": "75111","type": "city","name": "11e Arrondissement","postcode": "75011","lat": "48.858221","lon": "2.378499","city": "11e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 152.7, "adm_weight": 2, "importance": 0.4360}
{"id": "75112","citycode": "75112","type": "city","name": "12e Arrondissement","postcode": "75012","lat": "48.840277","lon": "2.386887","city": "12e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 142.9, "adm_weight": 2, "importance": 0.4345}
{"id": "75113","citycode": "75113","type": "city","name": "13e Arrondissement","postcode": "75013","lat": "48.832011","lon": "2.354290","city": "13e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 182.0, "adm_weight": 2, "importance": 0.4400}
{"id": "75114","citycode": "75114","type": "city","name": "14e Arrondissement","postcode": "75014","lat": "48.832753","lon": "2.325672","city": "14e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 137.2, "adm_weight": 2, "importance": 0.4335}
{"id": "75115","citycode": "75115","type": "city","name": "15e Arrondissement","postcode": "75015","lat": "48.840698","lon": "2.299681","city": "15e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 236.5, "adm_weight": 2, "importance": 0.4459}
{"id": "75116","citycode": "75116","type": "city","name": "16e Arrondissement","postcode": "75016","lat": "48.863042","lon": "2.276208","city": "16e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 169.4, "adm_weight": 2, "importance": 0.4384}
{"id": "75117","citycode": "75117","type": "city","name": "17e Arrondissement","postcode": "75017","lat": "48.883989","lon": "2.320918","city": "17e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 168.5, "adm_weight": 2, "importance": 0.4382}
{"id": "75118","citycode": "75118","type": "city","name": "18e Arrondissement","postcode": "75018","lat": "48.891312","lon": "2.344008","city": "18e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 200.6, "adm_weight": 2, "importance": 0.4422}
{"id": "75119","citycode": "75119","type": "city","name": "19e Arrondissement","postcode": "75019","lat": "48.882516","lon": "2.380936","city": "19e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 184.8, "adm_weight": 2, "importance": 0.4403}
{"id": "75120","citycode": "75120","type": "city","name": "20e Arrondissement","postcode": "75020","lat": "48.864621","lon": "2.398869","city": "20e Arrondissement","departement": "Paris", "region": "Île-de-France", "population": 197.1, "adm_weight": 2, "importance": 0.4418}
{"id": "751010414A","citycode": "75101","type": "street","name": "Rue de l'Arc en Ciel","postcode": "75001","lat": "48.862150","lon": "2.346096","city": "Paris","departement": "Paris", "region": "Île-de-France","importance": 0.0923 ,"housenumbers":{"17": {"lat": 48.862150,"lon": 2.346096}}}
{"id": "751010891U","citycode": "75101","type": "street","name": "Porte Berger","postcode": "75001","lat": "48.862219","lon": "2.345456","city": "Paris","departement": "Paris", "region": "Île-de-France","importance": 0.0923 ,"housenumbers":{"101": {"lat": 48.862219,"lon": 2.345456}}}

Hello,

en réalité Jackson est tout à fait capable de lire un flux au fur et à mesure, et de ce fait il est tout à fait capable de lire des objets JSON qui se suivent, même si des objets JSON les uns à la suite des autres ça ne fait pas un JSON valide.

Supposons que je veuille lire le fichier names.json suivant :
Code:

1 2 3 {"name": "Pierre"} {"name": "Paul"} {"name": "Jacques"}
Ce n'est pas du JSON valable, mais ce sont trois objets JSON valables. Même situation donc.

Je définis d'abord un classe qui représente de tels objets :
Code:

1 2 3 4 5 6 7 8 9 10 11 public class Person { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } }
Puis je lis mon fichier comme ceci :
Code:

1 2 3 4 5 6 7 JsonFactory factory = new ObjectMapper().getFactory(); try (JsonParser parser = factory.createParser(new File("names.json"))) { while (parser.nextToken() != null) { Person person = parser.readValueAs(Person.class); System.out.println(person.getName()); } }