Atkārtojiet JSON masīva Java
Lai lasītu un rakstītu JSON datus Java, mēs izmantojam org.json bibliotēka. The org.json bibliotēka ļauj mums kodēt un atšifrēt JSON datus Java. The org.json klase nodrošina vairākas svarīgas klases, caur kurām mēs varam veikt vairākas darbības ar šiem JSON datiem. Šīs klases ir šādas:
- JSONObject
- JSONValue
- JSONArray
- JSONNumurs
- JSONString
Šīs ir šādas darbības, lai atkārtotu JSON masīvu Java:
1) Izveidojiet a Maven projektēt un pievienot json atkarība iekšā POM.xml failu.
org.json json 20160810
2) Izveidojiet JSON datu virkni, ko mēs pārvēršam par JSON objektu, lai manipulētu ar tā datiem.
3) Pēc tam mēs iegūstam JSON masīvu no JSON objekta, izmantojot getJSONArray() metodi un saglabājiet to JSONArray tipa mainīgajā.
4) getJSONArray() metode izmanto masīva nosaukumu kā virkni, ko izgūt no objekta.
5) Pēc tam mēs izmantojam for cilpu no 0 līdz JSONArray.length(). Metode garums() atgriež masīva lielumu.
6) Mēs saglabājam katru indeksa ierakstu JSONObject. Lai iegūtu konkrēta indeksa JSON objektu, mēs izmantojam JSONArray metodi getJSONObject().
7) Lai iegūtu norādītā lauka vērtību, mēs izmantojam JSONObject metodi get(), nododot lauka nosaukumu kā virkni metodē get().
JSONExample.java
// import required packages package javaTpoint.JSONExample; //import required classes import org.json.JSONArray; import org.json.JSONObject; // create JSONExample class to iterate JSON Array public class JSONExample{ //main() method start public static void main(String args[]){ // create an string of JSON data String jsonData = '{'locations':[{'lat':'23.053','long':'72.629','location':'ABC','address':'DEF','city':'Ahmedabad','state':'Gujrat','phonenumber':'1234567'},{'lat':'21.013','long':'52.619','location':'XYZ','address':'MNP','city':'Ghaziabad','state':'UP','phonenumber':'212321'}]}'; // convert JSON string into JSON Object using JSONObject() method JSONObject json = new JSONObject(jsonData); // get locations array from the JSON Object and store it into JSONArray JSONArray jsonArray = json.getJSONArray('locations'); // Iterate jsonArray using for loop for (int i = 0; i <jsonarray.length(); i++) { store each object in jsonobject explrobject="jsonArray.getJSONObject(i);" get field value from using get() method system.out.println(explrobject.get('address')); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/10/iterate-json-array-java-2.webp" alt="Iterate JSON Array Java"> <p> <strong>JSONExample2.java</strong> </p> <pre> //import package package javaTpoint.JSONExample; // import require classes import java.io.FileWriter; import java.io.IOException; import org.json.simple.JSONArray; import org.json.simple.JSONObject; // create class JSONExample1 public class JSONExample1 { // main() method start public static void main(String[] args) { // create instance of JSONObject JSONObject jsonObject = new JSONObject(); // use put() method for inserting the data into JSON object jsonObject.put('name', 'Abhishek Sharma'); jsonObject.put('department','B.E'); jsonObject.put('branch', 'C.S.E'); jsonObject.put('year', 3); //create JSON Array and store record into JSONObject JSONArray list1 = new JSONArray(); list1.add('Julia'); list1.add('Paul'); list1.add('Emma'); jsonObject.put('Names', list1); JSONArray list2 = new JSONArray(); list2.add('BCA'); list2.add('B.Tech'); list2.add('MCA'); jsonObject.put('Course', list2); JSONArray list3 = new JSONArray(); list3.add('3'); list3.add('4'); list3.add('2'); jsonObject.put('Year', list3); // create instance of the FileWriter class by passing the path of the file in the constructor try (FileWriter file = new FileWriter('D:\newfile.json')) { // use write() method to add JSONObject into file file.write(jsonObject.toJSONString()); file.flush(); } catch (IOException e) { e.printStackTrace(); } // get locations array from the JSON Object and store it into JSONArray JSONArray jsonArray = (JSONArray) jsonObject.get('Names'); // Iterate jsonArray using for loop for (int i = 0; i <jsonarray.size(); i++) { get field value from json array system.out.println(jsonarray.get(i)); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/10/iterate-json-array-java-3.webp" alt="Iterate JSON Array Java"> <hr></jsonarray.size();></pre></jsonarray.length();>
