Java

Firebase GET - Reading Data

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Demonstrates how to read parts of a Firebase JSON database. The data used in this example is at Chilkat Firebase Pigs Database, and is shown here:

Chilkat2 Java

import com.chilkatsoft.chilkat2.AuthGoogle;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.FileAccess;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Rest;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates how to read parts of a Firebase JSON database.

        // This example requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // This example assumes a JWT authentication token, if required, has been previously obtained.
        // See Get Firebase Access Token from JSON Service Account Private Key for sample code.

        // Load the previously obtained Firebase access token into a string.
        FileAccess fac = new FileAccess();
        String accessToken;
        try {
            accessToken = fac.readEntireTextFile("qa_data/tokens/firebaseToken.txt", "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Rest rest = new Rest();

        // Make the initial connection (without sending a request yet).
        // Once connected, any number of requests may be sent.  It is not necessary to explicitly
        // call Connect before each request.
        try {
            rest.connect("chilkat.firebaseio.com", 443, true, true);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // If authentication is required...
        AuthGoogle authGoogle = new AuthGoogle();
        authGoogle.setAccessToken(accessToken);
        rest.setAuthGoogle(authGoogle);

        // Chilkat's sample data (pig-rescue data) is publicly readable at: https://chilkat.firebaseio.com/.json

        // Let's get the animals with the shallow parameter so we can see how many pigs exist.
        String jsonResponse;
        try {
            jsonResponse = rest.fullRequestNoBody("GET", "/pig-rescue/animal.json?shallow=true");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // The JSON returned should look like this:
        // {"-KI3bD-FU_Dake7sYOiP":true,"-KI3bD-FU_Dake7sYOiT":true,"-KI3bD-FU_Dake7sYOiS":true,"-KI3bD-FU_Dake7sYOiU":true,"-KI3bD-FU_Dake7sYOiV":true,"-KI3bD-FU_Dake7sYOiR":true,"-KI3bD-FU_Dake7sYOiQ":true}
        System.out.println(jsonResponse);

        // Parse the response so we can iterate over each pig in the database..
        StringBuilder piggyPath = new StringBuilder();
        JsonObject shallow = new JsonObject();
        JsonObject piggyData = new JsonObject();
        shallow.load(jsonResponse);
        int count = shallow.getSize();
        int i = 0;
        while (i < count) {
            // Get each individual pig's data.
            piggyPath.clear();
            piggyPath.append("/pig-rescue/animal/");
            piggyPath.append(shallow.nameAt(i));
            piggyPath.append("/.json");

            String piggyJson;
            try {
                piggyJson = rest.fullRequestNoBody("GET", piggyPath.getAsString());
            } catch (ChilkatException e) {
                System.out.println(e.getLastErrorText());
                return;
            }

            // Show this piggy's data...
            // An example of one pig's data is shown here:
            // {"birth":"February, 1998","from":"Middle Ave.","gender":"F","in-date":"January, 2000",
            //   "name":"Molly II","picture":{"caption":"Molly in the Pasture","description":"Black pig","file":"molly_th.jpg"},
            //   "species":"pot belly pig","type":"Cathy's Herd"}
            System.out.println("---- " + i + " ----");
            System.out.println(piggyJson);

            // Let's get the pig's name, and the caption of the picture.
            piggyData.load(piggyJson);
            System.out.println("name: " + piggyData.stringOf("name"));
            System.out.println("caption: " + piggyData.stringOf("picture.caption"));

            i = i + 1;
        }

        // Note: In many of the Chilkat examples, you may notice strange ways
        // of doing something that should be simpler and shorter.  For example,
        // building the piggyPath (above) could've been written differently,
        // with some simple string concatenation.
        //
        // The reason is that the Chilkat examples are written in a
        // proprietary "example code" scripting language,
        // and then automatically generated to each of the different programming
        // languages you see on example-code.com.  The code generation is
        // limited in what it can do.  For example, string concatentation
        // is not yet a feature of the "example code" scripting language (as of May 2016),
        // and therefore you won't see the use of a programming language's string
        // concatentation operators in any example.
        //
    }
}