Java Requires Chilkat v11.0.0+

Lower-Level REST API Methods (Google Cloud Storage)

See more REST Examples

The FullRequest* methods, such as FullRequestBinary, FullRequestMultipart, FullRequestNoBody, FullRequestStream, FullRequestString, etc. are high-level REST API methods that both send the request and receive the response. It is often the case that an application needs make a REST call, but with a finer level of control. The Chilkat REST API provides this feature. An application can break a REST call into the following parts:

1. Send the HTTP request. (via the SendReq* methods)
2. Receive the HTTP response header. (ReadResponseHeader)
3. Receive the HTTP response body. (via the ReadRespBody* methods)

This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.

Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.
        // It will create a bucket in Google Cloud Storage.

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

        AuthGoogle gAuth = new AuthGoogle();
        // Obtain an access token as shown in one of the following examples:
        // See Get Access Token using a Service Account JSON Key
        // See Get Access Token using a P12 File

        Rest rest = new Rest();

        // Connect using TLS.
        boolean bAutoReconnect = true;
        rest.connect("www.googleapis.com", 443, true, bAutoReconnect);

        // Provide the authentication credentials (i.e. the access key)
        rest.setAuthGoogle(gAuth);

        // Build the JSON request body for creating a bucket.
        // The only required property is the "name", but we'll add more
        // to make a better example..
        JsonObject jsonReqBody = new JsonObject();
        jsonReqBody.addStringAt(-1, "name", "chilkat-bucket-c");
        jsonReqBody.addStringAt(-1, "kind", "storage#bucket");
        jsonReqBody.addStringAt(-1, "location", "US");

        JsonObject objVersioning = new JsonObject();
        jsonReqBody.appendObject2("versioning", objVersioning);
        objVersioning.addBoolAt(-1, "enabled", true);

        // Show the HTTP request body we'll be sending.
        System.out.println(jsonReqBody.emit());

        // Add the required query parameter.
        // See https://cloud.google.com/storage/docs/json_api/v1/buckets/insert
        rest.addQueryParam("project", "chilkattest-1050");

        // Add the Content-Type HTTP request header.
        rest.addHeader("Content-Type", "application/json; charset=UTF-8");

        // Send the REST HTTP request.
        try {
            rest.sendReqStringBody("POST", "/storage/v1/b", jsonReqBody.emit());
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Read the response header.
        int responseStatusCode = rest.readResponseHeader();
        if (responseStatusCode < 0) {
            // We were unable to receive the response header.
            System.out.println(rest.getLastErrorText());
            return;
        }

        if (responseStatusCode != 200) {
            // The response was not successful.  We'll still need to receive
            // the response body, which may contain an error message from the server.
            // If the response has no body, then the method for reading the
            // response body can still be called.  It will simply return with an empty
            // response body.

            // We can examine the response header and status text:
            System.out.println("Response status text: " + rest.getResponseStatusText());
            System.out.println("Response header: " + rest.getResponseHeader());
        }

        // Read the response body.  In this case we're expecting it to be JSON..
        String responseBodyStr;
        try {
            responseBodyStr = rest.readRespBodyString();
        } catch (ChilkatException e) {
            // We were unable to receive the response body.
            // Note: If the response did not include a body (such as for cases where
            // the Content-Length header is 0, or if the response status code implicitly
            // indicates no body, then ReadRespBodyString returns cktrue, and the
            // responseBodyString will be an empty string.
            System.out.println(e.getLastErrorText());
            return;
        }

        // Show the JSON response.
        System.out.println("Json Response: " + responseBodyStr);
    }
}