I downloaded my service account credential json file from Firebase console placed it earlier in the main directory of GAE endpoint project when I run my backed locally it gives Security exception.
java.security.AccessControlException: access denied ("java.io.FilePermission" "\src\main\secret.json" "read")
I tried placing the .json file under the src directory also but no help.
I found a couple ways to approach this. First is by getting it from a file over an internet stream. The other is locally.
INTERNET WAY
My first method involved storing the file on my public dropbox folder. I got the shareable link (make sure it ends in .json) and pasted it in the string example "https://dl.dropboxusercontent.com/..EXAMPLE-CREDENTIALS"
/** A simple endpoint method that takes a name and says Hi back */
@ApiMethod(name = "sayHi")
public MyBean sayHi(@Named("name") String name) {
MyBean mModelClassObject = null;
String text = "";
try {
String line = "";
StringBuilder builder = new StringBuilder();
URL url = new URL("https://dl.dropboxusercontent.com/..EXAMPLE-CREDENTIALS");
BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
while ((line = reader.readLine()) != null) {
// ...
builder.append(line);
}
reader.close();
text = builder.toString();
} catch (MalformedURLException e) {
// ...
} catch (IOException e) {
// ...
}
InputStream stream = new ByteArrayInputStream(text.getBytes(StandardCharsets.UTF_8));
FirebaseOptions options = null;
options = new FirebaseOptions.Builder()
.setServiceAccount(stream)
.setDatabaseUrl("https://[PROJECT-ID].firebaseio.com/")
.build();
FirebaseApp.initializeApp(options);
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
final TaskCompletionSource<MyBean> tcs = new TaskCompletionSource<>();
Task<MyBean> tcsTask = tcs.getTask();
ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
MyBean result = dataSnapshot.getValue(MyBean.class);
if(result != null){
tcs.setResult(result);
}
}
@Override
public void onCancelled(DatabaseError databaseError){
//handle error
}
});
try {
mModelClassObject = Tasks.await(tcsTask);
}catch(ExecutionException e){
//handle exception
}catch (InterruptedException e){
//handle exception
}
return mModelClassObject;
}
LOCAL WAY
The other way is taking the version above and skipping something like dropbox
/** A simple endpoint method that takes a name and says Hi back */
@ApiMethod(name = "sayHi")
public MyBean sayHi(@Named("name") String name) {
MyBean mModelClassObject = null;
String text = "JUST PASTE YOUR JSON CONTENTS HERE";
InputStream stream = new ByteArrayInputStream(text.getBytes(StandardCharsets.UTF_8));
FirebaseOptions options = null;
options = new FirebaseOptions.Builder()
.setServiceAccount(stream)
.setDatabaseUrl("https://[PROJECT-ID].firebaseio.com/")
.build();
FirebaseApp.initializeApp(options);
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
final TaskCompletionSource<MyBean> tcs = new TaskCompletionSource<>();
Task<MyBean> tcsTask = tcs.getTask();
ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
MyBean result = dataSnapshot.getValue(MyBean.class);
if(result != null){
tcs.setResult(result);
}
}
@Override
public void onCancelled(DatabaseError databaseError){
//handle error
}
});
try {
mModelClassObject = Tasks.await(tcsTask);
}catch(ExecutionException e){
//handle exception
}catch (InterruptedException e){
//handle exception
}
return mModelClassObject;
}
I don't know if this follows best practice but my project is working now. I also included firebase's code for getting info. check out this answer to a question i asked recently on reading and writing to firebase.
EDIT
cleaned up version which doesnt throw errors
public class MyEndpoint {
private FirebaseOptions options;
private DatabaseReference ref;
private String serviceAccountJSON = "i took mine out for security reasons";
// create firebase instance if need be
private void connectToFirebase(){
if (options == null) {
options = null;
options = new FirebaseOptions.Builder()
.setServiceAccount(new ByteArrayInputStream(serviceAccountJSON.getBytes(StandardCharsets.UTF_8)))
.setDatabaseUrl("https://[PROJECT-ID].firebaseio.com/")
.build();
FirebaseApp.initializeApp(options);
}
if(ref == null) {
ref = FirebaseDatabase.getInstance().getReference();
}
}
/** A simple endpoint method that takes a name and says Hi back */
@ApiMethod(name = "sayHi")
public MyBean sayHi(@Named("name") String name) {
// always do this first
connectToFirebase();
MyBean mModelClassObject = null;
final TaskCompletionSource<MyBean> tcs = new TaskCompletionSource<>();
Task<MyBean> tcsTask = tcs.getTask();
// get the info
ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
MyBean result = dataSnapshot.getValue(MyBean.class);
if(result != null){
tcs.setResult(result);
}
}
@Override
public void onCancelled(DatabaseError databaseError){
//handle error
}
});
// wait for it
try {
mModelClassObject = Tasks.await(tcsTask);
}catch(ExecutionException e){
//handle exception
}catch (InterruptedException e){
//handle exception
}
mModelClassObject.setData(mModelClassObject.getData() + name);
return mModelClassObject;
}
}
Finally, I found the solution, Its written under the APIs and references section of Google App Engine in this link, that we need to add such files in the appengine-web.xml file under the <resource-files> tag, using <include path=""/> property. After doing so its works for me. I placed the .json file containing project credentials in the WEB-INF directory and then entered its relative path in <resource-files> tag.
