Unary RPC:這就是一般的rpc調用,一個請求對象對應一個返回對象
@Override
public void getFeature(Point request, StreamObserver<Feature> responseObserver) {
responseObserver.onNext(checkFeature(request));
responseObserver.onCompleted();
}
Server streaming RPC:一個請求對象,服務端可以傳回多個結果對象
@Override
public void listFeatures(Rectangle request, StreamObserver<Feature> responseObserver) {
int left = min(request.getLo().getLongitude(), request.getHi().getLongitude());
int right = max(request.getLo().getLongitude(), request.getHi().getLongitude());
int top = max(request.getLo().getLatitude(), request.getHi().getLatitude());
int bottom = min(request.getLo().getLatitude(), request.getHi().getLatitude());
for (Feature feature : features) {
if (!RouteGuideUtil.exists(feature)) {
continue;
}
int lat = feature.getLocation().getLatitude();
int lon = feature.getLocation().getLongitude();
if (lon >= left && lon <= right && lat >= bottom && lat <= top) {
responseObserver.onNext(feature);
}
}
responseObserver.onCompleted();
}
Client streaming RPC:客戶端傳入多個請求對象,服務端返回一個響應結果
@Override
public StreamObserver<Point> recordRoute(final StreamObserver<RouteSummary> responseObserver) {
return new StreamObserver<Point>() {
int pointCount;
int featureCount;
int distance;
Point previous;
final long startTime = System.nanoTime();
@Override
public void onNext(Point point) {
pointCount++;
if (RouteGuideUtil.exists(checkFeature(point))) {
featureCount++;
}
// For each point after the first, add the incremental distance from the previous point to
// the total distance value.
if (previous != null) {
distance += calcDistance(previous, point);
}
previous = point;
}
@Override
public void onError(Throwable t) {
logger.log(Level.WARNING, "recordRoute cancelled");
}
@Override
public void onCompleted() {
long seconds = NANOSECONDS.toSeconds(System.nanoTime() - startTime);
responseObserver.onNext(RouteSummary.newBuilder().setPointCount(pointCount)
.setFeatureCount(featureCount).setDistance(distance)
.setElapsedTime((int) seconds).build());
responseObserver.onCompleted();
}
};
}
Bidirectional streaming RPC:結合客戶端流式rpc和服務端流式rpc,可以傳入多個對象,返回多個響應對象
@Override
public StreamObserver<RouteNote> routeChat(final StreamObserver<RouteNote> responseObserver) {
return new StreamObserver<RouteNote>() {
@Override
public void onNext(RouteNote note) {
List<RouteNote> notes = getOrCreateNotes(note.getLocation());
// Respond with all previous notes at this location.
for (RouteNote prevNote : notes.toArray(new RouteNote[0])) {
responseObserver.onNext(prevNote);
}
// Now add the new note to the list
notes.add(note);
}
@Override
public void onError(Throwable t) {
logger.log(Level.WARNING, "routeChat cancelled");
}
@Override
public void onCompleted() {
responseObserver.onCompleted();
}
};
}