Add filter that performs an HTTP query for a previously extract URL.

diff --git a/src/main/java/net/pterodactylus/rhynodge/filters/HttpQueryFilter.java b/src/main/java/net/pterodactylus/rhynodge/filters/HttpQueryFilter.java
new file mode 100644 (file)
index 0000000..2600288
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+++ b/src/main/java/net/pterodactylus/rhynodge/filters/HttpQueryFilter.java
@@ -0,0 +1,48 @@
+/*
+ * rhynodge - HttpQueryFilter.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.rhynodge.filters;
+
+import static com.google.common.base.Preconditions.*;
+
+import net.pterodactylus.rhynodge.Filter;
+import net.pterodactylus.rhynodge.State;
+import net.pterodactylus.rhynodge.queries.HttpQuery;
+import net.pterodactylus.rhynodge.states.HttpState;
+import net.pterodactylus.rhynodge.states.StringState;
+
+/**
+ * {@link Filter} implementation that uses the {@link StringState#value() value}
+ * of a {@link StringState} as a URL for {@link HttpQuery}, turning it into an
+ * {@link HttpState}.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class HttpQueryFilter implements Filter {
+
+       @Override
+       public State filter(State state) {
+               checkArgument(state instanceof StringState, "state must be a String state");
+
+               StringState stringState = (StringState) state;
+               String url = stringState.value();
+
+               HttpQuery query = new HttpQuery(url);
+               return query.state();
+       }
+
+}