initial support for entry filtering

pom.xml

@@ -191,6 +191,12 @@
 			<version>1.7.7</version>
 		</dependency>
 
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-jexl</artifactId>
+			<version>2.1.1</version>
+		</dependency>
+
 		<dependency>
 			<groupId>com.google.inject</groupId>
 			<artifactId>guice</artifactId>

src/main/java/com/commafeed/backend/feed/FeedEntryFilter.java

@@ -0,0 +1,89 @@
+package com.commafeed.backend.feed;
+
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+
+import org.apache.commons.jexl2.Expression;
+import org.apache.commons.jexl2.JexlContext;
+import org.apache.commons.jexl2.JexlEngine;
+import org.apache.commons.jexl2.JexlInfo;
+import org.apache.commons.jexl2.MapContext;
+import org.apache.commons.jexl2.introspection.JexlMethod;
+import org.apache.commons.jexl2.introspection.JexlPropertyGet;
+import org.apache.commons.jexl2.introspection.Uberspect;
+import org.apache.commons.jexl2.introspection.UberspectImpl;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.logging.LogFactory;
+
+import com.commafeed.backend.model.FeedEntry;
+
+@RequiredArgsConstructor
+public class FeedEntryFilter {
+
+	private static final JexlEngine ENGINE = initEngine();
+
+	private static JexlEngine initEngine() {
+		// classloader that prevents object creation
+		ClassLoader cl = new ClassLoader() {
+			@Override
+			public Class<?> loadClass(String name) throws ClassNotFoundException {
+				return null;
+			}
+
+			@Override
+			protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+				return null;
+			}
+		};
+
+		// uberspect that prevents access to .class and .getClass()
+		Uberspect uberspect = new UberspectImpl(LogFactory.getLog(JexlEngine.class)) {
+			@Override
+			public JexlPropertyGet getPropertyGet(Object obj, Object identifier, JexlInfo info) {
+				if ("class".equals(identifier)) {
+					return null;
+				}
+				return super.getPropertyGet(obj, identifier, info);
+			}
+
+			@Override
+			public JexlMethod getMethod(Object obj, String method, Object[] args, JexlInfo info) {
+				if ("getClass".equals(method)) {
+					return null;
+				}
+				return super.getMethod(obj, method, args, info);
+			}
+		};
+
+		JexlEngine engine = new JexlEngine(uberspect, null, null, null);
+		engine.setClassLoader(cl);
+		return engine;
+	}
+
+	private final String filter;
+
+	public boolean matchesEntry(FeedEntry entry) {
+		if (StringUtils.isBlank(filter)) {
+			return true;
+		}
+
+		Expression expression = ENGINE.createExpression(filter);
+
+		JexlContext context = new MapContext();
+		context.set("title", entry.getContent().getTitle().toLowerCase());
+		context.set("author", entry.getContent().getAuthor().toLowerCase());
+		context.set("content", entry.getContent().getContent().toLowerCase());
+		context.set("url", entry.getUrl().toLowerCase());
+
+		return (boolean) expression.evaluate(context);
+	}
+
+	@Data
+	private static class Model {
+		private String title;
+		private String author;
+		private String content;
+		private String url;
+	}
+
+}

src/main/java/com/commafeed/backend/feed/FeedRefreshUpdater.java

@@ -193,7 +193,7 @@ public class FeedRefreshUpdater implements Managed {
 				boolean inserted = new UnitOfWork<Boolean>(sessionFactory) {
 					@Override
 					protected Boolean runInSession() throws Exception {
-						return feedUpdateService.addEntry(feed, entry);
+						return feedUpdateService.addEntry(feed, entry, subscriptions);
 					}
 				}.run();
 				if (inserted) {

src/main/java/com/commafeed/backend/model/FeedSubscription.java

@@ -40,4 +40,7 @@ public class FeedSubscription extends AbstractModel {
 
 	private Integer position;
 
+	@Column(length = 4096)
+	private String filter = "author.contains('a')";
+
 }

src/main/java/com/commafeed/backend/service/FeedUpdateService.java

@@ -1,6 +1,7 @@
 package com.commafeed.backend.service;
 
 import java.util.Date;
+import java.util.List;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
@@ -10,21 +11,26 @@ import lombok.RequiredArgsConstructor;
 import org.apache.commons.codec.digest.DigestUtils;
 
 import com.commafeed.backend.dao.FeedEntryDAO;
+import com.commafeed.backend.dao.FeedEntryStatusDAO;
+import com.commafeed.backend.feed.FeedEntryFilter;
 import com.commafeed.backend.model.Feed;
 import com.commafeed.backend.model.FeedEntry;
 import com.commafeed.backend.model.FeedEntryContent;
+import com.commafeed.backend.model.FeedEntryStatus;
+import com.commafeed.backend.model.FeedSubscription;
 
 @RequiredArgsConstructor(onConstructor = @__({ @Inject }))
 @Singleton
 public class FeedUpdateService {
 
 	private final FeedEntryDAO feedEntryDAO;
+	private final FeedEntryStatusDAO feedEntryStatusDAO;
 	private final FeedEntryContentService feedEntryContentService;
 
 	/**
 	 * this is NOT thread-safe
 	 */
-	public boolean addEntry(Feed feed, FeedEntry entry) {
+	public boolean addEntry(Feed feed, FeedEntry entry, List<FeedSubscription> subscriptions) {
 
 		Long existing = feedEntryDAO.findExisting(entry.getGuid(), feed);
 		if (existing != null) {
@@ -36,8 +42,18 @@ public class FeedUpdateService {
 		entry.setContent(content);
 		entry.setInserted(new Date());
 		entry.setFeed(feed);
-
 		feedEntryDAO.saveOrUpdate(entry);
+
+		// if filter does not match the entry, mark it as read
+		for (FeedSubscription sub : subscriptions) {
+			FeedEntryFilter filter = new FeedEntryFilter(sub.getFilter());
+			if (!filter.matchesEntry(entry)) {
+				FeedEntryStatus status = new FeedEntryStatus(sub.getUser(), sub, entry);
+				status.setRead(true);
+				feedEntryStatusDAO.saveOrUpdate(status);
+			}
+		}
+
 		return true;
 	}
 }

src/main/resources/changelogs/db.changelog-2.1.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.1.xsd">
+
+	<changeSet id="add-sub-filter" author="athou">
+		<addColumn tableName="FEEDSUBSCRIPTIONS">
+			<column name="filter" type="varchar(4096)" />
+		</addColumn>
+	</changeSet>
+
+</databaseChangeLog>

src/main/resources/migrations.xml

@@ -9,5 +9,6 @@
 	<include file="changelogs/db.changelog-1.3.xml" />
 	<include file="changelogs/db.changelog-1.4.xml" />
 	<include file="changelogs/db.changelog-1.5.xml" />
+	<include file="changelogs/db.changelog-2.1.xml" />
 	
 </databaseChangeLog> 

src/test/java/com/commafeed/backend/feed/FeedEntryFilterTest.java

@@ -0,0 +1,64 @@
+package com.commafeed.backend.feed;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.commafeed.backend.model.FeedEntry;
+import com.commafeed.backend.model.FeedEntryContent;
+
+public class FeedEntryFilterTest {
+
+	private FeedEntry entry;
+	private FeedEntryContent content;
+
+	@Before
+	public void init() {
+		entry = new FeedEntry();
+		entry.setUrl("https://github.com/Athou/commafeed");
+
+		content = new FeedEntryContent();
+		content.setAuthor("Athou");
+		content.setTitle("Merge pull request #662 from Athou/dw8");
+		content.setContent("Merge pull request #662 from Athou/dw8");
+		entry.setContent(content);
+
+	}
+
+	@Test
+	public void emptyFilterMatchesFilter() {
+		FeedEntryFilter filter = new FeedEntryFilter(null);
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+	@Test
+	public void blankFilterMatchesFilter() {
+		FeedEntryFilter filter = new FeedEntryFilter("");
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+	@Test
+	public void simpleExpression() {
+		FeedEntryFilter filter = new FeedEntryFilter("author eq 'athou'");
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+	@Test
+	public void newIsDisabled() {
+		FeedEntryFilter filter = new FeedEntryFilter("null eq new ('java.lang.String', 'athou')");
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+	@Test
+	public void getClassMethodIsDisabled() {
+		FeedEntryFilter filter = new FeedEntryFilter("null eq ''.getClass()");
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+	@Test
+	public void dotClassIsDisabled() {
+		FeedEntryFilter filter = new FeedEntryFilter("null eq ''.class");
+		Assert.assertTrue(filter.matchesEntry(entry));
+	}
+
+}