Use Log4J pattern to generate collection name, fix for test data cleanup.

spring-data-mongodb-log4j/src/main/java/org/springframework/data/document/mongodb/log4j/MongoLog4jAppender.java

@@ -28,6 +28,8 @@ import com.mongodb.Mongo;
 import com.mongodb.WriteConcern;
 import org.apache.log4j.AppenderSkeleton;
 import org.apache.log4j.Level;
+import org.apache.log4j.MDC;
+import org.apache.log4j.PatternLayout;
 import org.apache.log4j.spi.LoggingEvent;
 
 /**
@@ -42,11 +44,16 @@ public class MongoLog4jAppender extends AppenderSkeleton {
   public static final String PROPERTIES = "properties";
   public static final String TRACEBACK = "traceback";
   public static final String MESSAGE = "message";
+  public static final String YEAR = "year";
+  public static final String MONTH = "month";
+  public static final String DAY = "day";
+  public static final String HOUR = "hour";
 
   protected String host = "localhost";
   protected int port = 27017;
   protected String database = "logs";
-  protected String collection = null;
+  protected String collectionPattern = "%c";
+  protected PatternLayout collectionLayout = new PatternLayout(collectionPattern);
   protected String applicationId = System.getProperty("APPLICATION_ID", null);
   protected WriteConcern warnOrHigherWriteConcern = WriteConcern.SAFE;
   protected WriteConcern infoOrLowerWriteConcern = WriteConcern.NORMAL;
@@ -84,12 +91,13 @@ public class MongoLog4jAppender extends AppenderSkeleton {
     this.database = database;
   }
 
-  public String getCollection() {
-    return collection;
+  public String getCollectionPattern() {
+    return collectionPattern;
   }
 
-  public void setCollection(String collection) {
-    this.collection = collection;
+  public void setCollectionPattern(String collectionPattern) {
+    this.collectionPattern = collectionPattern;
+    this.collectionLayout = new PatternLayout(collectionPattern);
   }
 
   public String getApplicationId() {
@@ -133,7 +141,10 @@ public class MongoLog4jAppender extends AppenderSkeleton {
     }
 
     BasicDBObject dbo = new BasicDBObject();
-    dbo.put(APP_ID, applicationId);
+    if (null != applicationId) {
+      dbo.put(APP_ID, applicationId);
+      MDC.put(APP_ID, applicationId);
+    }
     dbo.put(NAME, event.getLogger().getName());
     dbo.put(LEVEL, event.getLevel().toString());
     Calendar tstamp = Calendar.getInstance();
@@ -162,19 +173,20 @@ public class MongoLog4jAppender extends AppenderSkeleton {
     dbo.put(MESSAGE, event.getRenderedMessage());
 
     // Insert the document
-    String coll;
-    if (null == collection) {
-      // Use the category name
-      coll = event.getLogger().getName();
-    } else {
-      Calendar now = Calendar.getInstance();
-      coll = String.format(collection,
-          now.get(Calendar.YEAR),
-          now.get(Calendar.MONTH + 1),
-          now.get(Calendar.DAY_OF_MONTH),
-          now.get(Calendar.HOUR_OF_DAY),
-          event.getLevel().toString(),
-          event.getLogger().getName());
+    Calendar now = Calendar.getInstance();
+    MDC.put(YEAR, now.get(Calendar.YEAR));
+    MDC.put(MONTH, String.format("%1$02d", now.get(Calendar.MONTH) + 1));
+    MDC.put(DAY, String.format("%1$02d", now.get(Calendar.DAY_OF_MONTH)));
+    MDC.put(HOUR, String.format("%1$02d", now.get(Calendar.HOUR_OF_DAY)));
+
+    String coll = collectionLayout.format(event);
+
+    MDC.remove(YEAR);
+    MDC.remove(MONTH);
+    MDC.remove(DAY);
+    MDC.remove(HOUR);
+    if (null != applicationId) {
+      MDC.remove(APP_ID);
     }
 
     WriteConcern wc;

spring-data-mongodb-log4j/src/test/java/org/springframework/data/document/mongodb/log4j/AppenderTest.java

@@ -20,6 +20,7 @@ import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
 import java.net.UnknownHostException;
+import java.util.Calendar;
 
 import com.mongodb.DB;
 import com.mongodb.DBCursor;
@@ -38,13 +39,16 @@ public class AppenderTest {
   private Logger log = Logger.getLogger(NAME);
   private Mongo mongo;
   private DB db;
+  private String collection;
 
   @Before
   public void setup() {
     try {
       mongo = new Mongo("localhost", 27017);
       db = mongo.getDB("logs");
-      db.getCollection(NAME).drop();
+      Calendar now = Calendar.getInstance();
+      collection = String.valueOf(now.get(Calendar.YEAR)) + String.format("%1$02d", now.get(Calendar.MONTH) + 1);
+      db.getCollection(collection).drop();
     } catch (UnknownHostException e) {
       throw new RuntimeException(e.getMessage(), e);
     }
@@ -57,7 +61,7 @@ public class AppenderTest {
     log.warn("WARN message");
     log.error("ERROR message");
 
-    DBCursor msgs = db.getCollection(NAME).find();
+    DBCursor msgs = db.getCollection(collection).find();
     assertThat(msgs.count(), is(4));
 
   }

spring-data-mongodb-log4j/src/test/resources/log4j.properties

@@ -6,7 +6,7 @@ log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - <%m>%n
 log4j.appender.stdout.host = localhost
 log4j.appender.stdout.port = 27017
 log4j.appender.stdout.database = logs
-log4j.appender.stdout.collection = %1$4d%2$02d%3$02d
+log4j.appender.stdout.collectionPattern = %X{year}%X{month}
 log4j.appender.stdout.applicationId = my.application
 log4j.appender.stdout.warnOrHigherWriteConcern = FSYNC_SAFE