Adding getLastError(), getPreviousError(), resetError()

geir · geir · commit 9f7f18016664 · 2009-02-09T18:03:21.000-05:00
and forceError() for testing
diff --git a/examples/QuickTour.java b/examples/QuickTour.java
@@ -158,5 +158,43 @@ public static void main(String[] args) throws Exception {
         for (DBObject o : list) {
             System.out.println(o);
         }
+
+        /*
+         *  See if the last operation had an error
+         */
+        System.out.println("Last error : " + db.getLastError());
+
+        /*
+         *  see if any previous operation had an error
+         */
+        System.out.println("Previous error : " + db.getPreviousError());
+
+        /*
+         *  force an error
+         */
+
+        db.forceError();
+
+        /*
+         *  See if the last operation had an error
+         */
+        System.out.println("Last error : " + db.getLastError());
+
+        /*
+         *  see if any previous operation had an error
+         */
+        System.out.println("Previous error : " + db.getPreviousError());
+
+        /*
+         *  See if the last operation had an error
+         */
+        System.out.println("Last error : " + db.getLastError());
+
+        db.resetError();
+
+        /*
+         *  see if any previous operation had an error
+         */
+        System.out.println("Previous error : " + db.getPreviousError());
     }
 }
diff --git a/src/main/com/mongodb/DBApiLayer.java b/src/main/com/mongodb/DBApiLayer.java
@@ -91,6 +91,55 @@ public boolean authenticate(String username, String passwd) {
         return res.getInt("ok") == 1;
     }
 
+    /**
+     *  Gets the the error (if there is one) from the previous operation.  The result of
+     *  this command will look like
+     *
+     *  <pre>
+     * { "err" :  errorMessage  , "ok" : 1.0 , "_ns" : "$cmd"}
+     * </pre>
+     *
+     * The value for errorMessage will be null if no error occurred, or a description otherwise.
+     *
+     *  @return DBObject with error and status information
+     */
+    public DBObject getLastError() {
+        return command(new BasicDBObject("getlasterror", 1));
+    }
+
+    /**
+     *  Returns the last error that occurred since start of database or a call to <code>resetError()</code>
+     *
+     *  The return object will look like
+     *
+     *  <pre>
+     * { err : errorMessage, nPrev : countOpsBack, ok : 1 }
+     *  </pre>
+     *
+     * The value for errormMessage will be null of no error has ocurred, or the message.  The value of
+     * countOpsBack will be the number of operations since the error occurred.
+     * 
+     * @return DBObject with error and status information
+     */
+    public DBObject getPreviousError() {
+        return command(new BasicDBObject("getpreverror", 1));
+    }
+
+    /**
+     *  Resets the error memory for this database.  Used to clear all errors such that getPreviousError()
+     *  will return no error.
+     */
+    public void resetError() {
+        command(new BasicDBObject("reseterror", 1));
+    }
+
+    /**
+     *  For testing purposes only - this method forces an error to help test error handling
+     */
+    public void forceError() {
+        command(new BasicDBObject("forceerror", 1));
+    }
+
     /**
      *  Drops this database.  Removes all data on disk.  Use with caution.
      */
diff --git a/src/test/com/mongodb/ErrorTest.java b/src/test/com/mongodb/ErrorTest.java
@@ -0,0 +1,73 @@
+/**
+ *  See the NOTICE.txt file distributed with this work for
+ *  information regarding copyright ownership.
+ *
+ *  The authors license this file to you under the
+ *  Apache License, Version 2.0 (the "License"); you may not use
+ *  this file except in compliance with the License.  You may
+ *  obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package com.mongodb;
+
+import org.testng.annotations.Test;
+import org.testng.annotations.BeforeClass;
+
+/**
+ *
+ */
+public class ErrorTest {
+
+    Mongo _db;
+
+    @BeforeClass
+    public void setUp() throws Exception{
+        _db = new Mongo("com_mongodb_ErrorTest");
+    }
+
+    @Test
+    public void testLastError() {
+
+        assert(_db.getLastError().get("err") == null);
+
+        _db.forceError();
+
+        assert(_db.getLastError().get("err") != null);
+
+        _db.resetError();
+        assert(_db.getLastError().get("err") == null);
+    }
+
+    @Test
+    public void testPrevError() {
+
+        _db.resetError();
+        
+        assert(_db.getLastError().get("err") == null);
+        assert(_db.getPreviousError().get("err") == null);
+
+        _db.forceError();
+
+        assert(_db.getLastError().get("err") != null);
+        assert(_db.getPreviousError().get("err") != null);
+
+        _db.getCollection("misc").insert(new BasicDBObject("foo", 1));
+
+        assert(_db.getLastError().get("err") == null);
+        assert(_db.getPreviousError().get("err") != null);
+
+        _db.resetError();
+
+        assert(_db.getLastError().get("err") == null);
+        assert(_db.getPreviousError().get("err") == null);
+    }
+
+}
diff --git a/testng.xml b/testng.xml
@@ -12,6 +12,8 @@
       <class name="com.mongodb.ReflectionTest" />
       <class name="com.mongodb.DBAddressTest" />
 
+      <class name="com.mongodb.ErrorTest" />
+
     </classes>
   </test>
 
