Question: I am using 

```
Ubuntu 12.04
Neo4j - Graph Database Kernel 2.0.0-M04
javac 1.7.0_25
java version "1.7.0_25
Java(TM) SE Runtime Environment (build 1.7.0_25-b15)

```

Even though, I am using Oracle Java, I was getting warning:

```
"WARNING! You are using an unsupported Java runtime. Please use Oracle(R) Java(TM) Runtime Environment 7."

```

When I debug `utils file` in neo4j directory, I found a function with following comment:

```
 # check if running JDK 6, warn if not
checkjvmcompatibility() {

  $JAVACMD -version 2>&1 | egrep -q "Java HotSpot\\(TM\\) (64-Bit Server|Client) VM"

  if [ $? -eq 1 ]
  then
    echo "WARNING! You are using an unsupported Java runtime. Please use Oracle(R) Java(TM) Runtime Environment 7."
  else
    $JAVACMD -version 2>&1 | egrep -q "java version \"1.7"
    if [ $? -eq 1 ]
    then
      echo "WARNING! You are using an unsupported version of the Java runtime. Please use Oracle(R) Java(TM) Runtime Environment 7."
    fi
  fi
}

```

Some confusion : 

```
comment of function shows that it is checking for java 6 but error message displayed use 'echo' shows that you are not using java run time 7.

```

So actually what Java is being expected by neo4j ? 

I was using Oracle-Java-1.7 still it was throwing me error not using Oracle-Java1.7 .

Thanks
Amit Aggarwal

Answer: 
Neo4j 2.0 is supposed to run with Java 7 only. I guess the comment in the script is misleading. Please make `JAVA_HOME` points to the right directory. On linux this is not necessary valid if `java -version` shows version 7. 

```
 JAVA_HOME=/usr/lib/jvm/java-7-oracle

```

To check which version Neo4j is actually using run

```
grep "JVM information" -A 5 <neo4j_dir>/data/graph.db/messages.log

```
It is a bug, I got

```
ERROR! Neo4j cannot be started using java version 1.7.0_25.
...
http://localhost:7474/ is ready.

```

So it seems to start up OK, even though it gives this error message.