Beginner's help!

Greeting everyone, I'm a computer/ electronical engineer with a physics Ph.D background. I'm new to the Hadoop scene on Fedora 17 linux, I have Apache Hadoop, Hive, Pig, and Sqoop, and Spring installed. Every time I execute it from any of the programs from terminal, I get the following output:

Code:

[eddie_nygma@localhost ~]$ hadoop +======================================================================+ | Error: JAVA_HOME is not set and Java could not be found | +----------------------------------------------------------------------+ | Please download the latest Sun JDK from the Sun Java web site | | > http://java.sun.com/javase/downloads/ < | | | | Hadoop requires Java 1.6 or later. | | NOTE: This script will find Sun Java whether you install using the | | binary or the RPM based installer. | +======================================================================+

So after researching up the problem it turns out I need edit my /etc/hadoop-0.20/conf/hadoop-env.sh file, what's going on here, I checked the config file and here are the default settings:

Code:

# Set Hadoop-specific environment variables here. # The only required environment variable is JAVA_HOME. All others are # optional. When running a distributed configuration it is best to # set JAVA_HOME in this file, so that it is correctly defined on # remote nodes. # The java implementation to use. Required. # export JAVA_HOME=/usr/lib/j2sdk1.5-sun # Extra Java CLASSPATH elements. Optional. # export HADOOP_CLASSPATH= # The maximum amount of heap to use, in MB. Default is 1000. # export HADOOP_HEAPSIZE=2000 # Extra Java runtime options. Empty by default. # export HADOOP_OPTS=-server # Command specific options appended to HADOOP_OPTS when specified export HADOOP_NAMENODE_OPTS="-Dcom.sun.management.jmxremote $HADOOP_NAMENODE_OPTS" export HADOOP_SECONDARYNAMENODE_OPTS="-Dcom.sun.management.jmxremote $HADOOP_SECONDARYNAMENODE_OPTS" export HADOOP_DATANODE_OPTS="-Dcom.sun.management.jmxremote $HADOOP_DATANODE_OPTS" export HADOOP_BALANCER_OPTS="-Dcom.sun.management.jmxremote $HADOOP_BALANCER_OPTS" export HADOOP_JOBTRACKER_OPTS="-Dcom.sun.management.jmxremote $HADOOP_JOBTRACKER_OPTS" # export HADOOP_TASKTRACKER_OPTS= # The following applies to multiple commands (fs, dfs, fsck, distcp etc) # export HADOOP_CLIENT_OPTS # Extra ssh options. Empty by default. # export HADOOP_SSH_OPTS="-o ConnectTimeout=1 -o SendEnv=HADOOP_CONF_DIR" # Where log files are stored. $HADOOP_HOME/logs by default. # export HADOOP_LOG_DIR=${HADOOP_HOME}/logs # File naming remote slave hosts. $HADOOP_HOME/conf/slaves by default. # export HADOOP_SLAVES=${HADOOP_HOME}/conf/slaves # host:path where hadoop code should be rsync'd from. Unset by default. # export HADOOP_MASTER=master:/home/$USER/src/hadoop # Seconds to sleep between slave commands. Unset by default. This # can be useful in large clusters, where, e.g., slave rsyncs can # otherwise arrive faster than the master can service them. # export HADOOP_SLAVE_SLEEP=0.1 # The directory where pid files are stored. /tmp by default. # export HADOOP_PID_DIR=/var/hadoop/pids # A string representing this instance of hadoop. $USER by default. # export HADOOP_IDENT_STRING=$USER # The scheduling priority for daemon processes. See 'man nice'. # export HADOOP_NICENESS=10

So my question is, since I've never edited a config file before 'cause I'm a newbie to linux, what lines in this file do I need to edit and what do lines of code do I need to put in it's place, that is, how should the default settings lines look in order to get Hadoop running?