public void setMetricName(String metricName) {
        this.metricName = metricName;
    }
<p>
The name for the metric associated with the alarm. For each <code>PutMetricAlarm</code> operation, you must
specify either <code>MetricName</code> or a <code>Metrics</code> array.
</p>
<p>
If you are creating an alarm based on a math expression, you cannot specify this parameter, or any of the
<code>Namespace</code>, <code>Dimensions</code>, <code>Period</code>, <code>Unit</code>, <code>Statistic</code>,
or <code>ExtendedStatistic</code> parameters. Instead, you specify all this information in the
<code>Metrics</code> array.
</p>

@param metricName
       The name for the metric associated with the alarm. For each <code>PutMetricAlarm</code> operation, you
       must specify either <code>MetricName</code> or a <code>Metrics</code> array.</p>
       <p>
       If you are creating an alarm based on a math expression, you cannot specify this parameter, or any of the
       <code>Namespace</code>, <code>Dimensions</code>, <code>Period</code>, <code>Unit</code>,
       <code>Statistic</code>, or <code>ExtendedStatistic</code> parameters. Instead, you specify all this
       information in the <code>Metrics</code> array.
aws-java-sdk-cloudwatch/src/main/java/com/amazonaws/services/cloudwatch/model/PutMetricAlarmRequest.java