public void setSubnetId(String subnetId) {
        this.subnetId = subnetId;
    }
<p>
The ID of the subnet to launch the instance into.
</p>
<p>
If you specify a network interface, you must specify any subnets as part of the network interface instead of
using this parameter.
</p>

@param subnetId
       The ID of the subnet to launch the instance into.</p>
       <p>
       If you specify a network interface, you must specify any subnets as part of the network interface instead
       of using this parameter.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/RunInstancesRequest.java