Activiti CRC Workflow Deployer

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.repository.Deployment;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.io.Resource;

public class WorkflowDeployer implements InitializingBean, ApplicationContextAware {

    static org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(WorkflowDeployer.class);

    private Resource[] deploymentResources;

    public void setDeploymentResources(Resource[] resources) {
        this.deploymentResources = resources;
    }

    private String category;

    public void setCategory(String category) {
        this.category = category;
    }

    ApplicationContext appCtx;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.appCtx = applicationContext;

    }

    @Override
    public void afterPropertiesSet() throws Exception {
        if (category == null)
            throw new FatalBeanException("Missing property: category");

        if (deploymentResources != null) {
            RepositoryService repositoryService = appCtx.getBean(RepositoryService.class);
            for (Resource r : deploymentResources) {

                String deploymentName = category + "_" + r.getFilename();
                String resourceName = r.getFilename();

                boolean doDeploy = true;
                List<Deployment> deployments = repositoryService.createDeploymentQuery().deploymentName(deploymentName).orderByDeploymenTime().desc().list();
                if (!deployments.isEmpty()) {
                    Deployment existing = deployments.get(0);
                    try {
                        InputStream in = repositoryService.getResourceAsStream(existing.getId(), resourceName);
                        if (in != null) {

                            File f = File.createTempFile("deployment","xml", new File(System.getProperty("java.io.tmpdir"), "deployment-temp"));
                            f.deleteOnExit();
                            OutputStream out=new FileOutputStream(f);
                            IOUtils.copy(in,out);
                            in.close();
                            out.close();

                            doDeploy =  (FileUtils.checksumCRC32(f) != FileUtils.checksumCRC32(r.getFile()));

                        }
                        else
                            throw new ActivitiException("Unable to read resource " + resourceName + ", input stream is null");
                    } catch (ActivitiException ex) {
                        //do nothing, simply re-deploy
                        log.error("Unable to read " + resourceName + " of deployment " + existing.getName() + ", id: " + existing.getId() + ", will re-deploy");
                    }

                }

                if (doDeploy) {
                    repositoryService.createDeployment()
                            .name(deploymentName)
                            .addInputStream(resourceName, r.getInputStream())
                            .deploy();
                    log.warn("Deployed BPMN20 resource " + r.getFilename());
                }

            }
        }
    }

}