edu.duke.cabig.c3pr.rules.deploy.SystemRulesDeployer.java Source code

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Here is the source code for edu.duke.cabig.c3pr.rules.deploy.SystemRulesDeployer.java

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/*******************************************************************************
 * Copyright Duke Comprehensive Cancer Center and SemanticBits
 * 
 * Distributed under the OSI-approved BSD 3-Clause License.
 * See http://ncip.github.com/c3pr/LICENSE.txt for details.
 ******************************************************************************/
package edu.duke.cabig.c3pr.rules.deploy;

import edu.duke.cabig.c3pr.rules.common.XMLUtil;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

public class SystemRulesDeployer {
    private static final Log log = LogFactory.getLog(SystemRulesDeployer.class);

    public SystemRulesDeployer(RuleDeploymentService ruleDeploymentService) {
        if (log.isInfoEnabled())
            log.info("Begining system rule loading......");
        try {

            // 1. create the base pattern.
            String pattern = "classpath*:" + SystemRulesDeployer.class.getPackage().getName().replace(".", "/")
                    + "/*.xml";

            // 2. Load the rule files, that are to be loaded in repository
            // and load them only if they are not already loaded.
            for (Resource resource : getResources(pattern)) {
                if (log.isDebugEnabled())
                    log.debug("Loading rule file :" + resource.getURL().toString());
                try {
                    String ruleXml = getFileContext(resource.getInputStream());
                    org.drools.rule.Package rulePackage = XMLUtil.unmarshalToPackage(ruleXml);
                    String ruleBindUri = rulePackage.getName();
                    // unregister the rules
                    try {
                        ruleDeploymentService.deregisterRuleSet(ruleBindUri);
                    } catch (Exception ignore) {
                    }
                    // register the rules
                    if (log.isDebugEnabled())
                        log.debug("Registering at bindUri : " + ruleBindUri + "\r\n\r\n" + ruleXml);
                    ruleDeploymentService.registerRulePackage(ruleBindUri, rulePackage);
                    if (log.isDebugEnabled())
                        log.debug("Sucessfully deployed rule at bindUri :" + ruleBindUri);
                } catch (RuntimeException e) {
                    log.debug("It seems the system rule is already available, so ignoring", e);
                }

            }

        } catch (Exception e) {
            log.warn("Error while loading system rules :", e);
        }
        if (log.isInfoEnabled())
            log.debug("Finished system rule loading......");
    }

    public static Resource[] getResources(String pattern) throws IOException {
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        if (log.isDebugEnabled())
            log.debug("Looking for resources matching " + pattern);
        Resource[] resources = resolver.getResources(pattern);
        return resources;
    }

    public static String getFileContext(InputStream in) throws Exception {
        BufferedReader ds = new BufferedReader(new InputStreamReader(in));
        String line = null;
        StringBuffer xml = new StringBuffer();
        while ((line = ds.readLine()) != null) {
            xml.append(line);
        }
        return xml.toString();
    }

}