gui/servlet/embedded/src/main/java/org/apache/batchee/servlet/JBatchController.java - geronimo-batchee - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.batchee.servlet;

 import javax.batch.operations.BatchRuntimeException;
 import javax.batch.operations.JobExecutionNotRunningException;
 import javax.batch.operations.JobOperator;
 import javax.batch.operations.NoSuchJobExecutionException;
 import javax.batch.runtime.BatchRuntime;
 import javax.batch.runtime.JobExecution;
 import javax.batch.runtime.JobInstance;
 import javax.batch.runtime.StepExecution;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 public class JBatchController extends HttpServlet {
     private static final String DEFAULT_MAPPING_SERVLET25 = "/jbatch";
     private static final int DEFAULT_PAGE_SIZE = 30;

     public static final String FORM_JOB_NAME = "___batchee_job_name___";

     private static final String EXECUTIONS_MAPPING = "/executions/";
     private static final String STEP_EXECUTIONS_MAPPING = "/step-executions/";
     private static final String START_MAPPING = "/start/";
     private static final String DO_START_MAPPING = "/doStart/";
     private static final String VIEW_MAPPING = "/view/";
     private static final String SIMPLEREST_MAPPING = "/rest/";

     private JobOperator operator;
     private SimpleRestController simpleRestController;

     private String context;
     private String mapping = DEFAULT_MAPPING_SERVLET25;
     private int executionByPage = DEFAULT_PAGE_SIZE;
     private boolean readOnly = false;
     private boolean defaultScan = false;
     private final Set<String> appBatches = new HashSet<String>();

     public JBatchController mapping(final String rawMapping) {
         this.mapping = rawMapping.substring(0, rawMapping.length() - 2); // mapping pattern is /xxx/*
         return this;
     }

     public JBatchController executionByPage(final int byPage) {
         executionByPage = byPage;
         return this;
     }

     public JBatchController readOnly(final boolean readOnly) {
         this.readOnly = readOnly;
         return this;
     }

     public JBatchController defaultScan(final boolean defaultScan) {
         this.defaultScan = defaultScan;
         return this;
     }

     @Override
     public void init(final ServletConfig config) throws ServletException {
         this.operator = BatchRuntime.getJobOperator();

         this.context = config.getServletContext().getContextPath();
         if ("/".equals(context)) {
             context = "";
         }

         mapping = context + mapping;
         this.simpleRestController = new SimpleRestController(operator);

         // this is not perfect but when it works it list jobs not executed yet which is helpful
         // try to find not yet started jobs
         if (defaultScan) {
             final ClassLoader loader = Thread.currentThread().getContextClassLoader();
             final Enumeration<URL> resources;
             try {
                 resources = loader.getResources("META-INF/batch-jobs");
             } catch (final IOException e) {
                 return;
             }
             while (resources.hasMoreElements()) {
                 final URL url = resources.nextElement();
                 final File file = toFile(url);

                 if (file != null) {
                     if (file.isDirectory()) {
                         findInDirectory(file);
                     } else {
                         findInJar(file);
                     }
                 }
             }
         }
     }


     @Override
     protected void service(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
         resp.setContentType("text/html");
         resp.setCharacterEncoding("UTF-8");
         req.setAttribute("context", context);
         req.setAttribute("mapping", mapping);

         final String path = req.getPathInfo();
         if (path != null && path.startsWith(EXECUTIONS_MAPPING)) {
             final String name = URLDecoder.decode(path.substring(EXECUTIONS_MAPPING.length()), "UTF-8");
             final int start = extractInt(req, "start", -1);
             listExecutions(req, name, executionByPage, start);
         } else if (path != null && path.startsWith(STEP_EXECUTIONS_MAPPING)) {
             final int executionId = Integer.parseInt(path.substring(STEP_EXECUTIONS_MAPPING.length()));
             listStepExecutions(req, executionId);
         } else if (path != null && path.startsWith(VIEW_MAPPING)) {
             final String name = URLDecoder.decode(path.substring(VIEW_MAPPING.length()), "UTF-8");
             view(req, name);
         } else if (path != null && path.startsWith(START_MAPPING)) {
             if (readOnly) {
                 reportReadOnly(req);
             } else {
                 final String name = URLDecoder.decode(path.substring(START_MAPPING.length()), "UTF-8");
                 start(req, name);
             }
         } else if (path != null && path.startsWith(DO_START_MAPPING)) {
             if (readOnly) {
                 reportReadOnly(req);
             } else {
                 String name = URLDecoder.decode(path.substring(DO_START_MAPPING.length()), "UTF-8");
                 if (name.isEmpty()) {
                     name = req.getParameter(FORM_JOB_NAME);
                 }

                 doStart(req, name, readProperties(req));
             }
         } else if (path != null && path.startsWith(SIMPLEREST_MAPPING)) {
             simpleRestController.dispatch(req, resp, path.substring(SIMPLEREST_MAPPING.length()));
             return; // simple REST handles all the response itself
         } else {
             listJobs(req);
         }

         req.getRequestDispatcher("/internal/batchee/layout.jsp").forward(req, resp);
     }

     private void reportReadOnly(final HttpServletRequest req) {
         req.setAttribute("view", "read-only");
     }

     private void view(final HttpServletRequest req, final String name) {
         req.setAttribute("name", name);
         req.setAttribute("view", "view");

         // we copy the logic from jbatch module since the GUI is not (yet?) linked to our impl
         final ClassLoader tccl = Thread.currentThread().getContextClassLoader();
         final String relativePath = "META-INF/batch-jobs/" + name + ".xml";
         final InputStream stream = tccl.getResourceAsStream(relativePath);
         if (stream == null) {
             throw new BatchRuntimeException(new FileNotFoundException("Cannot find an XML for " + name));
         }

         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         int r;
         try {
             while ((r = stream.read()) != -1) {
                 baos.write(r);
             }
         } catch (final IOException e) {
             throw new BatchRuntimeException(new FileNotFoundException("Cannot find an XML for " + name));
         }

         req.setAttribute("content", new String(baos.toByteArray())
                                     .replace("&","&amp;")
                                     .replace("<", "&lt;")
                                     .replace(">", "&gt;")
                                     .replace("\"", "&quot;")
                                     .replace("'", "&apos;"));
     }

     private void doStart(final HttpServletRequest req, final String name, final Properties properties) {
         req.setAttribute("id", operator.start(name, properties));
         req.setAttribute("name", name);
         req.setAttribute("view", "after-start");
     }

     private void start(final HttpServletRequest req, final String name) {
         req.setAttribute("view", "start");
         req.setAttribute("name", name);
     }

     private void listStepExecutions(final HttpServletRequest req, final int executionId) {
         final List<StepExecution> steps = operator.getStepExecutions(executionId);
         req.setAttribute("view", "step-executions");
         req.setAttribute("steps", steps);
         req.setAttribute("executionId", executionId);
         req.setAttribute("name", operator.getJobExecution(executionId).getJobName());
     }

     private void listExecutions(final HttpServletRequest req, final String name, final int pageSize, final int inStart) {
         if (!readOnly) { // can be an auto refresh asking for a stop
             final String stopId = req.getParameter("stop");
             if (stopId != null) {
                 try {
                     operator.stop(Long.parseLong(stopId));
                 } catch (final NoSuchJobExecutionException nsje) {
                     // no-op
                 } catch (final JobExecutionNotRunningException nsje) {
                     // no-op
                 }
             }
         } else {
             reportReadOnly(req);
             return;
         }

         final int jobInstanceCount = operator.getJobInstanceCount(name);

         int start = inStart;
         if (start == -1) { // first page is last page
             start = Math.max(0, jobInstanceCount - pageSize);
         }

         final List<JobInstance> instances = new ArrayList<JobInstance>(operator.getJobInstances(name, start, pageSize));
         Collections.sort(instances, JobInstanceIdComparator.INSTANCE);

         final Map<JobInstance, List<JobExecution>> executions = new LinkedHashMap<JobInstance, List<JobExecution>>();
         for (final JobInstance instance : instances) {
             executions.put(instance, operator.getJobExecutions(instance));
         }

         req.setAttribute("view", "job-instances");
         req.setAttribute("name", name);
         req.setAttribute("executions", executions);

         int nextStart = start + pageSize;
         if (nextStart > jobInstanceCount) {
             nextStart = -1;
         }
         req.setAttribute("nextStart", nextStart);

         req.setAttribute("previousStart", start - pageSize);

         if (jobInstanceCount > pageSize) {
             req.setAttribute("lastStart", Math.max(0, jobInstanceCount - pageSize));
         } else {
             req.setAttribute("lastStart", -1);
         }
     }

     private void listJobs(final HttpServletRequest req) throws ServletException, IOException {
         final Set<String> names = new HashSet<String>(appBatches);
         final Set<String> registered = operator.getJobNames();
         if (registered != null) {
             names.addAll(registered);
         }

         req.setAttribute("view", "jobs");
         req.setAttribute("names", names);
     }

     private static int extractInt(final HttpServletRequest req, final String name, final int defaultValue) {
         final String string = req.getParameter(name);
         if (string != null) {
             return Integer.parseInt(string);
         }
         return defaultValue;
     }

     private static Properties readProperties(final HttpServletRequest req) {
         final Map<String, String> map = new HashMap<String, String>();
         final Enumeration<String> names = req.getParameterNames();
         while (names.hasMoreElements()) {
             final String key = names.nextElement();
             if (FORM_JOB_NAME.equals(key)) {
                 continue;
             }

             map.put(key, req.getParameter(key));
         }

         final Properties properties = new Properties();
         for (final Map.Entry<String, String> entry : map.entrySet()) {
             final String key = entry.getKey();
             if (key.startsWith("k_")) {
                 final String name = key.substring("k_".length());
                 properties.setProperty(name, map.get("v_" + name));
             }
         }
         return properties;
     }

     private Collection<String> findInJar(final File file) {
         final Pattern pattern = Pattern.compile("META\\-INF/batch-jobs/\\(*\\).xml");
         final JarFile jar;
         try {
             jar = new JarFile(file);
         } catch (final IOException e) {
             return Collections.emptySet();
         }
         final Enumeration<JarEntry> entries = jar.entries();
         final Collection<String> values = new HashSet<String>();
         while (entries.hasMoreElements()) {
             final JarEntry entry = entries.nextElement();
             final Matcher matcher = pattern.matcher(entry.getName());
             if (matcher.matches()) {
                 values.add(matcher.group(1));
             }
         }
         return values;
     }

     private Collection<String> findInDirectory(final File file) {
         final String[] batches = file.list(new FilenameFilter() {
             @Override
             public boolean accept(final File dir, final String name) {
                 return name.endsWith(".xml");
             }
         });
         if (batches != null) {
             final Collection<String> values = new HashSet<String>();
             for (final String batch : batches) {
                 values.add(batch.substring(0, batch.length() - ".xml".length()));
             }
             return values;
         }
         return Collections.emptySet();
     }

     private static File toFile(final URL url) {
         final File file;
         final String externalForm = url.toExternalForm();
         if ("jar".equals(url.getProtocol())) {
             file = new File(externalForm.substring("jar:".length(), externalForm.lastIndexOf('!')));
         } else if ("file".equals(url.getProtocol())) {
             file = new File(externalForm.substring("file:".length()));
         } else {
             file = null;
         }
         return file;
     }

     private static class JobInstanceIdComparator implements java.util.Comparator<JobInstance> {
         private static final JobInstanceIdComparator INSTANCE = new JobInstanceIdComparator();

         @Override
         public int compare(final JobInstance o1, final JobInstance o2) {
             return (int) (o2.getInstanceId() - o1.getInstanceId()); // reverse order since users will prefer last first
         }
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.apache.batchee.servlet;

	import javax.batch.operations.BatchRuntimeException;
	import javax.batch.operations.JobExecutionNotRunningException;
	import javax.batch.operations.JobOperator;
	import javax.batch.operations.NoSuchJobExecutionException;
	import javax.batch.runtime.BatchRuntime;
	import javax.batch.runtime.JobExecution;
	import javax.batch.runtime.JobInstance;
	import javax.batch.runtime.StepExecution;
	import javax.servlet.ServletConfig;
	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import java.io.ByteArrayOutputStream;
	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.FilenameFilter;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.URL;
	import java.net.URLDecoder;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Enumeration;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Properties;
	import java.util.Set;
	import java.util.jar.JarEntry;
	import java.util.jar.JarFile;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	public class JBatchController extends HttpServlet {
	private static final String DEFAULT_MAPPING_SERVLET25 = "/jbatch";
	private static final int DEFAULT_PAGE_SIZE = 30;

	public static final String FORM_JOB_NAME = "___batchee_job_name___";

	private static final String EXECUTIONS_MAPPING = "/executions/";
	private static final String STEP_EXECUTIONS_MAPPING = "/step-executions/";
	private static final String START_MAPPING = "/start/";
	private static final String DO_START_MAPPING = "/doStart/";
	private static final String VIEW_MAPPING = "/view/";
	private static final String SIMPLEREST_MAPPING = "/rest/";

	private JobOperator operator;
	private SimpleRestController simpleRestController;

	private String context;
	private String mapping = DEFAULT_MAPPING_SERVLET25;
	private int executionByPage = DEFAULT_PAGE_SIZE;
	private boolean readOnly = false;
	private boolean defaultScan = false;
	private final Set<String> appBatches = new HashSet<String>();

	public JBatchController mapping(final String rawMapping) {
	this.mapping = rawMapping.substring(0, rawMapping.length() - 2); // mapping pattern is /xxx/*
	return this;
	}

	public JBatchController executionByPage(final int byPage) {
	executionByPage = byPage;
	return this;
	}

	public JBatchController readOnly(final boolean readOnly) {
	this.readOnly = readOnly;
	return this;
	}

	public JBatchController defaultScan(final boolean defaultScan) {
	this.defaultScan = defaultScan;
	return this;
	}

	@Override
	public void init(final ServletConfig config) throws ServletException {
	this.operator = BatchRuntime.getJobOperator();

	this.context = config.getServletContext().getContextPath();
	if ("/".equals(context)) {
	context = "";
	}

	mapping = context + mapping;
	this.simpleRestController = new SimpleRestController(operator);

	// this is not perfect but when it works it list jobs not executed yet which is helpful
	// try to find not yet started jobs
	if (defaultScan) {
	final ClassLoader loader = Thread.currentThread().getContextClassLoader();
	final Enumeration<URL> resources;
	try {
	resources = loader.getResources("META-INF/batch-jobs");
	} catch (final IOException e) {
	return;
	}
	while (resources.hasMoreElements()) {
	final URL url = resources.nextElement();
	final File file = toFile(url);

	if (file != null) {
	if (file.isDirectory()) {
	findInDirectory(file);
	} else {
	findInJar(file);
	}
	}
	}
	}
	}


	@Override
	protected void service(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
	resp.setContentType("text/html");
	resp.setCharacterEncoding("UTF-8");
	req.setAttribute("context", context);
	req.setAttribute("mapping", mapping);

	final String path = req.getPathInfo();
	if (path != null && path.startsWith(EXECUTIONS_MAPPING)) {
	final String name = URLDecoder.decode(path.substring(EXECUTIONS_MAPPING.length()), "UTF-8");
	final int start = extractInt(req, "start", -1);
	listExecutions(req, name, executionByPage, start);
	} else if (path != null && path.startsWith(STEP_EXECUTIONS_MAPPING)) {
	final int executionId = Integer.parseInt(path.substring(STEP_EXECUTIONS_MAPPING.length()));
	listStepExecutions(req, executionId);
	} else if (path != null && path.startsWith(VIEW_MAPPING)) {
	final String name = URLDecoder.decode(path.substring(VIEW_MAPPING.length()), "UTF-8");
	view(req, name);
	} else if (path != null && path.startsWith(START_MAPPING)) {
	if (readOnly) {
	reportReadOnly(req);
	} else {
	final String name = URLDecoder.decode(path.substring(START_MAPPING.length()), "UTF-8");
	start(req, name);
	}
	} else if (path != null && path.startsWith(DO_START_MAPPING)) {
	if (readOnly) {
	reportReadOnly(req);
	} else {
	String name = URLDecoder.decode(path.substring(DO_START_MAPPING.length()), "UTF-8");
	if (name.isEmpty()) {
	name = req.getParameter(FORM_JOB_NAME);
	}

	doStart(req, name, readProperties(req));
	}
	} else if (path != null && path.startsWith(SIMPLEREST_MAPPING)) {
	simpleRestController.dispatch(req, resp, path.substring(SIMPLEREST_MAPPING.length()));
	return; // simple REST handles all the response itself
	} else {
	listJobs(req);
	}

	req.getRequestDispatcher("/internal/batchee/layout.jsp").forward(req, resp);
	}

	private void reportReadOnly(final HttpServletRequest req) {
	req.setAttribute("view", "read-only");
	}

	private void view(final HttpServletRequest req, final String name) {
	req.setAttribute("name", name);
	req.setAttribute("view", "view");

	// we copy the logic from jbatch module since the GUI is not (yet?) linked to our impl
	final ClassLoader tccl = Thread.currentThread().getContextClassLoader();
	final String relativePath = "META-INF/batch-jobs/" + name + ".xml";
	final InputStream stream = tccl.getResourceAsStream(relativePath);
	if (stream == null) {
	throw new BatchRuntimeException(new FileNotFoundException("Cannot find an XML for " + name));
	}

	final ByteArrayOutputStream baos = new ByteArrayOutputStream();
	int r;
	try {
	while ((r = stream.read()) != -1) {
	baos.write(r);
	}
	} catch (final IOException e) {
	throw new BatchRuntimeException(new FileNotFoundException("Cannot find an XML for " + name));
	}

	req.setAttribute("content", new String(baos.toByteArray())
	.replace("&","&")
	.replace("<", "<")
	.replace(">", ">")
	.replace("\"", """)
	.replace("'", "'"));
	}

	private void doStart(final HttpServletRequest req, final String name, final Properties properties) {
	req.setAttribute("id", operator.start(name, properties));
	req.setAttribute("name", name);
	req.setAttribute("view", "after-start");
	}

	private void start(final HttpServletRequest req, final String name) {
	req.setAttribute("view", "start");
	req.setAttribute("name", name);
	}

	private void listStepExecutions(final HttpServletRequest req, final int executionId) {
	final List<StepExecution> steps = operator.getStepExecutions(executionId);
	req.setAttribute("view", "step-executions");
	req.setAttribute("steps", steps);
	req.setAttribute("executionId", executionId);
	req.setAttribute("name", operator.getJobExecution(executionId).getJobName());
	}

	private void listExecutions(final HttpServletRequest req, final String name, final int pageSize, final int inStart) {
	if (!readOnly) { // can be an auto refresh asking for a stop
	final String stopId = req.getParameter("stop");
	if (stopId != null) {
	try {
	operator.stop(Long.parseLong(stopId));
	} catch (final NoSuchJobExecutionException nsje) {
	// no-op
	} catch (final JobExecutionNotRunningException nsje) {
	// no-op
	}
	}
	} else {
	reportReadOnly(req);
	return;
	}

	final int jobInstanceCount = operator.getJobInstanceCount(name);

	int start = inStart;
	if (start == -1) { // first page is last page
	start = Math.max(0, jobInstanceCount - pageSize);
	}

	final List<JobInstance> instances = new ArrayList<JobInstance>(operator.getJobInstances(name, start, pageSize));
	Collections.sort(instances, JobInstanceIdComparator.INSTANCE);

	final Map<JobInstance, List<JobExecution>> executions = new LinkedHashMap<JobInstance, List<JobExecution>>();
	for (final JobInstance instance : instances) {
	executions.put(instance, operator.getJobExecutions(instance));
	}

	req.setAttribute("view", "job-instances");
	req.setAttribute("name", name);
	req.setAttribute("executions", executions);

	int nextStart = start + pageSize;
	if (nextStart > jobInstanceCount) {
	nextStart = -1;
	}
	req.setAttribute("nextStart", nextStart);

	req.setAttribute("previousStart", start - pageSize);

	if (jobInstanceCount > pageSize) {
	req.setAttribute("lastStart", Math.max(0, jobInstanceCount - pageSize));
	} else {
	req.setAttribute("lastStart", -1);
	}
	}

	private void listJobs(final HttpServletRequest req) throws ServletException, IOException {
	final Set<String> names = new HashSet<String>(appBatches);
	final Set<String> registered = operator.getJobNames();
	if (registered != null) {
	names.addAll(registered);
	}

	req.setAttribute("view", "jobs");
	req.setAttribute("names", names);
	}

	private static int extractInt(final HttpServletRequest req, final String name, final int defaultValue) {
	final String string = req.getParameter(name);
	if (string != null) {
	return Integer.parseInt(string);
	}
	return defaultValue;
	}

	private static Properties readProperties(final HttpServletRequest req) {
	final Map<String, String> map = new HashMap<String, String>();
	final Enumeration<String> names = req.getParameterNames();
	while (names.hasMoreElements()) {
	final String key = names.nextElement();
	if (FORM_JOB_NAME.equals(key)) {
	continue;
	}

	map.put(key, req.getParameter(key));
	}

	final Properties properties = new Properties();
	for (final Map.Entry<String, String> entry : map.entrySet()) {
	final String key = entry.getKey();
	if (key.startsWith("k_")) {
	final String name = key.substring("k_".length());
	properties.setProperty(name, map.get("v_" + name));
	}
	}
	return properties;
	}

	private Collection<String> findInJar(final File file) {
	final Pattern pattern = Pattern.compile("META\\-INF/batch-jobs/\\(*\\).xml");
	final JarFile jar;
	try {
	jar = new JarFile(file);
	} catch (final IOException e) {
	return Collections.emptySet();
	}
	final Enumeration<JarEntry> entries = jar.entries();
	final Collection<String> values = new HashSet<String>();
	while (entries.hasMoreElements()) {
	final JarEntry entry = entries.nextElement();
	final Matcher matcher = pattern.matcher(entry.getName());
	if (matcher.matches()) {
	values.add(matcher.group(1));
	}
	}
	return values;
	}

	private Collection<String> findInDirectory(final File file) {
	final String[] batches = file.list(new FilenameFilter() {
	@Override
	public boolean accept(final File dir, final String name) {
	return name.endsWith(".xml");
	}
	});
	if (batches != null) {
	final Collection<String> values = new HashSet<String>();
	for (final String batch : batches) {
	values.add(batch.substring(0, batch.length() - ".xml".length()));
	}
	return values;
	}
	return Collections.emptySet();
	}

	private static File toFile(final URL url) {
	final File file;
	final String externalForm = url.toExternalForm();
	if ("jar".equals(url.getProtocol())) {
	file = new File(externalForm.substring("jar:".length(), externalForm.lastIndexOf('!')));
	} else if ("file".equals(url.getProtocol())) {
	file = new File(externalForm.substring("file:".length()));
	} else {
	file = null;
	}
	return file;
	}

	private static class JobInstanceIdComparator implements java.util.Comparator<JobInstance> {
	private static final JobInstanceIdComparator INSTANCE = new JobInstanceIdComparator();

	@Override
	public int compare(final JobInstance o1, final JobInstance o2) {
	return (int) (o2.getInstanceId() - o1.getInstanceId()); // reverse order since users will prefer last first
	}
	}
	}