Java tutorial
/* * The MIT License * * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package hudson.widgets; import hudson.Functions; import hudson.model.ModelObject; import hudson.model.Run; import jenkins.widgets.HistoryPageEntry; import jenkins.widgets.HistoryPageFilter; import org.apache.commons.collections.IteratorUtils; import org.kohsuke.stapler.Header; import org.kohsuke.stapler.Stapler; import org.kohsuke.stapler.StaplerRequest; import org.kohsuke.stapler.StaplerResponse; import javax.annotation.CheckForNull; import javax.servlet.ServletException; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.List; /** * Displays the history of records (normally {@link Run}s) on the side panel. * * @param <O> * Owner of the widget. * @param <T> * Type individual record. * @author Kohsuke Kawaguchi */ public class HistoryWidget<O extends ModelObject, T> extends Widget { /** * The given data model of records. Newer ones first. */ public Iterable<T> baseList; /** * Indicates the next build number that client ajax should fetch. */ private String nextBuildNumberToFetch; /** * URL of the {@link #owner}. */ public final String baseUrl; public final O owner; private boolean trimmed; public final Adapter<? super T> adapter; final Long newerThan; final Long olderThan; final String searchString; /** * First transient build record. Everything >= this will be discarded when AJAX call is made. */ private String firstTransientBuildKey; /** * @param owner * The parent model object that owns this widget. */ public HistoryWidget(O owner, Iterable<T> baseList, Adapter<? super T> adapter) { StaplerRequest currentRequest = Stapler.getCurrentRequest(); this.adapter = adapter; this.baseList = baseList; this.baseUrl = Functions.getNearestAncestorUrl(currentRequest, owner); this.owner = owner; this.newerThan = getPagingParam(currentRequest, "newer-than"); this.olderThan = getPagingParam(currentRequest, "older-than"); this.searchString = currentRequest.getParameter("search"); ; } /** * Title of the widget. */ public String getDisplayName() { return Messages.BuildHistoryWidget_DisplayName(); } @Override public String getUrlName() { return "buildHistory"; } public String getFirstTransientBuildKey() { return firstTransientBuildKey; } private Iterable<HistoryPageEntry<T>> updateFirstTransientBuildKey(Iterable<HistoryPageEntry<T>> source) { String key = null; for (HistoryPageEntry<T> t : source) { if (adapter.isBuilding(t.getEntry())) { key = adapter.getKey(t.getEntry()); } } firstTransientBuildKey = key; return source; } /** * The records to be rendered this time. */ public Iterable<HistoryPageEntry<T>> getRenderList() { if (trimmed) { List<HistoryPageEntry<T>> pageEntries = toPageEntries(baseList); if (pageEntries.size() > THRESHOLD) { return updateFirstTransientBuildKey(pageEntries.subList(0, THRESHOLD)); } else { trimmed = false; return updateFirstTransientBuildKey(pageEntries); } } else { // to prevent baseList's concrete type from getting picked up by <j:forEach> in view return updateFirstTransientBuildKey(toPageEntries(baseList)); } } private List<HistoryPageEntry<T>> toPageEntries(Iterable<T> historyItemList) { Iterator<T> iterator = historyItemList.iterator(); if (!iterator.hasNext()) { return Collections.EMPTY_LIST; } List<HistoryPageEntry<T>> pageEntries = new ArrayList<HistoryPageEntry<T>>(); while (iterator.hasNext()) { pageEntries.add(new HistoryPageEntry<T>(iterator.next())); } return pageEntries; } /** * Get a {@link jenkins.widgets.HistoryPageFilter} for rendering a page of queue items. */ public HistoryPageFilter getHistoryPageFilter() { HistoryPageFilter<T> historyPageFilter = newPageFilter(); historyPageFilter.add(IteratorUtils.toList(baseList.iterator())); historyPageFilter.widget = this; return historyPageFilter; } protected HistoryPageFilter<T> newPageFilter() { HistoryPageFilter<T> historyPageFilter = new HistoryPageFilter<T>(THRESHOLD); if (newerThan != null) { historyPageFilter.setNewerThan(newerThan); } else if (olderThan != null) { historyPageFilter.setOlderThan(olderThan); } if (searchString != null) { historyPageFilter.setSearchString(searchString); } return historyPageFilter; } public boolean isTrimmed() { return trimmed; } public void setTrimmed(boolean trimmed) { this.trimmed = trimmed; } /** * Handles AJAX requests from browsers to update build history. * * @param n * The build 'number' to fetch. This is string because various variants * uses non-numbers as the build key. */ public void doAjax(StaplerRequest req, StaplerResponse rsp, @Header("n") String n) throws IOException, ServletException { rsp.setContentType("text/html;charset=UTF-8"); // pick up builds to send back List<T> items = new ArrayList<T>(); if (n != null) { String nn = null; // we'll compute next n here // list up all builds >=n. for (T t : baseList) { if (adapter.compare(t, n) >= 0) { items.add(t); if (adapter.isBuilding(t)) nn = adapter.getKey(t); // the next fetch should start from youngest build in progress } else break; } if (nn == null) { if (items.isEmpty()) { // nothing to report back. next fetch should retry the same 'n' nn = n; } else { // every record fetched this time is frozen. next fetch should start from the next build nn = adapter.getNextKey(adapter.getKey(items.get(0))); } } baseList = items; rsp.setHeader("n", nn); firstTransientBuildKey = nn; // all builds >= nn should be marked transient } HistoryPageFilter page = getHistoryPageFilter(); updateFirstTransientBuildKey(page.runs); req.getView(page, "ajaxBuildHistory.jelly").forward(req, rsp); } static final int THRESHOLD = Integer.getInteger(HistoryWidget.class.getName() + ".threshold", 30); public String getNextBuildNumberToFetch() { return nextBuildNumberToFetch; } public void setNextBuildNumberToFetch(String nextBuildNumberToFetch) { this.nextBuildNumberToFetch = nextBuildNumberToFetch; } public interface Adapter<T> { /** * If record is newer than the key, return a positive number. */ int compare(T record, String key); String getKey(T record); boolean isBuilding(T record); String getNextKey(String key); } private Long getPagingParam(@CheckForNull StaplerRequest currentRequest, @CheckForNull String name) { if (currentRequest == null || name == null) { return null; } String paramVal = currentRequest.getParameter(name); if (paramVal == null) { return null; } try { return new Long(paramVal); } catch (NumberFormatException nfe) { return null; } } }