Java tutorial
/* * Copyright 2000-2011 JetBrains s.r.o. * * Licensed 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 com.intellij.openapi.paths; import com.intellij.codeHighlighting.HighlightDisplayLevel; import com.intellij.codeInsight.intention.IntentionAction; import com.intellij.lang.annotation.Annotation; import com.intellij.lang.annotation.AnnotationHolder; import com.intellij.lang.annotation.ExternalAnnotator; import com.intellij.openapi.diagnostic.Logger; import com.intellij.openapi.util.TextRange; import com.intellij.psi.PsiAnchor; import com.intellij.psi.PsiElement; import com.intellij.psi.PsiFile; import com.intellij.psi.PsiReference; import com.intellij.util.containers.HashMap; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.cookie.CookiePolicy; import org.apache.commons.httpclient.methods.GetMethod; import org.jetbrains.annotations.NotNull; import org.jetbrains.annotations.Nullable; import java.io.IOException; import java.net.UnknownHostException; import java.util.Arrays; import java.util.Collection; import java.util.Map; /** * @author Eugene.Kudelevsky */ public abstract class WebReferencesAnnotatorBase extends ExternalAnnotator<WebReferencesAnnotatorBase.MyInfo[], WebReferencesAnnotatorBase.MyInfo[]> { private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.paths.WebReferencesAnnotatorBase"); private final Map<String, MyFetchCacheEntry> myFetchCache = new HashMap<String, MyFetchCacheEntry>(); private final Object myFetchCacheLock = new Object(); private static final long FETCH_CACHE_TIMEOUT = 10000; protected static final WebReference[] EMPTY_ARRAY = new WebReference[0]; @NotNull protected abstract WebReference[] collectWebReferences(@NotNull PsiFile file); @Nullable protected static WebReference lookForWebReference(@NotNull PsiElement element) { return lookForWebReference(Arrays.asList(element.getReferences())); } @SuppressWarnings("unchecked") @Nullable private static WebReference lookForWebReference(Collection<PsiReference> references) { for (PsiReference reference : references) { if (reference instanceof WebReference) { return (WebReference) reference; } else if (reference instanceof PsiDynaReference) { final WebReference webReference = lookForWebReference( ((PsiDynaReference) reference).getReferences()); if (webReference != null) { return webReference; } } } return null; } @Override public MyInfo[] collectInformation(@NotNull PsiFile file) { final WebReference[] references = collectWebReferences(file); final MyInfo[] infos = new MyInfo[references.length]; for (int i = 0; i < infos.length; i++) { final WebReference reference = references[i]; infos[i] = new MyInfo(PsiAnchor.create(reference.getElement()), reference.getRangeInElement(), reference.getValue()); } return infos; } @Override public MyInfo[] doAnnotate(MyInfo[] infos) { final MyFetchResult[] fetchResults = new MyFetchResult[infos.length]; for (int i = 0; i < fetchResults.length; i++) { fetchResults[i] = checkUrl(infos[i].myUrl); } boolean containsAvailableHosts = false; for (MyFetchResult fetchResult : fetchResults) { if (fetchResult != MyFetchResult.UNKNOWN_HOST) { containsAvailableHosts = true; } } for (int i = 0; i < fetchResults.length; i++) { final MyFetchResult result = fetchResults[i]; // if all hosts are not available, internet connection may be disabled, so it's better to not report warnings for unknown hosts if (result == MyFetchResult.OK || (!containsAvailableHosts && result == MyFetchResult.UNKNOWN_HOST)) { infos[i].myResult = true; } } return infos; } @Override public void apply(@NotNull PsiFile file, MyInfo[] infos, @NotNull AnnotationHolder holder) { if (infos.length == 0) { return; } final HighlightDisplayLevel displayLevel = getHighlightDisplayLevel(file); for (MyInfo info : infos) { if (!info.myResult) { final PsiElement element = info.myAnchor.retrieve(); if (element != null) { final int start = element.getTextRange().getStartOffset(); final TextRange range = new TextRange(start + info.myRangeInElement.getStartOffset(), start + info.myRangeInElement.getEndOffset()); final String message = getErrorMessage(info.myUrl); final Annotation annotation; if (displayLevel == HighlightDisplayLevel.ERROR) { annotation = holder.createErrorAnnotation(range, message); } else if (displayLevel == HighlightDisplayLevel.WARNING) { annotation = holder.createWarningAnnotation(range, message); } else if (displayLevel == HighlightDisplayLevel.WEAK_WARNING) { annotation = holder.createInfoAnnotation(range, message); } else { annotation = holder.createWarningAnnotation(range, message); } for (IntentionAction action : getQuickFixes()) { annotation.registerFix(action); } } } } } @NotNull protected abstract String getErrorMessage(@NotNull String url); @NotNull protected IntentionAction[] getQuickFixes() { return IntentionAction.EMPTY_ARRAY; } @NotNull protected abstract HighlightDisplayLevel getHighlightDisplayLevel(@NotNull PsiElement context); @NotNull private MyFetchResult checkUrl(String url) { synchronized (myFetchCacheLock) { final MyFetchCacheEntry entry = myFetchCache.get(url); final long currentTime = System.currentTimeMillis(); if (entry != null && currentTime - entry.getTime() < FETCH_CACHE_TIMEOUT) { return entry.getFetchResult(); } final MyFetchResult fetchResult = doCheckUrl(url); myFetchCache.put(url, new MyFetchCacheEntry(currentTime, fetchResult)); return fetchResult; } } private static MyFetchResult doCheckUrl(String url) { final HttpClient client = new HttpClient(); client.setTimeout(3000); client.setConnectionTimeout(3000); // see http://hc.apache.org/httpclient-3.x/cookies.html client.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY); try { final GetMethod method = new GetMethod(url); final int code = client.executeMethod(method); return code == HttpStatus.SC_OK || code == HttpStatus.SC_REQUEST_TIMEOUT ? MyFetchResult.OK : MyFetchResult.NONEXISTENCE; } catch (UnknownHostException e) { LOG.info(e); return MyFetchResult.UNKNOWN_HOST; } catch (IOException e) { LOG.info(e); return MyFetchResult.OK; } catch (IllegalArgumentException e) { LOG.debug(e); return MyFetchResult.OK; } } private static class MyFetchCacheEntry { private final long myTime; private final MyFetchResult myFetchResult; private MyFetchCacheEntry(long time, @NotNull MyFetchResult fetchResult) { myTime = time; myFetchResult = fetchResult; } public long getTime() { return myTime; } @NotNull public MyFetchResult getFetchResult() { return myFetchResult; } } private static enum MyFetchResult { OK, UNKNOWN_HOST, NONEXISTENCE } protected static class MyInfo { final PsiAnchor myAnchor; final String myUrl; final TextRange myRangeInElement; volatile boolean myResult; private MyInfo(PsiAnchor anchor, TextRange rangeInElement, String url) { myAnchor = anchor; myRangeInElement = rangeInElement; myUrl = url; } } }