Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Copyright (C) 2020 Graylog, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* .
*/
package org.graylog2.lookup.adapters.dsvhttp;
import com.google.common.collect.ImmutableMap;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import javax.inject.Inject;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicReference;
public class HTTPFileRetriever {
private final AtomicReference> lastLastModified = new AtomicReference<>(Collections.emptyMap());
private final OkHttpClient client;
@Inject
public HTTPFileRetriever(OkHttpClient httpClient) {
this.client = httpClient.newBuilder()
.followRedirects(true)
.followSslRedirects(true)
.build();
}
/**
* Request file. No "If-Modified-Since" header will be sent so the file will be fetched again, even if hasn't been
* modified since the last fetch.
*/
public Optional fetchFile(String url) throws IOException {
return fetchFile(url, false);
}
/**
* Request file bytes. No "If-Modified-Since" header will be sent so the file will be fetched again, even if hasn't
* been modified since the last fetch.
*/
public Optional fetchFileBytes(String url) throws IOException {
return fetchFileBytes(url, false);
}
/**
* Request that a file be downloaded and stored to the provided location. No "If-Modified-Since" header will be
* sent so the file will be fetched again, even if it hasn't been modified since the last fetch.
*/
public boolean downloadFile(String url, Path toPath) throws IOException {
return downloadFile(url, toPath, false);
}
/**
* Request file by sending an "If-Modified-Since" header so that the file won't be fetched if it hasn't been
* modified since the last request.
*/
public Optional fetchFileIfNotModified(String url) throws IOException {
return fetchFile(url, true);
}
/**
* Request file bytes by sending an "If-Modified-Since" header so that the file won't be fetched if it hasn't been
* modified since the last request.
*/
public Optional fetchFileBytesIfNotModified(String url) throws IOException {
return fetchFileBytes(url, true);
}
/**
* Request that a file be downloaded and stored to the provided location. Will send the "If-Modified-Since" header
* so that the file won't be fetched if it hasn't been modified since the last request. Returns TRUE if the file
* was downloaded, FALSE otherwise.
*/
public boolean downloadFileIfNotModified(String url, Path toPath) throws IOException {
return downloadFile(url, toPath, true);
}
private boolean downloadFile(String url, Path toPath, boolean addIfModifiedSinceHeader) throws IOException {
try (Response response = doHttpGet(url, addIfModifiedSinceHeader)) {
if (null != response && null != response.body()) {
Files.copy(response.body().byteStream(), toPath, StandardCopyOption.REPLACE_EXISTING);
return true;
}
return false;
}
}
private Optional fetchFileBytes(String url, boolean addIfModifiedSinceHeader) throws IOException {
try (Response response = doHttpGet(url, addIfModifiedSinceHeader)) {
if (null != response && null != response.body()) {
return Optional.of(response.body().bytes());
}
}
return Optional.empty();
}
private Optional fetchFile(String url, boolean addIfModifiedSinceHeader) throws IOException {
try (Response response = doHttpGet(url, addIfModifiedSinceHeader)) {
if (null != response && null != response.body()) {
return Optional.of(response.body().string());
}
}
return Optional.empty();
}
private Response doHttpGet(String url, boolean addIfModifiedSinceHeader) throws IOException {
final Request.Builder requestBuilder = new Request.Builder()
.get()
.url(url)
.header("User-Agent", "Graylog (server)");
if (addIfModifiedSinceHeader) {
final String lastModified = this.lastLastModified.get().get(url);
if (lastModified != null) {
requestBuilder.header("If-Modified-Since", lastModified);
}
}
final Call request = client.newCall(requestBuilder.build());
final Response response = request.execute();
if (response.isSuccessful()) {
final String lastModifiedHeader = response.header("Last-Modified", DateTime.now(DateTimeZone.UTC).toString());
final Map newLastModified = new HashMap<>(this.lastLastModified.get());
newLastModified.put(url, lastModifiedHeader);
this.lastLastModified.set(ImmutableMap.copyOf(newLastModified));
return response;
} else {
response.close();
if (response.code() != 304) {
throw new IOException("Request failed: " + response.message());
}
}
return null;
}
}
