com.github.sdorra.webresources.WebResources Maven / Gradle / Ivy
/**
* The MIT License
* Copyright (c) 2018 Sebastian Sdorra
*
* 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 com.github.sdorra.webresources;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Instant;
import java.util.Optional;
/**
* {@link WebResources} provides util methods to create {@link WebResource}.
*/
public final class WebResources {
private WebResources(){}
/**
* Creates a {@link WebResource} from a {@link URL}, if the url is a file url {@link #of(Path)} is internally used.
* Warning: This method should not be used with an external url.
*
* @param url source url
*
* @return web resource
*
* @throws IOException if web resource could not be created
*/
public static WebResource of(URL url) throws IOException {
if ("file".equals(url.getProtocol())) {
try {
return of(Paths.get(url.toURI()));
} catch (URISyntaxException ex) {
throw new IOException("failed to get path from uri", ex);
}
}
URLConnection connection = url.openConnection();
String name = name(url);
long size = connection.getContentLengthLong();
long lastModified = connection.getLastModified();
return builder(name, () -> url.openConnection().getInputStream())
.withContentLength(size)
.withLastModifiedDate(lastModified)
.withContentType(ContentTypeResolver.resolve(url.getPath()))
.withETag(etag(name, size, lastModified))
.build();
}
private static String name(URL url) {
String path = url.getPath();
int index = path.lastIndexOf('/');
if (index > 0) {
return path.substring(index + 1);
}
return path;
}
/**
* Creates a {@link WebResource} from a file.
*
* @param file source file
*
* @return web resource
*
* @throws IOException if web resource could not be created
*/
public static WebResource of(File file) throws IOException {
return of(file.toPath());
}
/**
* Creates a {@link WebResource} from a path.
*
* @param path source path
*
* @return web resource
*
* @throws IOException if web resource could not be created
*/
public static WebResource of(Path path) throws IOException {
String name = path.getFileName().toString();
return builder(name, () -> Files.newInputStream(path))
.withContentLength(Files.size(path))
.withLastModifiedDate(Files.getLastModifiedTime(path).toInstant())
.withContentType(ContentTypeResolver.resolve(path.toString()))
.withETag(etag(path))
.build();
}
/**
* Creates builder for a {@link WebResource}.
*
* @param name name of the resource
* @param contentThrowingSupplier content provider
*
* @return web resource builder
*/
public static Builder builder(String name, ThrowingSupplier contentThrowingSupplier) {
return new Builder(name, contentThrowingSupplier);
}
/**
* Creates an etag from the given file path.
* Note: This method is only visible for testing
*
* @param path file path
*
* @return etag
*
* @throws IOException If an input or output exception occurs
*/
static String etag(Path path) throws IOException {
String name = path.getFileName().toString();
long size = Files.size(path);
long lastModified = Files.getLastModifiedTime(path).toMillis();
return etag(name, size, lastModified);
}
private static String etag(String name, long size, long lastModifid) {
return String.format("%s_%s_%s", name, size, lastModifid);
}
/**
* Web resource builder.
*/
public static class Builder {
private final WebResourceImpl resource;
private Builder(String name, ThrowingSupplier contentSupplier) {
this.resource = new WebResourceImpl(name, contentSupplier);
}
/**
* Sets length of web resource content.
*
* @param length content length
*
* @return {@code this}
*/
public Builder withContentLength(Long length) {
if (length != null && length >= 0) {
resource.contentLength = length;
}
return this;
}
/**
* Sets the content type of the web resource.
*
* @param contentType content type
*
* @return {@code this}
*/
public Builder withContentType(String contentType) {
resource.contentType = contentType;
return this;
}
/**
* Sets the etag of the web resource.
*
* @param etag etag of resource
*
* @return {@code this}
*/
public Builder withETag(String etag) {
resource.etag = etag;
return this;
}
/**
* Sets the last modified date of the web resource.
*
* @param lastModifiedDate in milliseconds
*
* @return {@code this}
*/
public Builder withLastModifiedDate(long lastModifiedDate) {
if (lastModifiedDate != -1) {
resource.lastModifiedDate = Instant.ofEpochMilli(lastModifiedDate);
}
return this;
}
/**
* Sets the last modified date of the web resource.
*
* @param lastModifiedDate last modified date
*
* @return {@code this}
*/
public Builder withLastModifiedDate(Instant lastModifiedDate) {
resource.lastModifiedDate = lastModifiedDate;
return this;
}
/**
* Creates web resource.
*
* @return web resource
*/
public WebResource build() {
return resource;
}
}
private static class WebResourceImpl implements WebResource {
private final String name;
private final ThrowingSupplier contentSupplier;
private Long contentLength;
private String contentType;
private String etag;
private Instant lastModifiedDate;
private WebResourceImpl(String name, ThrowingSupplier contentSupplier) {
this.name = name;
this.contentSupplier = contentSupplier;
}
@Override
public String getName() {
return name;
}
@Override
public InputStream getContent() throws IOException {
return contentSupplier.get();
}
@Override
public Optional getContentLength() {
return Optional.ofNullable(contentLength);
}
@Override
public Optional getContentType() {
return Optional.ofNullable(contentType);
}
@Override
public Optional getETag() {
return Optional.ofNullable(etag);
}
@Override
public Optional getLastModifiedDate() {
return Optional.ofNullable(lastModifiedDate);
}
}
}
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