/*
* Copyright 2014-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.amazonaws.services.s3;
import java.net.URI;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* A URI wrapper that can parse out information about an S3 URI.
*/
public class AmazonS3URI {
private static final Pattern ENDPOINT_PATTERN =
Pattern.compile("^(.+\\.)?s3[.-]([a-z0-9-]+)\\.");
private final URI uri;
private final boolean isPathStyle;
private final String bucket;
private final String key;
private final String region;
/**
* Creates a new AmazonS3URI by parsing the given string.
*
* @param str the URI to parse.
*/
public AmazonS3URI(final String str) {
this(URI.create(str));
}
/**
* Creates a new AmazonS3URI by wrapping the given {@code URI}.
*
* @param uri the URI to wrap
*/
public AmazonS3URI(final URI uri) {
if (uri == null) {
throw new IllegalArgumentException("uri cannot be null");
}
this.uri = uri;
String host = uri.getHost();
if (host == null) {
throw new IllegalArgumentException("Invalid S3 URI: no hostname: "
+ uri);
}
Matcher matcher = ENDPOINT_PATTERN.matcher(host);
if (!matcher.find()) {
throw new IllegalArgumentException(
"Invalid S3 URI: hostname does not appear to be a valid S3 "
+ "endpoint: " + uri);
}
String prefix = matcher.group(1);
if (prefix == null || prefix.isEmpty()) {
// No bucket name in the authority; parse it from the path.
this.isPathStyle = true;
// Grab the encoded path so we don't run afoul of '/'s in the
// bucket name.
String path = uri.getRawPath();
if ("/".equals(path)) {
this.bucket = null;
this.key = null;
} else {
int index = path.indexOf('/', 1);
if (index == -1) {
// https://s3.amazonaws.com/bucket
this.bucket = decode(path.substring(1));
this.key = null;
} else if (index == (path.length() - 1)) {
// https://s3.amazonaws.com/bucket/
this.bucket = decode(path.substring(1, index));
this.key = null;
} else {
// https://s3.amazonaws.com/bucket/key
this.bucket = decode(path.substring(1, index));
this.key = decode(path.substring(index + 1));
}
}
} else {
// Bucket name was found in the host; path is the key.
this.isPathStyle = false;
// Remove the trailing '.' from the prefix to get the bucket.
this.bucket = prefix.substring(0, prefix.length() - 1);
if ("/".equals(uri.getPath())) {
this.key = null;
} else {
// Remove the leading '/'.
this.key = uri.getPath().substring(1);
}
}
if ("amazonaws".equals(matcher.group(2))) {
// No region specified
this.region = null;
} else {
this.region = matcher.group(2);
}
}
/**
* @return the S3 URI being parsed
*/
public URI getURI() {
return uri;
}
/**
* @return true if the URI contains the bucket in the path, false if it
* contains the bucket in the authority
*/
public boolean isPathStyle() {
return isPathStyle;
}
/**
* @return the bucket name parsed from the URI (or null if no bucket
* specified)
*/
public String getBucket() {
return bucket;
}
/**
* @return the key parsed from the URI (or null if no key specified)
*/
public String getKey() {
return key;
}
/**
* @return the region parsed from the URI (or null if no region specified)
*/
public String getRegion() {
return region;
}
@Override
public String toString() {
return uri.toString();
}
/**
* Percent-decodes the given string, with a fast path for strings that are
* not percent-encoded.
*
* @param str the string to decode
* @return the decoded string
*/
private static String decode(final String str) {
if (str == null) {
return null;
}
for (int i = 0; i < str.length(); ++i) {
if (str.charAt(i) == '%') {
return decode(str, i);
}
}
return str;
}
/**
* Percent-decodes the given string.
*
* @param str the string to decode
* @param firstPercent the index of the first '%' character in the string
* @return the decoded string
*/
private static String decode(final String str, final int firstPercent) {
StringBuilder builder = new StringBuilder();
builder.append(str.substring(0, firstPercent));
appendDecoded(builder, str, firstPercent);
for (int i = firstPercent + 3; i < str.length(); ++i) {
if (str.charAt(i) == '%') {
appendDecoded(builder, str, i);
i += 2;
} else {
builder.append(str.charAt(i));
}
}
return builder.toString();
}
/**
* Decodes the percent-encoded character at the given index in the string
* and appends the decoded value to the given {@code StringBuilder}.
*
* @param builder the string builder to append to
* @param str the string being decoded
* @param index the index of the '%' character in the string
*/
private static void appendDecoded(final StringBuilder builder,
final String str,
final int index) {
if (index > str.length() - 3) {
throw new IllegalStateException("Invalid percent-encoded string:"
+ "\"" + str + "\".");
}
char first = str.charAt(index + 1);
char second = str.charAt(index + 2);
char decoded = (char) ((fromHex(first) << 4) | fromHex(second));
builder.append(decoded);
}
/**
* Converts a hex character (0-9A-Fa-f) into its corresponding quad value.
*
* @param c the hex character
* @return the quad value
*/
private static int fromHex(final char c) {
if (c < '0') {
throw new IllegalStateException(
"Invalid percent-encoded string: bad character '" + c + "' in "
+ "escape sequence.");
}
if (c <= '9') {
return (c - '0');
}
if (c < 'A') {
throw new IllegalStateException(
"Invalid percent-encoded string: bad character '" + c + "' in "
+ "escape sequence.");
}
if (c <= 'F') {
return (c - 'A') + 10;
}
if (c < 'a') {
throw new IllegalStateException(
"Invalid percent-encoded string: bad character '" + c + "' in "
+ "escape sequence.");
}
if (c <= 'f') {
return (c - 'a') + 10;
}
throw new IllegalStateException(
"Invalid percent-encoded string: bad character '" + c + "' in "
+ "escape sequence.");
}
}