/*
* Copyright 2002-2010 the original author or authors.
*
* 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.revolsys.util;
import java.io.Serializable;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.springframework.util.Assert;
import org.springframework.web.util.UriUtils;
/**
* Represents a URI template. A URI template is a URI-like String that contains variables enclosed
* by braces (<code>{</code>, <code>}</code>), which can be expanded to produce an actual URI.
*
* <p>See {@link #expand(Map)}, {@link #expand(Object[])}, and {@link #match(String)} for example usages.
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
* @see <a href="http://bitworking.org/projects/URI-Templates/">URI Templates</a>
*/
public class UriTemplate implements Serializable {
/**
* Static inner class to parse URI template strings into a matching regular expression.
*/
private static class Parser {
private final StringBuilder patternBuilder = new StringBuilder();
private final List<String> variableNames = new LinkedList<>();
private Parser(final String uriTemplate) {
Assert.hasText(uriTemplate, "'uriTemplate' must not be null");
final Matcher m = NAMES_PATTERN.matcher(uriTemplate);
int end = 0;
while (m.find()) {
this.patternBuilder.append(quote(uriTemplate, end, m.start()));
this.patternBuilder.append(VALUE_REGEX);
this.variableNames.add(m.group(1));
end = m.end();
}
this.patternBuilder.append(quote(uriTemplate, end, uriTemplate.length()));
final int lastIdx = this.patternBuilder.length() - 1;
if (lastIdx >= 0 && this.patternBuilder.charAt(lastIdx) == '/') {
this.patternBuilder.deleteCharAt(lastIdx);
}
}
private Pattern getMatchPattern() {
return Pattern.compile(this.patternBuilder.toString());
}
private List<String> getVariableNames() {
return Collections.unmodifiableList(this.variableNames);
}
private String quote(final String fullPath, final int start, final int end) {
if (start == end) {
return "";
}
return Pattern.quote(fullPath.substring(start, end));
}
}
/** Captures URI template variable names. */
private static final Pattern NAMES_PATTERN = Pattern.compile("\\{([^/]+?)\\}");
/**
*
*/
private static final long serialVersionUID = 1L;
/** Replaces template variables in the URI template. */
private static final String VALUE_REGEX = "(.*)";
private final Pattern matchPattern;
private final String uriTemplate;
private final List<String> variableNames;
/**
* Construct a new {@link UriTemplate} with the given URI String.
* @param uriTemplate the URI template string
*/
public UriTemplate(final String uriTemplate) {
final Parser parser = new Parser(uriTemplate);
this.uriTemplate = uriTemplate;
this.variableNames = parser.getVariableNames();
this.matchPattern = parser.getMatchPattern();
}
/**
* Encodes the given String as URL.
* <p>Defaults to {@link UriUtils#encodeUri(String, String)}.
* @param uri the URI to encode
* @return the encoded URI
*/
protected URI encodeUri(final String uri) {
try {
return new URI(uri);
} catch (final URISyntaxException ex) {
throw new IllegalArgumentException("Could not create URI from [" + uri + "]: " + ex, ex);
}
}
/**
* Given the Map of variables, expands this template into a URI. The Map keys represent variable names,
* the Map values variable values. The order of variables is not significant.
* <p>Example:
* <pre class="code">
* UriTemplate template = new UriTemplate("http://example.com/hotels/{hotel}/bookings/{booking}");
* Map<String, String> uriVariables = new HashMap<String, String>();
* uriVariables.put("booking", "42");
* uriVariables.put("hotel", "1");
* System.out.println(template.expand(uriVariables));
* </pre>
* will print: <blockquote><code>http://example.com/hotels/1/bookings/42</code></blockquote>
* @param uriVariables the map of URI variables
* @return the expanded URI
* @throws IllegalArgumentException if <code>uriVariables</code> is <code>null</code>;
* or if it does not contain values for all the variable names
*/
public URI expand(final Map<String, ?> uriVariables) {
Assert.notNull(uriVariables, "'uriVariables' must not be null");
final Object[] values = new Object[this.variableNames.size()];
for (int i = 0; i < this.variableNames.size(); i++) {
final String name = this.variableNames.get(i);
if (!uriVariables.containsKey(name)) {
throw new IllegalArgumentException("'uriVariables' Map has no value for '" + name + "'");
}
values[i] = uriVariables.get(name);
}
return expand(values);
}
/**
* Given an array of variables, expand this template into a full URI. The array represent variable values.
* The order of variables is significant.
* <p>Example:
* <pre class="code">
* UriTemplate template = new UriTemplate("http://example.com/hotels/{hotel}/bookings/{booking}");
* System.out.println(template.expand("1", "42));
* </pre>
* will print: <blockquote><code>http://example.com/hotels/1/bookings/42</code></blockquote>
* @param uriVariableValues the array of URI variables
* @return the expanded URI
* @throws IllegalArgumentException if <code>uriVariables</code> is <code>null</code>
* or if it does not contain sufficient variables
*/
public URI expand(final Object... uriVariableValues) {
Assert.notNull(uriVariableValues, "'uriVariableValues' must not be null");
if (uriVariableValues.length != this.variableNames.size()) {
throw new IllegalArgumentException(
"Invalid amount of variables values in [" + this.uriTemplate + "]: expected "
+ this.variableNames.size() + "; got " + uriVariableValues.length);
}
final Matcher matcher = NAMES_PATTERN.matcher(this.uriTemplate);
final StringBuffer buffer = new StringBuffer();
int i = 0;
while (matcher.find()) {
final Object uriVariable = uriVariableValues[i++];
final String replacement = Matcher
.quoteReplacement(uriVariable != null ? uriVariable.toString() : "");
matcher.appendReplacement(buffer, replacement);
}
matcher.appendTail(buffer);
return encodeUri(buffer.toString());
}
public String expandString(final Map<String, ?> uriVariables) {
Assert.notNull(uriVariables, "'uriVariables' must not be null");
final Object[] values = new Object[this.variableNames.size()];
for (int i = 0; i < this.variableNames.size(); i++) {
final String name = this.variableNames.get(i);
if (!uriVariables.containsKey(name)) {
throw new IllegalArgumentException("'uriVariables' Map has no value for '" + name + "'");
}
values[i] = uriVariables.get(name);
}
return expandString(values);
}
public String expandString(final Object... uriVariableValues) {
Assert.notNull(uriVariableValues, "'uriVariableValues' must not be null");
if (uriVariableValues.length != this.variableNames.size()) {
throw new IllegalArgumentException(
"Invalid amount of variables values in [" + this.uriTemplate + "]: expected "
+ this.variableNames.size() + "; got " + uriVariableValues.length);
}
final Matcher matcher = NAMES_PATTERN.matcher(this.uriTemplate);
final StringBuffer buffer = new StringBuffer();
int i = 0;
while (matcher.find()) {
final Object uriVariable = uriVariableValues[i++];
final String replacement = Matcher
.quoteReplacement(uriVariable != null ? uriVariable.toString() : "");
matcher.appendReplacement(buffer, replacement);
}
matcher.appendTail(buffer);
return buffer.toString();
}
/**
* Return the names of the variables in the template, in order.
* @return the template variable names
*/
public List<String> getVariableNames() {
return this.variableNames;
}
/**
* Match the given URI to a map of variable values. Keys in the returned map are variable names,
* values are variable values, as occurred in the given URI.
* <p>Example:
* <pre class="code">
* UriTemplate template = new UriTemplate("http://example.com/hotels/{hotel}/bookings/{booking}");
* System.out.println(template.match("http://example.com/hotels/1/bookings/42"));
* </pre>
* will print: <blockquote><code>{hotel=1, booking=42}</code></blockquote>
* @param uri the URI to match to
* @return a map of variable values
*/
public Map<String, String> match(final String uri) {
Assert.notNull(uri, "'uri' must not be null");
final Map<String, String> result = new LinkedHashMap<>(this.variableNames.size());
final Matcher matcher = this.matchPattern.matcher(uri);
if (matcher.find()) {
for (int i = 1; i <= matcher.groupCount(); i++) {
final String name = this.variableNames.get(i - 1);
final String value = matcher.group(i);
result.put(name, value);
}
}
return result;
}
/**
* Indicate whether the given URI matches this template.
* @param uri the URI to match to
* @return <code>true</code> if it matches; <code>false</code> otherwise
*/
public boolean matches(final String uri) {
if (uri == null) {
return false;
}
final Matcher matcher = this.matchPattern.matcher(uri);
return matcher.matches();
}
@Override
public String toString() {
return this.uriTemplate;
}
}