URIBuilder.java

/*
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package com.gistlabs.mechanize.util.apache;

import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.http.NameValuePair;
import org.apache.http.annotation.NotThreadSafe;
import org.apache.http.conn.util.InetAddressUtils;
import org.apache.http.message.BasicNameValuePair;

/**
 * {@link URI} builder for HTTP requests.
 *
 * @since 4.2
 */
@NotThreadSafe
public class URIBuilder {

	private String scheme;
	private String encodedSchemeSpecificPart;
	private String encodedAuthority;
	private String userInfo;
	private String encodedUserInfo;
	private String host;
	private int port;
	private String path;
	private String encodedPath;
	private String encodedQuery;
	private List<NameValuePair> queryParams;
	private String fragment;
	private String encodedFragment;

	/**
	 * Constructs an empty instance.
	 */
	public URIBuilder() {
		super();
		this.port = -1;
	}

	/**
	 * Construct an instance from the string which must be a valid URI.
	 * 
	 * @param string a valid URI in string form
	 * @throws URISyntaxException if the input is not a valid URI
	 */
	public URIBuilder(final String string) throws URISyntaxException {
		super();
		digestURI(new URI(string));
	}

	/**
	 * Construct an instance from the provided URI.
	 * @param uri
	 */
	public URIBuilder(final URI uri) {
		super();
		digestURI(uri);
	}

	private List <NameValuePair> parseQuery(final String query, final Charset charset) {
		if (query != null && query.length() > 0)
			return URLEncodedUtils.parse(query, charset);
		return null;
	}

	/**
	 * Builds a {@link URI} instance.
	 */
	public URI build() throws URISyntaxException {
		return new URI(buildString());
	}

	private String buildString() {
		StringBuilder sb = new StringBuilder();
		if (this.scheme != null)
			sb.append(this.scheme).append(':');
		if (this.encodedSchemeSpecificPart != null)
			sb.append(this.encodedSchemeSpecificPart);
		else {
			if (this.encodedAuthority != null)
				sb.append("//").append(this.encodedAuthority);
			else if (this.host != null) {
				sb.append("//");
				if (this.encodedUserInfo != null)
					sb.append(this.encodedUserInfo).append("@");
				else if (this.userInfo != null)
					sb.append(encodeUserInfo(this.userInfo)).append("@");
				if (InetAddressUtils.isIPv6Address(this.host))
					sb.append("[").append(this.host).append("]");
				else
					sb.append(this.host);
				if (this.port >= 0)
					sb.append(":").append(this.port);
			}
			if (this.encodedPath != null)
				sb.append(normalizePath(this.encodedPath));
			else if (this.path != null)
				sb.append(encodePath(normalizePath(this.path)));
			if (this.encodedQuery != null)
				sb.append("?").append(this.encodedQuery);
			else if (this.queryParams != null)
				sb.append("?").append(encodeQuery(this.queryParams));
		}
		if (this.encodedFragment != null)
			sb.append("#").append(this.encodedFragment);
		else if (this.fragment != null)
			sb.append("#").append(encodeFragment(this.fragment));
		return sb.toString();
	}

	private void digestURI(final URI uri) {
		this.scheme = uri.getScheme();
		this.encodedSchemeSpecificPart = uri.getRawSchemeSpecificPart();
		this.encodedAuthority = uri.getRawAuthority();
		this.host = uri.getHost();
		this.port = uri.getPort();
		this.encodedUserInfo = uri.getRawUserInfo();
		this.userInfo = uri.getUserInfo();
		this.encodedPath = uri.getRawPath();
		this.path = uri.getPath();
		this.encodedQuery = uri.getRawQuery();
		this.queryParams = parseQuery(uri.getRawQuery(), Consts.UTF_8);
		this.encodedFragment = uri.getRawFragment();
		this.fragment = uri.getFragment();
	}

	private String encodeUserInfo(final String userInfo) {
		return URLEncodedUtils.encUserInfo(userInfo, Consts.UTF_8);
	}

	private String encodePath(final String path) {
		return URLEncodedUtils.encPath(path, Consts.UTF_8);
	}

	private String encodeQuery(final List<NameValuePair> params) {
		return URLEncodedUtils.format(params, Consts.UTF_8);
	}

	private String encodeFragment(final String fragment) {
		return URLEncodedUtils.encFragment(fragment, Consts.UTF_8);
	}

	/**
	 * Sets URI scheme.
	 */
	 public URIBuilder setScheme(final String scheme) {
		 this.scheme = scheme;
		 return this;
	 }

	 /**
	  * Sets URI user info. The value is expected to be unescaped and may contain non ASCII
	  * characters.
	  */
	 public URIBuilder setUserInfo(final String userInfo) {
		 this.userInfo = userInfo;
		 this.encodedSchemeSpecificPart = null;
		 this.encodedAuthority = null;
		 this.encodedUserInfo = null;
		 return this;
	 }

	 /**
	  * Sets URI user info as a combination of username and password. These values are expected to
	  * be unescaped and may contain non ASCII characters.
	  */
	 public URIBuilder setUserInfo(final String username, final String password) {
		 return setUserInfo(username + ':' + password);
	 }

	 /**
	  * Sets URI host.
	  */
	 public URIBuilder setHost(final String host) {
		 this.host = host;
		 this.encodedSchemeSpecificPart = null;
		 this.encodedAuthority = null;
		 return this;
	 }

	 /**
	  * Sets URI port.
	  */
	 public URIBuilder setPort(final int port) {
		 this.port = port < 0 ? -1 : port;
		 this.encodedSchemeSpecificPart = null;
		 this.encodedAuthority = null;
		 return this;
	 }

	 /**
	  * Sets URI path. The value is expected to be unescaped and may contain non ASCII characters.
	  */
	 public URIBuilder setPath(final String path) {
		 this.path = path;
		 this.encodedSchemeSpecificPart = null;
		 this.encodedPath = null;
		 return this;
	 }

	 /**
	  * Removes URI query.
	  */
	 public URIBuilder removeQuery() {
		 this.queryParams = null;
		 this.encodedQuery = null;
		 this.encodedSchemeSpecificPart = null;
		 return this;
	 }

	 /**
	  * Sets URI query.
	  * <p>
	  * The value is expected to be encoded form data.
	  */
	 public URIBuilder setQuery(final String query) {
		 this.queryParams = parseQuery(query, Consts.UTF_8);
		 this.encodedQuery = null;
		 this.encodedSchemeSpecificPart = null;
		 return this;
	 }

	 /**
	  * Adds parameter to URI query. The parameter name and value are expected to be unescaped
	  * and may contain non ASCII characters.
	  */
	 public URIBuilder addParameter(final String param, final String value) {
		 if (this.queryParams == null)
			 this.queryParams = new ArrayList<NameValuePair>();
		 this.queryParams.add(new BasicNameValuePair(param, value));
		 this.encodedQuery = null;
		 this.encodedSchemeSpecificPart = null;
		 return this;
	 }

	 /**
	  * Sets parameter of URI query overriding existing value if set. The parameter name and value
	  * are expected to be unescaped and may contain non ASCII characters.
	  */
	 public URIBuilder setParameter(final String param, final String value) {
		 if (this.queryParams == null)
			 this.queryParams = new ArrayList<NameValuePair>();
		 if (!this.queryParams.isEmpty())
			 for (Iterator<NameValuePair> it = this.queryParams.iterator(); it.hasNext(); ) {
				 NameValuePair nvp = it.next();
				 if (nvp.getName().equals(param))
					 it.remove();
			 }
		 this.queryParams.add(new BasicNameValuePair(param, value));
		 this.encodedQuery = null;
		 this.encodedSchemeSpecificPart = null;
		 return this;
	 }

	 /**
	  * Sets URI fragment. The value is expected to be unescaped and may contain non ASCII
	  * characters.
	  */
	 public URIBuilder setFragment(final String fragment) {
		 this.fragment = fragment;
		 this.encodedFragment = null;
		 return this;
	 }

	 public String getScheme() {
		 return this.scheme;
	 }

	 public String getUserInfo() {
		 return this.userInfo;
	 }

	 public String getHost() {
		 return this.host;
	 }

	 public int getPort() {
		 return this.port;
	 }

	 public String getPath() {
		 return this.path;
	 }

	 public List<NameValuePair> getQueryParams() {
		 if (this.queryParams != null)
			 return new ArrayList<NameValuePair>(this.queryParams);
		 else
			 return new ArrayList<NameValuePair>();
	 }

	 public String getFragment() {
		 return this.fragment;
	 }

	 @Override
	 public String toString() {
		 return buildString();
	 }

	 private static String normalizePath(String path) {
		 if (path == null)
			 return null;
		 int n = 0;
		 for (; n < path.length(); n++)
			 if (path.charAt(n) != '/')
				 break;
		 if (n > 1)
			 path = path.substring(n - 1);
		 return path;
	 }

}