co.jirm.core.util.JirmUrlEncodedUtils.java Source code

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Here is the source code for co.jirm.core.util.JirmUrlEncodedUtils.java

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/**
 * Copyright (C) 2012 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 co.jirm.core.util;

import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;

public class JirmUrlEncodedUtils {

    private static final String PARAMETER_SEPARATOR = "&";
    private static final String NAME_VALUE_SEPARATOR = "=";

    /**
     * Returns a list of {@link NameValuePair NameValuePairs} as built from the
     * URI's query portion. For example, a URI of
     * http://example.org/path/to/file?a=1&b=2&c=3 would return a list of three
     * NameValuePairs, one for a=1, one for b=2, and one for c=3.
     * <p>
     * This is typically useful while parsing an HTTP PUT.
     *
     * @param uri
     *            uri to parse
     * @param encoding
     *            encoding to use while parsing the query
     */
    public static List<NameValuePair> parse(final URI uri, final String encoding) {
        List<NameValuePair> result = Collections.emptyList();
        final String query = uri.getRawQuery();
        if (query != null && query.length() > 0) {
            result = new ArrayList<NameValuePair>();
            parse(result, new Scanner(query), encoding);
        }
        return result;
    }

    public static Map<String, List<String>> parseParameters(final URI uri, final String encoding) {
        List<NameValuePair> result = parse(uri, encoding);
        Map<String, List<String>> m = Maps.newLinkedHashMap();
        for (NameValuePair nvp : result) {
            List<String> list = m.get(nvp.getName());
            if (list == null) {
                list = Lists.newArrayList();
                m.put(nvp.getName(), list);
            }
            list.add(nvp.getValue());
        }
        return m;
    }

    /**
     * Adds all parameters within the Scanner to the list of
     * <code>parameters</code>, as encoded by <code>encoding</code>. For
     * example, a scanner containing the string <code>a=1&b=2&c=3</code> would
     * add the {@link NameValuePair NameValuePairs} a=1, b=2, and c=3 to the
     * list of parameters.
     *
     * @param parameters
     *            List to add parameters to.
     * @param scanner
     *            Input that contains the parameters to parse.
     * @param encoding
     *            Encoding to use when decoding the parameters.
     */
    public static void parse(final List<NameValuePair> parameters, final Scanner scanner, final String encoding) {
        scanner.useDelimiter(PARAMETER_SEPARATOR);
        while (scanner.hasNext()) {
            final String[] nameValue = scanner.next().split(NAME_VALUE_SEPARATOR);
            if (nameValue.length == 0 || nameValue.length > 2)
                throw new IllegalArgumentException("bad parameter");

            final String name = decode(nameValue[0], encoding);
            String value = null;
            if (nameValue.length == 2)
                value = decode(nameValue[1], encoding);
            parameters.add(new NameValuePair(name, value));
        }
    }

    public static class NameValuePair {
        private final String name;
        private final String value;

        private NameValuePair(String name, String value) {
            super();
            this.name = name;
            this.value = value;
        }

        public String getName() {
            return name;
        }

        public String getValue() {
            return value;
        }

    }

    /**
     * Returns a String that is suitable for use as an <code>application/x-www-form-urlencoded</code>
     * list of parameters in an HTTP PUT or HTTP POST.
     *
     * @param parameters  The parameters to include.
     * @param encoding The encoding to use.
     */
    public static String format(final List<? extends NameValuePair> parameters, final String encoding) {
        final StringBuilder result = new StringBuilder();
        for (final NameValuePair parameter : parameters) {
            final String encodedName = encode(parameter.getName(), encoding);
            final String value = parameter.getValue();
            final String encodedValue = value != null ? encode(value, encoding) : "";
            if (result.length() > 0)
                result.append(PARAMETER_SEPARATOR);
            result.append(encodedName);
            result.append(NAME_VALUE_SEPARATOR);
            result.append(encodedValue);
        }
        return result.toString();
    }

    private static String decode(final String content, final String encoding) {
        try {
            return URLDecoder.decode(content, encoding != null ? encoding : "UTF-8");
        } catch (UnsupportedEncodingException problem) {
            throw new IllegalArgumentException(problem);
        }
    }

    private static String encode(final String content, final String encoding) {
        try {
            return URLEncoder.encode(content, encoding != null ? encoding : "UTF-8");
        } catch (UnsupportedEncodingException problem) {
            throw new IllegalArgumentException(problem);
        }
    }
}