com.hp.hpl.jena.sparql.engine.http.Params.java Source code

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Here is the source code for com.hp.hpl.jena.sparql.engine.http.Params.java

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/*
 * 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.
 */

package com.hp.hpl.jena.sparql.engine.http;

import java.nio.charset.StandardCharsets;
import java.util.*;

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URLEncodedUtils;

/** A collection of parameters for protocol use. */

public class Params {
    // As seen.
    private List<Pair> paramList = new ArrayList<>();

    // string -> list -> string
    private Map<String, List<String>> params = new HashMap<>();

    /** Create a Params object */

    public Params() {
    }

    /** Create a Params object, initialized from another one.  A copy is made
     * so the initial values of the Params object are as of the time this constructor
     * was called.
     *  
     * @param other
     */
    public Params(Params other) {
        merge(other);
    }

    public void merge(Params other) {
        params.putAll(other.params);
        paramList.addAll(other.paramList);
    }

    /** Add a parameter.
     * @param name  Name of the parameter
     * @param value Value - May be null to indicate none - the name still goes.
     */

    public void addParam(String name, String value) {
        Pair p = new Pair(name, value);
        paramList.add(p);
        List<String> x = params.get(name);
        if (x == null) {
            x = new ArrayList<>();
            params.put(name, x);
        }
        x.add(value);
    }

    /** Valueless parameter */
    public void addParam(String name) {
        addParam(name, null);
    }

    public boolean containsParam(String name) {
        return params.containsKey(name);
    }

    public String getValue(String name) {
        List<String> x = getMV(name);
        if (x == null)
            return null;
        if (x.size() != 1)
            throw new MultiValueException("Multiple value (" + x.size() + " when exactly one requested");
        return x.get(0);
    }

    public List<String> getValues(String name) {
        return getMV(name);
    }

    public void remove(String name) {
        // Absolute record
        for (Iterator<Pair> iter = paramList.iterator(); iter.hasNext();) {
            Pair p = iter.next();
            if (p.getName().equals(name))
                iter.remove();
        }
        // Map
        params.remove(name);
    }

    /** Exactly as seen */
    public List<Pair> pairs() {
        return paramList;
    }

    public int count() {
        return paramList.size();
    }

    /** Get the names of parameters - one ocurrence */
    public List<String> names() {
        List<String> names = new ArrayList<>();
        for (Pair pair : paramList) {
            String s = pair.getName();
            if (names.contains(s))
                continue;
            names.add(s);
        }
        return names;
    }

    /** Query string, without leading "?" */
    public String httpString() {
        return URLEncodedUtils.format(paramList, StandardCharsets.UTF_8);
    }

    private List<String> getMV(String name) {
        return params.get(name);
    }

    static class MultiValueException extends RuntimeException {
        MultiValueException(String msg) {
            super(msg);
        }
    }

    public static class Pair implements NameValuePair {
        String name;
        String value;

        Pair(String name, String value) {
            setName(name);
            setValue(value);
        }

        @Override
        public String getName() {
            return name;
        }

        @Override
        public String getValue() {
            return value;
        }

        void setName(String name) {
            this.name = name;
        }

        void setValue(String value) {
            this.value = value;
        }

    }
}