com.flipkart.poseidon.handlers.http.utils.StringUtils.java Source code

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Here is the source code for com.flipkart.poseidon.handlers.http.utils.StringUtils.java

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/*
 * Copyright 2015 Flipkart Internet, pvt ltd.
 *
 * 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.flipkart.poseidon.handlers.http.utils;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.NullArgumentException;

import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class StringUtils {

    /**
     * Returns false if given string in null or empty
     */
    public static boolean isNullOrEmpty(String string) {
        if (string != null) {
            return string.isEmpty();
        }
        return true;
    }

    /**
     *  Joins the array of values with a given separator and returns the .
     */
    public static String join(String[] arrayOfStrings, String separator) {
        boolean appendSeparator = false;
        if (arrayOfStrings != null) {
            StringBuilder stringBuilder = new StringBuilder();
            for (String string : arrayOfStrings) {
                if (appendSeparator) {
                    stringBuilder.append(separator);
                } else {
                    appendSeparator = true;
                }
                stringBuilder.append(string);
            }
            return stringBuilder.toString();
        } else {
            throw new NullArgumentException("arrayOfStrings");
        }
    }

    /**
     * always encode in UTF8. does NOT close your input stream. client need to close it.
     * @param inputStream
     * @return String encoded using UTF-8 scheme.
     * @throws Exception, any exception encountered. Will not check for any null condition.
     */
    public static String inputStream2String(InputStream inputStream) throws Exception {
        StringWriter writer = new StringWriter();
        IOUtils.copy(inputStream, writer, "UTF-8");
        String theString = writer.toString();
        return theString;
    }

    /**
     * Gets the query parameters from the URL
     * @param httpUrl The URL from which query params have to be extracted
     * @return 
     */
    public static Map<String, String> getQueryParams(String httpUrl) {
        Map<String, String> params = new HashMap<String, String>();
        if (httpUrl == null) {
            return params;
        }

        URL url = null;
        try {
            url = new URL(httpUrl);
        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }

        String query = url.getQuery();
        if (query == null) {
            return params;
        }

        StringTokenizer tokenizer = new StringTokenizer(query, "&");
        while (tokenizer.hasMoreTokens()) {
            String token = tokenizer.nextToken();
            int index = token.indexOf("=");
            params.put(token.substring(0, index).trim(), token.substring(index + 1).trim());
        }

        return params;
    }

    public static String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();
        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append((line + "\n"));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}