HttpUtils.java

/**
 * Copyright 2016 benjobs
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 org.opencron.common.utils;


import java.io.*;
import java.net.*;
import java.util.Random;

/**
 * Created by benjobs on 15/9/30.
 */
public abstract class HttpUtils {

    public static String doGet(String url, String charset) throws Exception {
        AssertUtils.notNull(url);

        URL localURL = new URL(url);
        URLConnection connection = localURL.openConnection();
        HttpURLConnection httpURLConnection = (HttpURLConnection) connection;

        httpURLConnection.setRequestProperty("Accept-Charset", charset);
        httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

        InputStream inputStream = null;
        InputStreamReader inputStreamReader = null;
        BufferedReader reader = null;
        StringBuffer resultBuffer = new StringBuffer();
        String tempLine = null;

        if (httpURLConnection.getResponseCode() >= 300) {
            throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
        }

        try {
            inputStream = httpURLConnection.getInputStream();
            inputStreamReader = new InputStreamReader(inputStream, charset);
            reader = new BufferedReader(inputStreamReader);

            while ((tempLine = reader.readLine()) != null) {
                resultBuffer.append(tempLine).append("\n");
            }

        } finally {

            if (reader != null) {
                reader.close();
            }

            if (inputStreamReader != null) {
                inputStreamReader.close();
            }

            if (inputStream != null) {
                inputStream.close();
            }

        }

        return resultBuffer.toString();
    }


    public static String doPost(String url, String parameterData, String charset) throws Exception {

        AssertUtils.notNull(url);

        URL localURL = new URL(url);
        URLConnection connection = localURL.openConnection();
        HttpURLConnection httpURLConnection = (HttpURLConnection) connection;

        httpURLConnection.setDoOutput(true);
        httpURLConnection.setRequestMethod("POST");
        httpURLConnection.setRequestProperty("Accept-Charset", charset);
        httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        httpURLConnection.setRequestProperty("Content-Length", String.valueOf(parameterData.length()));

        OutputStream outputStream = null;
        OutputStreamWriter outputStreamWriter = null;
        InputStream inputStream = null;
        InputStreamReader inputStreamReader = null;
        BufferedReader reader = null;
        StringBuffer resultBuffer = new StringBuffer();
        String tempLine = null;

        try {
            outputStream = httpURLConnection.getOutputStream();
            outputStreamWriter = new OutputStreamWriter(outputStream, charset);

            outputStreamWriter.write(parameterData.toString());
            outputStreamWriter.flush();

            if (httpURLConnection.getResponseCode() >= 300) {
                throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
            }

            inputStream = httpURLConnection.getInputStream();
            inputStreamReader = new InputStreamReader(inputStream, charset);
            reader = new BufferedReader(inputStreamReader);

            while ((tempLine = reader.readLine()) != null) {
                resultBuffer.append(tempLine).append("\n");
            }

        } finally {

            if (outputStreamWriter != null) {
                outputStreamWriter.close();
            }

            if (outputStream != null) {
                outputStream.close();
            }

            if (reader != null) {
                reader.close();
            }

            if (inputStreamReader != null) {
                inputStreamReader.close();
            }

            if (inputStream != null) {
                inputStream.close();
            }

        }

        return resultBuffer.toString();
    }


    public static boolean isLocalPortUsing(int port) {
        boolean flag = true;
        try {
            flag = usingPort("127.0.0.1", port);
        } catch (Exception e) {
        }
        return flag;
    }

    /***
     *  true:already in using  false:not using
     * @param host
     * @param port
     * @throws UnknownHostException
     */
    public static boolean usingPort(String host, int port) throws UnknownHostException {
        boolean flag = false;
        InetAddress theAddress = InetAddress.getByName(host);
        try {
            new Socket(theAddress, port);
            flag = true;
        } catch (IOException e) {
        }
        return flag;
    }


    public static int freePort() {
        Random random = new Random();
        int port;
        do {
            port = random.nextInt(65535);
        } while (isLocalPortUsing(port));

        return port;
    }

}