com.github.walterfan.util.http.URLHelper.java Source code

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Here is the source code for com.github.walterfan.util.http.URLHelper.java

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/**
 *
 * Copyright 2004 Protique 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.github.walterfan.util.http;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;

/**
 * Some URI based helper methods.
 * Walter revised from package org.codehaus.activemq.uti
 * @version 1.0
 */
public final class URLHelper {

    private URLHelper() {

    }

    /**
     * Parsers the query string of the URI into a map of key-value pairs
     */
    public static Map<String, String> parseQuery(URI uri) {
        return parseQuery(uri.getQuery());
    }

    /**
     * Parsers the query string of the URI into a map of key-value pairs
     */
    public static Map<String, String> parseQuery(String query) {
        Map<String, String> answer = new HashMap<String, String>();
        if (query != null) {
            StringTokenizer iter = new StringTokenizer(query, "&");
            while (iter.hasMoreTokens()) {
                String pair = iter.nextToken();
                addKeyValuePair(answer, pair);
            }
        }
        return answer;
    }

    protected static void addKeyValuePair(Map<String, String> answer, String pair) {
        int idx = pair.indexOf('=');
        String name = null;
        String value = null;
        if (idx >= 0) {
            name = pair.substring(0, idx);
            if (++idx < pair.length()) {
                value = pair.substring(idx);
            }
        } else {
            name = pair;
        }
        answer.put(name, value);
    }

    public static String getPathAndQuery(String strUrl) {
        try {
            URL url = new URL(strUrl);
            //System.out.println("url=" + url);
            String path = url.getPath();
            String query = url.getQuery();
            if (StringUtils.isNotBlank(query)) {
                path = path + "?" + query;
            }
            if (path.startsWith("/")) {
                return path.substring(1);
            }

        } catch (MalformedURLException e) {
            e.printStackTrace();

        }
        return "";
    }

    public static void URL2File(String strUrl) {
        URL2File(strUrl);
    }

    public static String URL2String(String strUrl) {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        try {
            URL2Stream(strUrl, output);
        } catch (IOException e) {
            e.printStackTrace();
            return "";
        }
        return output.toString();
    }

    public static void URL2Stream(String strUrl, OutputStream os) throws IOException {
        InputStream input = null;
        try {
            URL url = new URL(strUrl);
            input = url.openStream();
            IOUtils.copy(input, os);
        } finally {
            IOUtils.closeQuietly(input);
        }
    }

    public static void URL2File(String strUrl, String filename) {
        OutputStream output = null;
        try {
            if (null == filename) {
                URL url = new URL(strUrl);
                filename = FilenameUtils.getName(url.getFile());
            }
            System.out.println("write " + filename);
            File file = new File(filename);
            output = new FileOutputStream(file);
            URL2Stream(strUrl, output);

        } catch (MalformedURLException ex) {
            System.err.println(ex);
        } catch (FileNotFoundException ex) {
            System.err.println("Failed to open stream to URL: " + ex);
        } catch (IOException ex) {
            System.err.println("Error reading URL content: " + ex);
        } finally {
            IOUtils.closeQuietly(output);
        }
    }

    public static void main(String[] args) {
        String strUrl = "http://localhost";
        if (args.length < 1) {
            System.err.println("Usage: URLGet URL");
        } else {
            strUrl = args[0];
        }
        String str = URL2String(strUrl);
        System.out.println(str);
    }
}