Java XPath Get getLatestVersion(String tempDir, String url, String groupId, String artifactId, String version)

Description

get Latest Version

License

Apache License

Declaration

public static String getLatestVersion(String tempDir, String url, String groupId, String artifactId,
            String version) throws Exception 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2014 eBay Software Foundation.
 *
 * 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./* w w w. j  a va 2s . c  o m*/
 *******************************************************************************/

import java.io.File;

import java.io.FileOutputStream;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.Date;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class Main {
    public static String getLatestVersion(String tempDir, String url, String groupId, String artifactId,
            String version) throws Exception {
        return getLatestVersion(tempDir, url, null, groupId, artifactId, version);
    }

    public static String getLatestVersion(String tempDir, String url, String snapshotUrl, String groupId,
            String artifactId, String version) throws Exception {

        String latestVersion = null;

        String metaUrl = null;
        if (version == null) {
            metaUrl = url + "/" + groupId.replace(".", "/") + "/" + artifactId + "/maven-metadata.xml";
        } else {
            if (version.contains("SNAPSHOT") && snapshotUrl != null && !snapshotUrl.trim().isEmpty()) {
                metaUrl = snapshotUrl + "/" + groupId.replace(".", "/") + "/" + artifactId + "/" + version
                        + "/maven-metadata.xml";
            } else {
                metaUrl = url + "/" + groupId.replace(".", "/") + "/" + artifactId + "/" + version
                        + "/maven-metadata.xml";
            }
        }

        String tempPath = tempDir + "/" + groupId + "." + artifactId + "-" + new Date().getTime()
                + "-maven-metadata.xml";
        downloadFile(metaUrl, tempPath);

        // get the factory
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document dom = builder.parse(new File(tempPath));
        XPath xpath = XPathFactory.newInstance().newXPath();
        // XPath Query for showing all nodes value
        String xPathString = null;
        if (version == null) {
            xPathString = "//versioning/versions/version";
        } else {
            xPathString = "//versioning/snapshotVersions/snapshotVersion/value";
        }

        XPathExpression expr = xpath.compile(xPathString);

        NodeList list = (NodeList) expr.evaluate(dom, XPathConstants.NODESET);

        if (list != null) {
            String latest = ((Element) list.item(0)).getTextContent();
            for (int i = 1; i < list.getLength(); i++) {
                String temp = ((Element) list.item(i)).getTextContent();
                if (compareToVersion(temp, latest) > 0) {
                    latest = temp;
                }
            }

            latestVersion = latest;

        }

        return latestVersion;
    }

    /**
     * Download the url page content and save it to local file
     * 
     * @param urlString
     * @param filename
     * @throws Exception
     */
    public static void downloadFile(String urlString, String filename) throws Exception {
        URL url = new URL(urlString);
        URLConnection con = url.openConnection();
        con.setRequestProperty("User-Agent",
                "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:11.0) Gecko/20100101 Firefox/11.0");
        InputStream is = con.getInputStream();

        byte[] bs = new byte[1024];
        int len;
        OutputStream os = new FileOutputStream(filename);
        while ((len = is.read(bs)) != -1) {
            os.write(bs, 0, len);
        }
        os.close();
        is.close();
    }

    /**
     * 
     * @ver1 = ver2: return 0
     * @ver1 > ver2: return 1
     * @ver1 < ver2: return -1
     * 
     * @param ver1
     * @param ver2
     * @return
     */
    private static int compareToVersion(String ver1, String ver2) {
        if (ver1 == null && ver2 == null) {
            return 0;
        } else if (ver1 == null && ver2 != null) {
            return -1;
        } else if (ver1 != null && ver2 == null) {
            return 1;
        } else if (ver2.equalsIgnoreCase(ver1)) {
            return 0;
        } else {
            if (ver1.startsWith(ver2)) {
                return 1;
            } else if (ver2.startsWith(ver1)) {
                return -1;
            } else {
                String[] ver1Array = ver1.split("\\.");
                String[] ver2Array = ver2.split("\\.");

                for (int i = 0; ver1Array != null && ver2Array != null && i < ver1Array.length
                        && i < ver2Array.length; i++) {

                    if (ver1Array != null && ver2Array[i] != null && ver1Array[i].equals(ver2Array[i])) {
                        continue;
                    }

                    int int1 = 0;
                    int int2 = 0;
                    boolean isNumber = true;
                    try {
                        int1 = Integer.parseInt(ver1Array[i]);
                    } catch (NumberFormatException igore) {
                        isNumber = false;
                    }

                    try {
                        int2 = Integer.parseInt(ver2Array[i]);
                    } catch (NumberFormatException igore) {
                        isNumber = false;
                    }

                    if (isNumber) {
                        if (int1 != int2) {
                            return int1 - int2;
                        }
                    } else {
                        return ver1Array[i].compareTo(ver2Array[i]);
                    }
                }
            }
        }
        return 1;
    }
}

Related

1. getFastXPath(Node node)
2. getFirstByXPath(Object obj, String xpathExpression)
3. getFullXPath(Node n)
4. getHtmlXPath()
5. getInt(Object node, XPathExpression expression)
6. getListValue(Node node, XPathExpression expression)
7. getListValue(String targetDoc, List xpathExps, String encoding)
8. getMessage(XPathExpressionException e)
9. GetMobivateSessionId()