Java HttpURLConnection.getLastModified方法代码示例

import java.net.HttpURLConnection; //导入方法依赖的package包/类
public static Long findTidsstempelForSenesteAPK() throws Exception {
  if (APK_URL==null || APK_URL.length()==0) return null;
  /*
  final PackageManager pm = getPackageManager();
  String apkName = "example.apk";
  String fullPath = Environment.getExternalStorageDirectory() + "/" + apkName;
  PackageInfo info = pm.getPackageArchiveInfo(fullPath, 0);
  Toast.makeText(this, "VersionCode : " + info.versionCode + ", VersionName : " + info.versionName , Toast.LENGTH_LONG).show();
  */
  URL url = new URL(APK_URL);
  HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
  if (urlConnection.getResponseCode()!= HttpURLConnection.HTTP_OK) return null;
  if (!url.getHost().equals(urlConnection.getURL().getHost())) return null; // ingen omdirigeringer
  long lm = urlConnection.getLastModified();
  return lm;
}
 

import java.net.HttpURLConnection; //导入方法依赖的package包/类
private URLConnection openConnection(URL aSource) throws IOException {

            // set up the URL connection
            URLConnection connection = aSource.openConnection();
            // modify the headers
            // NB: things like user authentication could go in here too.
            if (hasTimestamp) {
                connection.setIfModifiedSince(timestamp);
            }

            // in case the plugin manager is its own project, this can become an authenticator
            boolean isSecureProcotol = "https".equalsIgnoreCase(aSource.getProtocol());
            boolean isAuthInfoSet = !Strings.isNullOrEmpty(aSource.getUserInfo());
            if (isAuthInfoSet) {
                if (!isSecureProcotol) {
                    throw new IOException("Basic auth is only supported for HTTPS!");
                }
                String basicAuth = Base64.encodeBytes(aSource.getUserInfo().getBytes(StandardCharsets.UTF_8));
                connection.setRequestProperty("Authorization", "Basic " + basicAuth);
            }

            if (connection instanceof HttpURLConnection) {
                ((HttpURLConnection) connection).setInstanceFollowRedirects(false);
                connection.setUseCaches(true);
                connection.setConnectTimeout(5000);
            }
            connection.setRequestProperty("ES-Version", Version.CURRENT.toString());
            connection.setRequestProperty("ES-Build-Hash", Build.CURRENT.hashShort());
            connection.setRequestProperty("User-Agent", "elasticsearch-plugin-manager");

            // connect to the remote site (may take some time)
            connection.connect();

            // First check on a 301 / 302 (moved) response (HTTP only)
            if (connection instanceof HttpURLConnection) {
                HttpURLConnection httpConnection = (HttpURLConnection) connection;
                int responseCode = httpConnection.getResponseCode();
                if (responseCode == HttpURLConnection.HTTP_MOVED_PERM ||
                        responseCode == HttpURLConnection.HTTP_MOVED_TEMP ||
                        responseCode == HttpURLConnection.HTTP_SEE_OTHER) {
                    String newLocation = httpConnection.getHeaderField("Location");
                    URL newURL = new URL(newLocation);
                    if (!redirectionAllowed(aSource, newURL)) {
                        return null;
                    }
                    return openConnection(newURL);
                }
                // next test for a 304 result (HTTP only)
                long lastModified = httpConnection.getLastModified();
                if (responseCode == HttpURLConnection.HTTP_NOT_MODIFIED
                        || (lastModified != 0 && hasTimestamp && timestamp >= lastModified)) {
                    // not modified so no file download. just return
                    // instead and trace out something so the user
                    // doesn't think that the download happened when it
                    // didn't
                    return null;
                }
                // test for 401 result (HTTP only)
                if (responseCode == HttpURLConnection.HTTP_UNAUTHORIZED) {
                    String message = "HTTP Authorization failure";
                    throw new IOException(message);
                }
            }

            //REVISIT: at this point even non HTTP connections may
            //support the if-modified-since behaviour -we just check
            //the date of the content and skip the write if it is not
            //newer. Some protocols (FTP) don't include dates, of
            //course.
            return connection;
        }
 

import java.net.HttpURLConnection; //导入方法依赖的package包/类
/**
 * Check if there is a new version of the script engine
 * 
 * @throws IOException
 *             if any error occur
 */
private void download() throws IOException {
    boolean is32 = "32".equals( System.getProperty( "sun.arch.data.model" ) );
    String fileName;
    final String os = System.getProperty( "os.name", "" ).toLowerCase();
    if( os.contains( "windows" ) ) {
        fileName = is32 ? "win32" : "win64";
    } else if( os.contains( "mac" ) ) {
        fileName = is32 ? "mac" : "mac64";
    } else if( os.contains( "linux" ) ) {
        fileName = is32 ? "linux-i686" : "linux-x86_64";
    } else {
        throw new IllegalStateException( "Unknown OS: " + os );
    }
    File target = new File( System.getProperty( "java.io.tmpdir" ) + "/SpiderMonkey" );
    URL url = new URL( "https://archive.mozilla.org/pub/firefox/nightly/latest-mozilla-central/jsshell-" + fileName
                    + ".zip" );
    System.out.println( "\tDownload: " + url );
    HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    if( target.exists() ) {
        System.out.println( "\tUP-TP-DATE" );
        conn.setIfModifiedSince( target.lastModified() );
    }
    InputStream input = conn.getInputStream();
    command = target.getAbsolutePath() + "/js";
    if( conn.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED ) {
        return;
    }
    ZipInputStream zip = new ZipInputStream( input );
    long lastModfied = conn.getLastModified();
    do {
        ZipEntry entry = zip.getNextEntry();
        if( entry == null ) {
            break;
        }
        if( entry.isDirectory() ) {
            continue;
        }
        File file = new File( target, entry.getName() );
        file.getParentFile().mkdirs();

        Files.copy( zip, file.toPath(), StandardCopyOption.REPLACE_EXISTING );
        file.setLastModified( entry.getTime() );
        if( "js".equals( file.getName() ) ) {
            file.setExecutable( true );
        }
    } while( true );
    target.setLastModified( lastModfied );
}