Android Path Relative Get getWindowsRelativePath(String basedir, String path)

Description

get Windows Relative Path

License

Open Source License

Declaration

public static String getWindowsRelativePath(String basedir, String path)

Method Source Code

/*//from ww w  .j  av  a2  s.  co m
 * Copyright (c) 2002-2012 Alibaba Group Holding Limited.
 * All rights reserved.
 *
 * 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.
 */

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import com.alibaba.antx.util.scanner.DefaultScannerHandler;
import com.alibaba.antx.util.scanner.DirectoryScanner;
import com.alibaba.antx.util.scanner.Scanner;
import com.alibaba.antx.util.scanner.ScannerException;

public class Main{
    private static final char COLON_CHAR = ':';
    private static final String UNC_PREFIX = "//";
    private static final String SLASH = "/";
    private static final char SLASH_CHAR = '/';
    private static final char BACKSLASH_CHAR = '\\';
    /** ??????????"." */
    public static final String CURRENT_DIR = ".";
    /** ?????????".." */
    public static final String UP_LEVEL_DIR = "..";
    
    public static String getWindowsRelativePath(String basedir, String path) {
        return getRelativePath(basedir, path, true);
    }
    
    public static String getRelativePath(String basedir, String path) {
        return getRelativePath(basedir, path, isWindows());
    }
    
    private static String getRelativePath(String basedir, String path,
            boolean isWindows) {
        // ????????basedir???????????
        basedir = normalizePath(basedir, isWindows);

        if (basedir == null) {
            return null;
        }

        String basePrefix = getSystemDependentPrefix(basedir, isWindows);

        if (basePrefix == null || basePrefix.length() == 0
                && !basedir.startsWith(SLASH)) {
            return null; // basedir????????
        }

        // ????????path
        path = getPathBasedOn(basedir, path, isWindows);

        if (path == null) {
            return null;
        }

        String prefix = getSystemDependentPrefix(path, isWindows);

        // ??path?basedir???????????????????????basedir??????
        // ????????path???????
        if (!basePrefix.equals(prefix)) {
            return path;
        }

        // ???path???"/"
        boolean endsWithSlash = path.endsWith(SLASH);

        // ?"/"??basedir?path
        String[] baseParts = StringUtil.split(
                basedir.substring(basePrefix.length()), SLASH);
        String[] parts = StringUtil.split(path.substring(prefix.length()),
                SLASH);
        StringBuffer buffer = new StringBuffer();
        int i = 0;

        if (isWindows) {
            while (i < baseParts.length && i < parts.length
                    && baseParts[i].equalsIgnoreCase(parts[i])) {
                i++;
            }
        } else {
            while (i < baseParts.length && i < parts.length
                    && baseParts[i].equals(parts[i])) {
                i++;
            }
        }

        if (i < baseParts.length && i < parts.length) {
            for (int j = i; j < baseParts.length; j++) {
                buffer.append(UP_LEVEL_DIR).append(SLASH_CHAR);
            }
        }

        for (; i < parts.length; i++) {
            buffer.append(parts[i]);

            if (i < parts.length - 1) {
                buffer.append(SLASH_CHAR);
            }
        }

        if (buffer.length() == 0) {
            buffer.append(CURRENT_DIR);
        }

        String relpath = buffer.toString();

        if (endsWithSlash && !relpath.endsWith(SLASH)) {
            relpath += SLASH;
        }

        return relpath;
    }
    private static boolean isWindows() {
        return System.getProperty("os.name").startsWith("Windows");
    }
    
    public static String normalizePath(String path) {
        return normalizePath(path, isWindows());
    }
    
    private static String normalizePath(String path, boolean isWindows) {
        if (path == null) {
            return null;
        }

        path = path.trim();

        // ?"\\"??????"/"?????????
        path = path.replace(BACKSLASH_CHAR, SLASH_CHAR);

        // ?????????????????windows?????????"C:"??"//hostname"
        String prefix = getSystemDependentPrefix(path, isWindows);

        if (prefix == null) {
            return null;
        }

        path = path.substring(prefix.length());

        // ????????prefix???"/"??????????????prefix.length > 0
        if (prefix.length() > 0 || path.startsWith(SLASH)) {
            prefix += SLASH_CHAR;
        }

        // ???path???"/"
        boolean endsWithSlash = path.endsWith(SLASH);

        // ??????"."?".."
        StringTokenizer tokenizer = new StringTokenizer(path, "/");
        StringBuffer buffer = new StringBuffer(prefix.length()
                + path.length());
        int level = 0;

        buffer.append(prefix);

        while (tokenizer.hasMoreTokens()) {
            String element = tokenizer.nextToken();

            // ??"."
            if (CURRENT_DIR.equals(element)) {
                continue;
            }

            // ??".."
            if (UP_LEVEL_DIR.equals(element)) {
                if (level == 0) {
                    // ??prefix?????????????????????????
                    // ??null??????????
                    if (prefix.length() > 0) {
                        return null;
                    }

                    buffer.append(UP_LEVEL_DIR).append(SLASH_CHAR);
                } else {
                    level--;

                    boolean found = false;

                    for (int i = buffer.length() - 2; i >= prefix.length(); i--) {
                        if (buffer.charAt(i) == SLASH_CHAR) {
                            buffer.setLength(i + 1);
                            found = true;
                            break;
                        }
                    }

                    if (!found) {
                        buffer.setLength(prefix.length());
                    }
                }

                continue;
            }

            // ???path
            buffer.append(element).append(SLASH_CHAR);
            level++;
        }

        // ????????????"./"
        if (buffer.length() == 0) {
            buffer.append(CURRENT_DIR).append(SLASH_CHAR);
        }

        // ????????"/"
        if (!endsWithSlash && buffer.length() > prefix.length()
                && buffer.charAt(buffer.length() - 1) == SLASH_CHAR) {
            buffer.setLength(buffer.length() - 1);
        }

        return buffer.toString();
    }
    
    private static String getSystemDependentPrefix(String path,
            boolean isWindows) {
        if (isWindows) {
            // ??UNC??
            if (path.startsWith(UNC_PREFIX)) {
                // ????UNC???"//"
                if (path.length() == UNC_PREFIX.length()) {
                    return null;
                }

                // ???????//hostname/subpath???//hostname
                int index = path.indexOf(SLASH, UNC_PREFIX.length());

                if (index != -1) {
                    return path.substring(0, index);
                } else {
                    return path;
                }
            }

            // ??Windows??????"c:/..."
            if (path.length() > 1 && path.charAt(1) == COLON_CHAR) {
                return path.substring(0, 2).toUpperCase();
            }
        }

        return "";
    }
    
    public static String getPathBasedOn(String basedir, String path) {
        return getPathBasedOn(basedir, path, isWindows());
    }
    
    private static String getPathBasedOn(String basedir, String path,
            boolean isWindows) {
        /*
         * ------------------------------------------- * ??????path??????????????????
         * * ???????????????normalize?????? *
         * -------------------------------------------
         */
        if (path == null) {
            return null;
        }

        path = path.trim();

        // ?"\\"??????"/"?????????
        path = path.replace(BACKSLASH_CHAR, SLASH_CHAR);

        // ?????????????????windows?????????"C:"??"//hostname"
        String prefix = getSystemDependentPrefix(path, isWindows);

        if (prefix == null) {
            return null;
        }

        // ??????????????
        if (prefix.length() > 0 || path.length() > prefix.length()
                && path.charAt(prefix.length()) == SLASH_CHAR) {
            return normalizePath(path, isWindows);
        }

        /*
         * ------------------------------------------- * ???????path?????????????
         * * ???basedir????? * -------------------------------------------
         */
        if (basedir == null) {
            return null;
        }

        StringBuffer buffer = new StringBuffer();

        buffer.append(basedir.trim());

        // ???????"/"????????UNC prefix??
        if (basedir.length() > 0 && path.length() > 0
                && basedir.charAt(basedir.length() - 1) != SLASH_CHAR) {
            buffer.append(SLASH_CHAR);
        }

        buffer.append(path);

        return normalizePath(buffer.toString(), isWindows);
    }
}

Android Path Relative Get getWindowsRelativePath(String basedir, String path)

Description

License

Declaration

Method Source Code

Related