关于PROPERTIES类的问题想请教？

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;public class PASProperties
        extends java.util.Properties {
    private static final String keyValueSeparators = "=: \t\r\n\f";    private static final String strictKeyValueSeparators = "=:";   // private static final String specialSaveChars = "=: \t\r\n\f#!";    private static final String whiteSpaceChars = " \t\r\n\f";
    /**
     * Load properties into the system
     * @param inStream    inputStream containing properties
     * @throws IOException    if the inputSteam is not valid
     */
    public synchronized void load(InputStream inStream) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(inStream));
        while (true) {
            // Get next line
            String line = in.readLine();
            if (line == null) {
                return;
            }            if (line.length() > 0) {
                // Continue lines that end in slashes if they are not comments
                char firstChar = line.charAt(0);
                if ((firstChar != '#') && (firstChar != '!')) {
                    while (continueLine(line)) {
                        String nextLine = in.readLine();
                        if (nextLine == null) {
                            nextLine = "";
                        }
                        String loppedLine = line.substring(0, line.length() - 1);
                        // Advance beyond whitespace on new line
                        int startIndex = 0;
                        for (startIndex = 0; startIndex < nextLine.length(); startIndex++) {
                            if (whiteSpaceChars.indexOf(nextLine.charAt(startIndex)) == -1) {
                                break;
                            }
                        }
                        nextLine = nextLine.substring(startIndex, nextLine.length());
                        line = new String(loppedLine + nextLine);
                    }                    // Find start of key
                    int len = line.length();
                    int keyStart;
                    for (keyStart = 0; keyStart < len; keyStart++) {
                        if (whiteSpaceChars.indexOf(line.charAt(keyStart)) == -1) {
                            break;
                        }
                    }                    // Blank lines are ignored
                    if (keyStart == len) {
                        continue;
                    }                    // Find separation between key and value
                    int separatorIndex;
                    for (separatorIndex = keyStart; separatorIndex < len; separatorIndex++) {
                        char currentChar = line.charAt(separatorIndex);
                        if (currentChar == '\\') {
                            separatorIndex++;
                        } else if (keyValueSeparators.indexOf(currentChar) != -1) {
                            break;
                        }
                    }                    // Skip over whitespace after key if any
                    int valueIndex;
                    for (valueIndex = separatorIndex; valueIndex < len; valueIndex++) {
                        if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1) {
                            break;
                        }
                    }                    // Skip over one non whitespace key value separators if any
                    if (valueIndex < len) {
                        if (strictKeyValueSeparators.indexOf(line.charAt(valueIndex)) != -1) {
                            valueIndex++;                            // Skip over white space after other separators if any
                        }
                    }
                    while (valueIndex < len) {
                        if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1) {
                            break;
                        }
                        valueIndex++;
                    }
                    String key = line.substring(keyStart, separatorIndex);
                    String value = (separatorIndex < len) ?
                            line.substring(valueIndex, len) : "";                    // Convert then store key and value
                    key = loadConvert(key);
                    value = loadConvert(value);
                    put(key, value);
                }
            }
        }
    }    /*
     * Returns true if the given line is a line that must
     * be appended to the next line
     */
    private boolean continueLine(String line) {
        int slashCount = 0;
        int index = line.length() - 1;
        while ((index >= 0) && (line.charAt(index--) == '\\'))
            slashCount++;
        return (slashCount % 2 == 1);
    }    /*
     * Converts encoded \\uxxxx to unicode chars
     * and changes special saved chars to their original forms
     */
    private String loadConvert(String theString) {
        char aChar;
        int len = theString.length();
        StringBuffer outBuffer = new StringBuffer(len);        for (int x = 0; x < len;) {
            aChar = theString.charAt(x++);
            if (aChar == '\\') {
                aChar = theString.charAt(x++);
                if (aChar == 'u') {
                    // Read the xxxx
                    int value = 0;
                    for (int i = 0; i < 4; i++) {
                        aChar = theString.charAt(x++);
                        switch (aChar) {
                            case '0':
                            case '1':
                            case '2':
                            case '3':
                            case '4':
                            case '5':
                            case '6':
                            case '7':
                            case '8':
                            case '9':
                                value = (value << 4) + aChar - '0';
                                break;
                            case 'a':
                            case 'b':
                            case 'c':
                            case 'd':
                            case 'e':
                            case 'f':
                                value = (value << 4) + 10 + aChar - 'a';
                                break;
                            case 'A':
                            case 'B':
                            case 'C':
                            case 'D':
                            case 'E':
                            case 'F':
                                value = (value << 4) + 10 + aChar - 'A';
                                break;
                            default:
                                throw new IllegalArgumentException("Malformed \\uxxxx encoding.");
                        }
                    }
                    outBuffer.append((char) value);
                } else {
                    if (aChar == 't')
                        aChar = '\t';
                    else if (aChar == 'r')
                        aChar = '\r';
                    else if (aChar == 'n')
                        aChar = '\n';
                    else if (aChar == 'f') aChar = '\f';
                    outBuffer.append(aChar);
                }
            } else
                outBuffer.append(aChar);
        }
        return outBuffer.toString();
    }}