废话不多说，直接上代码。
验证类Validator
主要是空验证、数字、格式验证
调用的例子：
protected void validateEmailFrom(ActionRequest actionRequest){ String emailFromName = getParameter(actionRequest, "emailFromName"); String emailFromAddress = getParameter( actionRequest, "emailFromAddress"); if (Validator.isNull(emailFromName)) { SessionErrors.add(actionRequest, "emailFromName"); } else if (!Validator.isEmailAddress(emailFromAddress) && !Validator.isVariableTerm(emailFromAddress)) { SessionErrors.add(actionRequest, "emailFromAddress"); } }
数组工具类，ArrayUtil
主要的操作是：
源代码实现分析1、去除重复值，如
public static String[] distinct(String[] array) { return distinct(array, null); } public static String[] distinct( String[] array, Comparator<String> comparator) { if ((array == null) || (array.length == 0)) { return array; } Set<String> set = null; if (comparator == null) { set = new TreeSet<String>(); } else { set = new TreeSet<String>(comparator); } for (int i = 0; i < array.length; i++) { String s = array[i]; if (!set.contains(s)) { set.add(s); } } return set.toArray(new String[set.size()]); }
源代码实现分析2、尾部增加项，比如：
public static Float[] append(Float[] array, Float obj) { Float[] newArray = new Float[array.length + 1]; System.arraycopy(array, 0, newArray, 0, array.length); newArray[newArray.length - 1] = obj; return newArray; }
3、JSONArray、Object和Array转换，如：
static String[] toStringArray(JSONArray array) static String[] toStringArray(Object[] array)
字符串工具StringUtil
一个例子，用于字符替换，同时也使用了StringPool
protected Map<String, String> getJSONValues(
JSONArray data, String namespace, String id) {
Map<String, String> values = new HashMap<String, String>(data.length());
for (int i = 0; i < data.length(); i++) {
JSONObject jsonObject = data.getJSONObject(i);
String name = jsonObject.getString("name");
name = StringUtil.replace(
name, new String[] {namespace, id},
new String[] {StringPool.BLANK, StringPool.BLANK});
values.put(name, jsonObject.getString("value"));
}
return values;
}
StringUtil源代码，有兴趣可以研究
package com.liferay.portal.kernel.util; import com.liferay.portal.kernel.log.Log; import com.liferay.portal.kernel.log.LogFactoryUtil; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.StringReader; import java.net.URL; import java.util.ArrayList; import java.util.Collection; import java.util.Enumeration; import java.util.List; import java.util.Map; import java.util.StringTokenizer; public class StringUtil { public static String add(String s, String add) { return add(s, add, StringPool.COMMA); } public static String add(String s, String add, String delimiter) { return add(s, add, delimiter, false); } public static String add( String s, String add, String delimiter, boolean allowDuplicates) { if ((add == null) || (delimiter == null)) { return null; } if (s == null) { s = StringPool.BLANK; } if (allowDuplicates || !contains(s, add, delimiter)) { StringBuilder sb = new StringBuilder(); sb.append(s); if (Validator.isNull(s) || s.endsWith(delimiter)) { sb.append(add); sb.append(delimiter); } else { sb.append(delimiter); sb.append(add); sb.append(delimiter); } s = sb.toString(); } return s; } public static String bytesToHexString(byte[] bytes) { StringBuilder sb = new StringBuilder(bytes.length * 2); for (int i = 0; i < bytes.length; i++) { String hex = Integer.toHexString( 0x0100 + (bytes[i] & 0x00FF)).substring(1); if (hex.length() < 2) { sb.append("0"); } sb.append(hex); } return sb.toString(); } public static boolean contains(String s, String text) { return contains(s, text, StringPool.COMMA); } public static boolean contains(String s, String text, String delimiter) { if ((s == null) || (text == null) || (delimiter == null)) { return false; } StringBuilder sb = null; if (!s.endsWith(delimiter)) { sb = new StringBuilder(); sb.append(s); sb.append(delimiter); s = sb.toString(); } sb = new StringBuilder(); sb.append(delimiter); sb.append(text); sb.append(delimiter); String dtd = sb.toString(); int pos = s.indexOf(dtd); if (pos == -1) { sb = new StringBuilder(); sb.append(text); sb.append(delimiter); String td = sb.toString(); if (s.startsWith(td)) { return true; } return false; } return true; } public static int count(String s, String text) { if ((s == null) || (text == null)) { return 0; } int count = 0; int pos = s.indexOf(text); while (pos != -1) { pos = s.indexOf(text, pos + text.length()); count++; } return count; } public static boolean endsWith(String s, char end) { return endsWith(s, (new Character(end)).toString()); } public static boolean endsWith(String s, String end) { if ((s == null) || (end == null)) { return false; } if (end.length() > s.length()) { return false; } String temp = s.substring(s.length() - end.length(), s.length()); if (temp.equalsIgnoreCase(end)) { return true; } else { return false; } } public static String extractChars(String s) { if (s == null) { return StringPool.BLANK; } StringBuilder sb = new StringBuilder(); char[] c = s.toCharArray(); for (int i = 0; i < c.length; i++) { if (Validator.isChar(c[i])) { sb.append(c[i]); } } return sb.toString(); } public static String extractDigits(String s) { if (s == null) { return StringPool.BLANK; } StringBuilder sb = new StringBuilder(); char[] c = s.toCharArray(); for (int i = 0; i < c.length; i++) { if (Validator.isDigit(c[i])) { sb.append(c[i]); } } return sb.toString(); } public static String extractFirst(String s, String delimiter) { if (s == null) { return null; } else { String[] array = split(s, delimiter); if (array.length > 0) { return array[0]; } else { return null; } } } public static String extractLast(String s, String delimiter) { if (s == null) { return null; } else { String[] array = split(s, delimiter); if (array.length > 0) { return array[array.length - 1]; } else { return null; } } } public static String highlight(String s, String keywords) { return highlight(s, keywords, "<span class="highlight">", "</span>"); } public static String highlight( String s, String keywords, String highlight1, String highlight2) { if (s == null) { return null; } // The problem with using a regexp is that it searches the text in a // case insenstive manner but doens't replace the text in a case // insenstive manner. So the search results actually get messed up. The // best way is to actually parse the results. //return s.replaceAll( // "(?i)" + keywords, highlight1 + keywords + highlight2); StringBuilder sb = new StringBuilder(StringPool.SPACE); StringTokenizer st = new StringTokenizer(s); while (st.hasMoreTokens()) { String token = st.nextToken(); if (token.equalsIgnoreCase(keywords)) { sb.append(highlight1); sb.append(token); sb.append(highlight2); } else { sb.append(token); } if (st.hasMoreTokens()) { sb.append(StringPool.SPACE); } } return sb.toString(); } public static String lowerCase(String s) { if (s == null) { return null; } else { return s.toLowerCase(); } } public static String merge(boolean[] array) { return merge(array, StringPool.COMMA); } public static String merge(boolean[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(double[] array) { return merge(array, StringPool.COMMA); } public static String merge(double[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(float[] array) { return merge(array, StringPool.COMMA); } public static String merge(float[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(int[] array) { return merge(array, StringPool.COMMA); } public static String merge(int[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(long[] array) { return merge(array, StringPool.COMMA); } public static String merge(long[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(short[] array) { return merge(array, StringPool.COMMA); } public static String merge(short[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String merge(Collection<?> col) { return merge(col, StringPool.COMMA); } public static String merge(Collection<?> col, String delimiter) { return merge(col.toArray(new Object[col.size()]), delimiter); } public static String merge(Object[] array) { return merge(array, StringPool.COMMA); } public static String merge(Object[] array, String delimiter) { if (array == null) { return null; } StringBuilder sb = new StringBuilder(); for (int i = 0; i < array.length; i++) { sb.append(String.valueOf(array[i]).trim()); if ((i + 1) != array.length) { sb.append(delimiter); } } return sb.toString(); } public static String randomize(String s) { return Randomizer.getInstance().randomize(s); } public static String read(ClassLoader classLoader, String name) throws IOException { return read(classLoader, name, false); } public static String read(ClassLoader classLoader, String name, boolean all) throws IOException { if (all) { StringBuilder sb = new StringBuilder(); Enumeration<URL> enu = classLoader.getResources(name); while (enu.hasMoreElements()) { URL url = enu.nextElement(); InputStream is = url.openStream(); String s = read(is); if (s != null) { sb.append(s); sb.append(StringPool.NEW_LINE); } is.close(); } return sb.toString().trim(); } else { InputStream is = classLoader.getResourceAsStream(name); String s = read(is); is.close(); return s; } } public static String read(InputStream is) throws IOException { StringBuilder sb = new StringBuilder(); BufferedReader br = new BufferedReader(new InputStreamReader(is)); String line = null; while ((line = br.readLine()) != null) { sb.append(line).append(' '); } br.close(); return sb.toString().trim(); } public static String remove(String s, String remove) { return remove(s, remove, StringPool.COMMA); } public static String remove(String s, String remove, String delimiter) { if ((s == null) || (remove == null) || (delimiter == null)) { return null; } if (Validator.isNotNull(s) && !s.endsWith(delimiter)) { s += delimiter; } StringBuilder sb = new StringBuilder(); sb.append(delimiter); sb.append(remove); sb.append(delimiter); String drd = sb.toString(); sb = new StringBuilder(); sb.append(remove); sb.append(delimiter); String rd = sb.toString(); while (contains(s, remove, delimiter)) { int pos = s.indexOf(drd); if (pos == -1) { if (s.startsWith(rd)) { int x = remove.length() + delimiter.length(); int y = s.length(); s = s.substring(x, y); } } else { int x = pos + remove.length() + delimiter.length(); int y = s.length(); sb = new StringBuilder(); sb.append(s.substring(0, pos)); sb.append(s.substring(x, y)); s = sb.toString(); } } return s; } public static String replace(String s, char oldSub, char newSub) { if (s == null) { return null; } return s.replace(oldSub, newSub); } public static String replace(String s, char oldSub, String newSub) { if ((s == null) || (newSub == null)) { return null; } // The number 5 is arbitrary and is used as extra padding to reduce // buffer expansion StringBuilder sb = new StringBuilder(s.length() + 5 * newSub.length()); char[] charArray = s.toCharArray(); for (char c : charArray) { if (c == oldSub) { sb.append(newSub); } else { sb.append(c); } } return sb.toString(); } public static String replace(String s, String oldSub, String newSub) { if ((s == null) || (oldSub == null) || (newSub == null)) { return null; } int y = s.indexOf(oldSub); if (y >= 0) { // The number 5 is arbitrary and is used as extra padding to reduce // buffer expansion StringBuilder sb = new StringBuilder( s.length() + 5 * newSub.length()); int length = oldSub.length(); int x = 0; while (x <= y) { sb.append(s.substring(x, y)); sb.append(newSub); x = y + length; y = s.indexOf(oldSub, x); } sb.append(s.substring(x)); return sb.toString(); } else { return s; } } public static String replace(String s, String[] oldSubs, String[] newSubs) { if ((s == null) || (oldSubs == null) || (newSubs == null)) { return null; } if (oldSubs.length != newSubs.length) { return s; } for (int i = 0; i < oldSubs.length; i++) { s = replace(s, oldSubs[i], newSubs[i]); } return s; } public static String replace( String s, String[] oldSubs, String[] newSubs, boolean exactMatch) { if ((s == null) || (oldSubs == null) || (newSubs == null)) { return null; } if (oldSubs.length != newSubs.length) { return s; } if (!exactMatch) { replace(s, oldSubs, newSubs); } else { for (int i = 0; i < oldSubs.length; i++) { s = s.replaceAll("\b" + oldSubs[i] + "\b" , newSubs[i]); } } return s; } /** * Returns a string with replaced values. This method will replace all text * in the given string, between the beginning and ending delimiter, with new * values found in the given map. For example, if the string contained the * text <code>[$HELLO$]</code>, and the beginning delimiter was * <code>[$]</code>, and the ending delimiter was <code>$]</code>, and the * values map had a key of <code>HELLO</code> that mapped to * <code>WORLD</code>, then the replaced string will contain the text * <code>[$WORLD$]</code>. * * @param s the original string * @param begin the beginning delimiter * @param end the ending delimiter * @param values a map of old and new values * @return a string with replaced values */ public static String replaceValues( String s, String begin, String end, Map<String, String> values) { if ((s == null) || (begin == null) || (end == null) || (values == null) || (values.size() == 0)) { return s; } StringBuilder sb = new StringBuilder(s.length()); int pos = 0; while (true) { int x = s.indexOf(begin, pos); int y = s.indexOf(end, x + begin.length()); if ((x == -1) || (y == -1)) { sb.append(s.substring(pos, s.length())); break; } else { sb.append(s.substring(pos, x + begin.length())); String oldValue = s.substring(x + begin.length(), y); String newValue = values.get(oldValue); if (newValue == null) { newValue = oldValue; } sb.append(newValue); pos = y; } } return sb.toString(); } public static String reverse(String s) { if (s == null) { return null; } char[] c = s.toCharArray(); char[] reverse = new char[c.length]; for (int i = 0; i < c.length; i++) { reverse[i] = c[c.length - i - 1]; } return new String(reverse); } public static String safePath(String path) { return replace(path, StringPool.DOUBLE_SLASH, StringPool.SLASH); } public static String shorten(String s) { return shorten(s, 20); } public static String shorten(String s, int length) { return shorten(s, length, "..."); } public static String shorten(String s, String suffix) { return shorten(s, 20, suffix); } public static String shorten(String s, int length, String suffix) { if ((s == null) || (suffix == null)) { return null; } if (s.length() > length) { for (int j = length; j >= 0; j--) { if (Character.isWhitespace(s.charAt(j))) { length = j; break; } } StringBuilder sb = new StringBuilder(); sb.append(s.substring(0, length)); sb.append(suffix); s = sb.toString(); } return s; } public static String[] split(String s) { return split(s, StringPool.COMMA); } public static String[] split(String s, String delimiter) { if (s == null || delimiter == null) { return new String[0]; } s = s.trim(); if (!s.endsWith(delimiter)) { StringBuilder sb = new StringBuilder(); sb.append(s); sb.append(delimiter); s = sb.toString(); } if (s.equals(delimiter)) { return new String[0]; } List<String> nodeValues = new ArrayList<String>(); if (delimiter.equals(" ") || delimiter.equals(" ")) { try { BufferedReader br = new BufferedReader(new StringReader(s)); String line = null; while ((line = br.readLine()) != null) { nodeValues.add(line); } br.close(); } catch (IOException ioe) { _log.error(ioe.getMessage()); } } else { int offset = 0; int pos = s.indexOf(delimiter, offset); while (pos != -1) { nodeValues.add(new String(s.substring(offset, pos))); offset = pos + delimiter.length(); pos = s.indexOf(delimiter, offset); } } return nodeValues.toArray(new String[nodeValues.size()]); } public static boolean[] split(String s, boolean x) { return split(s, StringPool.COMMA, x); } public static boolean[] split(String s, String delimiter, boolean x) { String[] array = split(s, delimiter); boolean[] newArray = new boolean[array.length]; for (int i = 0; i < array.length; i++) { boolean value = x; try { value = Boolean.valueOf(array[i]).booleanValue(); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static double[] split(String s, double x) { return split(s, StringPool.COMMA, x); } public static double[] split(String s, String delimiter, double x) { String[] array = split(s, delimiter); double[] newArray = new double[array.length]; for (int i = 0; i < array.length; i++) { double value = x; try { value = Double.parseDouble(array[i]); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static float[] split(String s, float x) { return split(s, StringPool.COMMA, x); } public static float[] split(String s, String delimiter, float x) { String[] array = split(s, delimiter); float[] newArray = new float[array.length]; for (int i = 0; i < array.length; i++) { float value = x; try { value = Float.parseFloat(array[i]); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static int[] split(String s, int x) { return split(s, StringPool.COMMA, x); } public static int[] split(String s, String delimiter, int x) { String[] array = split(s, delimiter); int[] newArray = new int[array.length]; for (int i = 0; i < array.length; i++) { int value = x; try { value = Integer.parseInt(array[i]); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static long[] split(String s, long x) { return split(s, StringPool.COMMA, x); } public static long[] split(String s, String delimiter, long x) { String[] array = split(s, delimiter); long[] newArray = new long[array.length]; for (int i = 0; i < array.length; i++) { long value = x; try { value = Long.parseLong(array[i]); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static short[] split(String s, short x) { return split(s, StringPool.COMMA, x); } public static short[] split(String s, String delimiter, short x) { String[] array = split(s, delimiter); short[] newArray = new short[array.length]; for (int i = 0; i < array.length; i++) { short value = x; try { value = Short.parseShort(array[i]); } catch (Exception e) { } newArray[i] = value; } return newArray; } public static boolean startsWith(String s, char begin) { return startsWith(s, (new Character(begin)).toString()); } public static boolean startsWith(String s, String start) { if ((s == null) || (start == null)) { return false; } if (start.length() > s.length()) { return false; } String temp = s.substring(0, start.length()); if (temp.equalsIgnoreCase(start)) { return true; } else { return false; } } /** * Return the number of starting letters that s1 and s2 have in common * before they deviate. * * @param s1 the first string * @param s2 the second string * * @return the number of starting letters that s1 and s2 have in common * before they deviate */ public static int startsWithWeight(String s1, String s2) { if ((s1 == null) || (s2 == null)) { return 0; } char[] charArray1 = s1.toCharArray(); char[] charArray2 = s2.toCharArray(); int i = 0; for (; (i < charArray1.length) && (i < charArray2.length); i++) { if (charArray1[i] != charArray2[i]) { break; } } return i; } public static String stripBetween(String s, String begin, String end) { if ((s == null) || (begin == null) || (end == null)) { return s; } StringBuilder sb = new StringBuilder(s.length()); int pos = 0; while (true) { int x = s.indexOf(begin, pos); int y = s.indexOf(end, x + begin.length()); if ((x == -1) || (y == -1)) { sb.append(s.substring(pos, s.length())); break; } else { sb.append(s.substring(pos, x)); pos = y + end.length(); } } return sb.toString(); } public static String trim(String s) { return trim(s, null); } public static String trim(String s, char c) { return trim(s, new char[] {c}); } public static String trim(String s, char[] exceptions) { if (s == null) { return null; } char[] charArray = s.toCharArray(); int len = charArray.length; int x = 0; int y = charArray.length; for (int i = 0; i < len; i++) { char c = charArray[i]; if (_isTrimable(c, exceptions)) { x = i + 1; } else { break; } } for (int i = len - 1; i >= 0; i--) { char c = charArray[i]; if (_isTrimable(c, exceptions)) { y = i; } else { break; } } if ((x != 0) || (y != len)) { return s.substring(x, y); } else { return s; } } public static String trimLeading(String s) { return trimLeading(s, null); } public static String trimLeading(String s, char c) { return trimLeading(s, new char[] {c}); } public static String trimLeading(String s, char[] exceptions) { if (s == null) { return null; } char[] charArray = s.toCharArray(); int len = charArray.length; int x = 0; int y = charArray.length; for (int i = 0; i < len; i++) { char c = charArray[i]; if (_isTrimable(c, exceptions)) { x = i + 1; } else { break; } } if ((x != 0) || (y != len)) { return s.substring(x, y); } else { return s; } } public static String trimTrailing(String s) { return trimTrailing(s, null); } public static String trimTrailing(String s, char c) { return trimTrailing(s, new char[] {c}); } public static String trimTrailing(String s, char[] exceptions) { if (s == null) { return null; } char[] charArray = s.toCharArray(); int len = charArray.length; int x = 0; int y = charArray.length; for (int i = len - 1; i >= 0; i--) { char c = charArray[i]; if (_isTrimable(c, exceptions)) { y = i; } else { break; } } if ((x != 0) || (y != len)) { return s.substring(x, y); } else { return s; } } public static String upperCase(String s) { if (s == null) { return null; } else { return s.toUpperCase(); } } public static String upperCaseFirstLetter(String s) { char[] chars = s.toCharArray(); if ((chars[0] >= 97) && (chars[0] <= 122)) { chars[0] = (char)(chars[0] - 32); } return new String(chars); } public static String wrap(String text) { return wrap(text, 80, StringPool.NEW_LINE); } public static String wrap(String text, int width, String lineSeparator) { if (text == null) { return null; } StringBuilder sb = new StringBuilder(); try { BufferedReader br = new BufferedReader(new StringReader(text)); String s = StringPool.BLANK; while ((s = br.readLine()) != null) { if (s.length() == 0) { sb.append(lineSeparator); } else { String[] tokens = s.split(StringPool.SPACE); boolean firstWord = true; int curLineLength = 0; for (int i = 0; i < tokens.length; i++) { if (!firstWord) { sb.append(StringPool.SPACE); curLineLength++; } if (firstWord) { sb.append(lineSeparator); } sb.append(tokens[i]); curLineLength += tokens[i].length(); if (curLineLength >= width) { firstWord = true; curLineLength = 0; } else { firstWord = false; } } } } } catch (IOException ioe) { _log.error(ioe.getMessage()); } return sb.toString(); } private static boolean _isTrimable(char c, char[] exceptions) { if ((exceptions != null) && (exceptions.length > 0)) { for (int i = 0; i < exceptions.length; i++) { if (c == exceptions[i]) { return false; } } } return Character.isWhitespace(c); } private static Log _log = LogFactoryUtil.getLog(StringUtil.class); }
其他工具类
- 集合的泛型帮助类：MapUtil、ListUtil
- Base64的转换：Base64
- http参数帮助，编解码工具：HttpUtil
- 文件操作：FileUtil
- 类型工具：ClassUtil：
- 常用字符串静态类：StringPool
其中StringPool定义了一些final值，可以利用起来：
package com.liferay.portal.kernel.util; public class StringPool { public static final String AMPERSAND = "&"; public static final String AMPERSAND_ENCODED = "&"; public static final String APOSTROPHE = "'"; public static final String AT = "@"; public static final String BACK_SLASH = "\"; public static final String BETWEEN = "BETWEEN"; public static final String BLANK = ""; public static final String CDATA_OPEN = "<![CDATA["; public static final String CDATA_CLOSE = "]]>"; public static final String CLOSE_BRACKET = "]"; public static final String CLOSE_CURLY_BRACE = "}"; public static final String CLOSE_PARENTHESIS = ")"; public static final String COLON = ":"; public static final String COMMA = ","; public static final String COMMA_AND_SPACE = ", "; public static final String DASH = "-"; public static final String DOUBLE_APOSTROPHE = "''"; public static final String DOUBLE_CLOSE_BRACKET = "]]"; public static final String DOUBLE_OPEN_BRACKET = "[["; public static final String DOUBLE_SLASH = "//"; public static final String EQUAL = "="; public static final String GREATER_THAN = ">"; public static final String GREATER_THAN_OR_EQUAL = ">="; public static final String FALSE = "false"; public static final String FORWARD_SLASH = "/"; public static final String FOUR_SPACES = " "; public static final String IS_NOT_NULL = "IS NOT NULL"; public static final String IS_NULL = "IS NULL"; public static final String LESS_THAN = "<"; public static final String LESS_THAN_OR_EQUAL = "<="; public static final String LIKE = "LIKE"; public static final String MINUS = "-"; public static final String NBSP = " "; public static final String NEW_LINE = " "; public static final String NOT_EQUAL = "!="; public static final String NOT_LIKE = "NOT LIKE"; public static final String NULL = "null"; public static final String OPEN_BRACKET = "["; public static final String OPEN_CURLY_BRACE = "{"; public static final String OPEN_PARENTHESIS = "("; public static final String PERCENT = "%"; public static final String PERIOD = "."; public static final String PIPE = "|"; public static final String PLUS = "+"; public static final String POUND = "#"; public static final String QUESTION = "?"; public static final String QUOTE = """; public static final String RETURN = " "; public static final String RETURN_NEW_LINE = " "; public static final String SEMICOLON = ";"; public static final String SLASH = FORWARD_SLASH; public static final String SPACE = " "; public static final String STAR = "*"; public static final String TILDE = "~"; public static final String TRUE = "true"; public static final String UNDERLINE = "_"; public static final String UTF8 = "UTF-8"; }
简单、优雅、有序才是真的美。