liquibase.util.StringUtils Maven / Gradle / Ivy
package liquibase.util;
import java.util.*;
import java.util.regex.Pattern;
/**
* Various utility methods for working with strings.
*/
public class StringUtils {
private static final Pattern upperCasePattern = Pattern.compile(".*[A-Z].*");
private static final Pattern lowerCasePattern = Pattern.compile(".*[a-z].*");
public static String trimToEmpty(String string) {
if (string == null) {
return "";
}
return string.trim();
}
public static String trimToNull(String string) {
if (string == null) {
return null;
}
String returnString = string.trim();
if (returnString.length() == 0) {
return null;
} else {
return returnString;
}
}
/**
* Removes any comments from multiple line SQL using {@link #stripComments(String)}
* and then extracts each individual statement using {@link #splitSQL(String, String)}.
*
* @param multiLineSQL A String containing all the SQL statements
* @param stripComments If true then comments will be stripped, if false then they will be left in the code
*/
public static String[] processMutliLineSQL(String multiLineSQL, boolean stripComments, boolean splitStatements, String endDelimiter) {
StringClauses parsed = SqlParser.parse(multiLineSQL, true, !stripComments);
List returnArray = new ArrayList();
StringBuilder currentString = new StringBuilder();
String previousPiece = null;
boolean previousDelimiter = false;
for (Object piece : parsed.toArray(true)) {
if (splitStatements && piece instanceof String && isDelimiter((String) piece, previousPiece, endDelimiter)) {
String trimmedString = StringUtils.trimToNull(currentString.toString());
if (trimmedString != null) {
returnArray.add(trimmedString);
}
currentString = new StringBuilder();
previousDelimiter = true;
} else {
if (!previousDelimiter || StringUtils.trimToNull((String) piece) != null) { //don't include whitespace after a delimiter
if (!currentString.toString().equals("") || StringUtils.trimToNull((String) piece) != null) { //don't include whitespace before the statement
currentString.append(piece);
}
}
previousDelimiter = false;
}
previousPiece = (String) piece;
}
String trimmedString = StringUtils.trimToNull(currentString.toString());
if (trimmedString != null) {
returnArray.add(trimmedString);
}
return returnArray.toArray(new String[returnArray.size()]);
}
protected static boolean isDelimiter(String piece, String previousPiece, String endDelimiter) {
if (endDelimiter == null) {
return piece.equals(";") || ((piece.equalsIgnoreCase("go") || piece.equals("/")) && (previousPiece == null || previousPiece.endsWith("\n")));
} else {
if (endDelimiter.length() == 1) {
return piece.toLowerCase().equalsIgnoreCase(endDelimiter.toLowerCase());
} else {
return piece.toLowerCase().matches(endDelimiter.toLowerCase()) || (previousPiece+piece).toLowerCase().matches("[\\s\n\r]*"+endDelimiter.toLowerCase());
}
}
}
/**
* Splits a (possible) multi-line SQL statement along ;'s and "go"'s.
*/
public static String[] splitSQL(String multiLineSQL, String endDelimiter) {
return processMutliLineSQL(multiLineSQL, false, true, endDelimiter);
}
/**
* Searches through a String which contains SQL code and strips out
* any comments that are between \/**\/ or anything that matches
* SP--SP\n (to support the ANSI standard commenting of --
* at the end of a line).
*
* @return The String without the comments in
*/
public static String stripComments(String multiLineSQL) {
return SqlParser.parse(multiLineSQL, true, false).toString().trim();
}
public static String join(Object[] array, String delimiter, StringUtilsFormatter formatter) {
if (array == null) {
return null;
}
return join(Arrays.asList(array), delimiter, formatter);
}
public static String join(String[] array, String delimiter) {
return join(Arrays.asList(array), delimiter);
}
public static String join(Collection collection, String delimiter) {
return join(collection, delimiter, new ToStringFormatter());
}
public static String join(Collection collection, String delimiter, StringUtilsFormatter formatter) {
if (collection == null) {
return null;
}
if (collection.size() == 0) {
return "";
}
StringBuffer buffer = new StringBuffer();
for (Object val : collection) {
buffer.append(formatter.toString(val)).append(delimiter);
}
String returnString = buffer.toString();
return returnString.substring(0, returnString.length() - delimiter.length());
}
public static String join(Collection collection, String delimiter, StringUtilsFormatter formatter, boolean sorted) {
if (sorted) {
TreeSet sortedSet = new TreeSet();
for (Object obj : collection) {
sortedSet.add(formatter.toString(obj));
}
return join(sortedSet, delimiter);
}
return join(collection, delimiter, formatter);
}
public static String join(Collection collection, String delimiter, boolean sorted) {
if (sorted) {
return join(new TreeSet(collection), delimiter);
} else {
return join(collection, delimiter);
}
}
public static String join(Map map, String delimiter) {
return join(map, delimiter, new ToStringFormatter());
}
public static String join(Map map, String delimiter, StringUtilsFormatter formatter) {
List list = new ArrayList();
for (Map.Entry entry : (Set) map.entrySet()) {
list.add(entry.getKey().toString()+"="+formatter.toString(entry.getValue()));
}
return join(list, delimiter);
}
public static List splitAndTrim(String s, String regex) {
if (s == null) {
return null;
}
List returnList = new ArrayList();
for (String string : s.split(regex)) {
returnList.add(string.trim());
}
return returnList;
}
public static String repeat(String string, int times) {
String returnString = "";
for (int i=0; i 0x7F) {
out.append("&#");
out.append(Integer.toString(c, 10));
out.append(';');
} else {
out.append(c);
}
}
return out.toString();
}
public static String pad(String value, int length) {
value = StringUtils.trimToEmpty(value);
if (value.length() >= length) {
return value;
}
return value + StringUtils.repeat(" ", length - value.length());
}
/**
* Null-safe check if string is empty.
*
* @param value String to be checked
* @return true if String is null or empty
*/
public static boolean isEmpty(String value) {
return value == null || value.length() == 0;
}
/**
* Null-safe check if string is not empty
*
* @param value String to be checked
* @return true if string is not null and not empty (length > 0)
*/
public static boolean isNotEmpty(String value) {
return !isEmpty(value);
}
/**
* Checks if value starts with startsWith.
* @param value
* @param startsWith
* @return true if value starts with startsWith, otherwise false. If any of arguments is null returns false
*/
public static boolean startsWith(String value, String startsWith) {
if(value == null || startsWith == null){
return false;
}
return value.startsWith(startsWith);
}
public static boolean isWhitespace(CharSequence string) {
if (string == null) {
return true;
}
return StringUtils.trimToNull(string.toString()) == null;
}
public static interface StringUtilsFormatter {
public String toString(Type obj);
}
public static class ToStringFormatter implements StringUtilsFormatter {
@Override
public String toString(Object obj) {
if (obj == null) {
return null;
}
return obj.toString();
}
}
public static String limitSize(String string, int maxLength) {
if (string.length() > maxLength) {
return string.substring(0, maxLength - 3) + "...";
}
return string;
}
/**
* From commonslang3 -> StringUtils
* Gets a substring from the specified String avoiding exceptions.
*
* A negative start position can be used to start/end {@code n}
* characters from the end of the String.
*
* The returned substring starts with the character in the {@code start}
* position and ends before the {@code end} position. All position counting is
* zero-based -- i.e., to start at the beginning of the string use
* {@code start = 0}. Negative start and end positions can be used to
* specify offsets relative to the end of the String.
*
* If {@code start} is not strictly to the left of {@code end}, ""
* is returned.
*
*
* StringUtils.substring(null, *, *) = null
* StringUtils.substring("", * , *) = "";
* StringUtils.substring("abc", 0, 2) = "ab"
* StringUtils.substring("abc", 2, 0) = ""
* StringUtils.substring("abc", 2, 4) = "c"
* StringUtils.substring("abc", 4, 6) = ""
* StringUtils.substring("abc", 2, 2) = ""
* StringUtils.substring("abc", -2, -1) = "b"
* StringUtils.substring("abc", -4, 2) = "ab"
*
*
* @param str the String to get the substring from, may be null
* @param start the position to start from, negative means
* count back from the end of the String by this many characters
* @param end the position to end at (exclusive), negative means
* count back from the end of the String by this many characters
* @return substring from start position to end position,
* {@code null} if null String input
*/
public static String substring(final String str, int start, int end) {
if (str == null) {
return null;
}
// handle negatives
if (end < 0) {
end = str.length() + end; // remember end is negative
}
if (start < 0) {
start = str.length() + start; // remember start is negative
}
// check length next
if (end > str.length()) {
end = str.length();
}
// if start is greater than end, return ""
if (start > end) {
return "";
}
if (start < 0) {
start = 0;
}
if (end < 0) {
end = 0;
}
return str.substring(start, end);
}
}
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