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NextReports Engine is a lightweight Java platform development library which
can be used to run NextReports inside your applications.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package ro.nextreports.engine.queryexec.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
/**
* @author Decebal Suiu
*/
public class StringUtil {
private static final String SPACE = " ";
private static final String COMMENT_MULTILINE_START = "/*";
private static final String COMMENT_MULTILINE_END = "*/";
private static final String COMMENT_SINGLELINE_START = "//";
/**
* Remove all blank lines from a string. A blank line is defined to be a
* line where the only characters are whitespace. We always ensure that the
* line contains a newline at the end.
*
* @param text
* The string to strip blank lines from
* @return The blank line stripped reply
*/
public static String stripBlankLines(String text) {
if (text == null) {
return null;
}
try {
StringBuffer output = new StringBuffer();
BufferedReader in = new BufferedReader(new StringReader(text));
boolean doneOneLine = false;
while (true) {
String line = in.readLine();
if (line == null) {
break;
}
if (line.trim().length() > 0) {
output.append(line);
output.append('\n');
doneOneLine = true;
}
}
if (!doneOneLine) {
output.append('\n');
}
return output.toString();
} catch (IOException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Remove all newline characters from a string.
*
* @param text
* The string to strip newline characters from
* @return The stripped reply
*/
public static String stripNewlines(String text) {
if (text == null) {
return null;
}
try {
StringBuffer output = new StringBuffer();
BufferedReader in = new BufferedReader(new StringReader(text));
while (true) {
String line = in.readLine();
if (line == null) {
break;
}
output.append(line);
output.append(SPACE);
}
output.append('\n');
return output.toString();
} catch (IOException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Remove all the multi-line comments from a block of text
* @param text The text to remove multi-line comments from
* @return The multi-line comment free text
*/
public static String stripMultiLineComments(String text) {
if (text == null) {
return null;
}
try {
StringBuffer output = new StringBuffer();
// Comment rules:
/*/ This is still a comment
/* /* */ // Comments do not nest
// /* */ This is in a comment
/* // */ // The second // is needed to make this a comment.
// First we strip multi line comments. I think this is important:
boolean inMultiLine = false;
BufferedReader in = new BufferedReader(new StringReader(text));
while (true) {
String line = in.readLine();
if (line == null) {
break;
}
if (!inMultiLine) {
// We are not in a multi-line comment, check for a start
int cstart = line.indexOf(COMMENT_MULTILINE_START);
if (cstart >= 0) {
// This could be a MLC on one line ...
int cend = line.indexOf(COMMENT_MULTILINE_END, cstart + COMMENT_MULTILINE_START.length());
if (cend >= 0) {
// A comment that starts and ends on one line
// BUG: you can have more than 1 multi-line comment on a line
line = line.substring(0, cstart) + SPACE + line.substring(cend + COMMENT_MULTILINE_END.length());
} else {
// A real multi-line comment
inMultiLine = true;
line = line.substring(0, cstart) + SPACE;
}
} else {
// We are not in a multi line comment and we havn't
// started one so we are going to ignore closing
// comments even if they exist.
}
} else {
// We are in a multi-line comment, check for the end
int cend = line.indexOf(COMMENT_MULTILINE_END);
if (cend >= 0) {
// End of comment
line = line.substring(cend + COMMENT_MULTILINE_END.length());
inMultiLine = false;
} else {
// The comment continues
line = SPACE;
}
}
output.append(line);
output.append('\n');
}
return output.toString();
} catch (IOException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Remove all the single-line comments from a block of text
* @param text The text to remove single-line comments from
* @return The single-line comment free text
*/
public static String stripSingleLineComments(String text) {
if (text == null) {
return null;
}
try {
StringBuffer output = new StringBuffer();
// First we strip multi line comments. I think this is important:
BufferedReader in = new BufferedReader(new StringReader(text));
while (true) {
String line = in.readLine();
if (line == null) {
break;
}
int cstart = line.indexOf(COMMENT_SINGLELINE_START);
if (cstart >= 0) {
line = line.substring(0, cstart);
}
output.append(line);
output.append('\n');
}
return output.toString();
} catch (IOException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Remove any leading or trailing spaces from a line of code.
* This function could be improved by making it strip unnecessary double
* spaces, but since we would need to leave double spaces inside strings
* this is not simple and since the benefit is small, we'll leave it for now
* @param text The javascript program to strip spaces from.
* @return The stripped program
*/
public static String trimLines(String text) {
if (text == null) {
return null;
}
try {
StringBuffer output = new StringBuffer();
// First we strip multi line comments. I think this is important:
BufferedReader in = new BufferedReader(new StringReader(text));
while (true) {
String line = in.readLine();
if (line == null) {
break;
}
output.append(line.trim());
output.append('\n');
}
return output.toString();
} catch (IOException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Replaces all instances of the tab character in text with
* the spaces.
*
* @param text The java.lang.String in which to replace tabs
* with spaces.
* @return A java.lang.String just like text,
* but with spaces instead of tabs.
*/
public static String replaceTabsWithSpaces(String text, int tabSize) {
String tabText = "";
for (int i = 0; i < tabSize; i++) {
tabText += " ";
}
return text.replaceAll("\t", " ");
}
/**
* Only one space between words.
*/
public static String deleteExcededSpaces(String text) {
int size = text.length();
StringBuffer sb = new StringBuffer();
for (int i = 0; i < size; i++) {
char ch = text.charAt(i);
if (ch == ' ') {
if (i > 0) {
char ch2 = text.charAt(i-1);
if ((ch2 != ' ') && (i < size-1) && (!text.substring(i+1).trim().equals(""))) {
sb.append(ch);
}
}
} else {
sb.append(ch);
}
}
return sb.toString();
}
}