Use eclipse util method to detect line separator

Author: ParkerM

Diff for: spring-javaformat/spring-javaformat-formatter-eclipse-jdk11/pom.xml

@@ -173,6 +173,7 @@
 								<option>-keep class org.eclipse.jdt.core.formatter.** {*;}</option>
 								<option>-keep class org.eclipse.jdt.internal.formatter.** {*;}</option>
 								<option>-keep class org.eclipse.jface.text.Document {*;}</option>
+								<option>-keep class org.eclipse.jface.text.TextUtilities {*;}</option>
 								<option>-keep class
 									org.eclipse.jdt.internal.compiler.parser.TerminalTokens {*;}</option>
 								<option>-keep class org.eclipse.jdt.core.dom.TagElement {*;}</option>

Diff for: spring-javaformat/spring-javaformat-formatter-eclipse-jdk8/pom.xml

@@ -173,6 +173,7 @@
 								<option>-keep class org.eclipse.jdt.core.formatter.** {*;}</option>
 								<option>-keep class org.eclipse.jdt.internal.formatter.** {*;}</option>
 								<option>-keep class org.eclipse.jface.text.Document {*;}</option>
+								<option>-keep class org.eclipse.jface.text.TextUtilities {*;}</option>
 								<option>-keep class
 									org.eclipse.jdt.internal.compiler.parser.TerminalTokens {*;}</option>
 								<option>-keep class org.eclipse.jdt.core.dom.TagElement {*;}</option>

Diff for: spring-javaformat/spring-javaformat-formatter/src/main/java/io/spring/javaformat/formatter/Formatter.java

@@ -17,10 +17,9 @@
 package io.spring.javaformat.formatter;
 
 import java.util.Map;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.TextUtilities;
 import org.eclipse.text.edits.TextEdit;
 
 import io.spring.javaformat.config.JavaBaseline;
@@ -58,11 +57,6 @@ public class Formatter {
 	 */
 	private static final int DEFAULT_INDENTATION_LEVEL = 0;
 
-	/**
-	 * Pattern that matches all line separators into named-capturing group "sep".
-	 */
-	private static final Pattern LINE_SEPARATOR_PATTERN = Pattern.compile("(?<sep>(\r\n|\r|\n))");
-
 	/**
 	 * The default line separator.
 	 */
@@ -131,7 +125,7 @@ public TextEdit format(String source, int offset, int length, String lineSeparat
 	public TextEdit format(int kind, String source, int offset, int length, int indentationLevel,
 			String lineSeparator) {
 		if (lineSeparator == null) {
-			lineSeparator = detectLineSeparator(source);
+			lineSeparator = TextUtilities.determineLineDelimiter(source, DEFAULT_LINE_SEPARATOR);
 		}
 		return this.delegate.format(kind, source, offset, length, indentationLevel, lineSeparator);
 	}
@@ -159,7 +153,7 @@ public TextEdit format(String source, IRegion[] regions, String lineSeparator) {
 
 	public TextEdit format(int kind, String source, IRegion[] regions, int indentationLevel, String lineSeparator) {
 		if (lineSeparator == null) {
-			lineSeparator = detectLineSeparator(source);
+			lineSeparator = TextUtilities.determineLineDelimiter(source, DEFAULT_LINE_SEPARATOR);
 		}
 		return this.delegate.format(kind, source, regions, indentationLevel, lineSeparator);
 	}
@@ -172,17 +166,4 @@ public void setOptions(Map<String, String> options) {
 		this.delegate.setOptions(options);
 	}
 
-	private String detectLineSeparator(String contents) {
-		Matcher matcher = LINE_SEPARATOR_PATTERN.matcher(contents);
-		if (!matcher.find()) {
-			return DEFAULT_LINE_SEPARATOR;
-		}
-		String firstMatch = matcher.group("sep");
-		while (matcher.find()) {
-			if (!matcher.group("sep").equals(firstMatch)) {
-				return DEFAULT_LINE_SEPARATOR;
-			}
-		}
-		return firstMatch;
-	}
 }