Issue checkstyle#3034: FileText should not extends AbstractList

src/main/java/com/puppycrawl/tools/checkstyle/DetailNodeTreeStringPrinter.java

@@ -168,8 +168,6 @@ private static String getIndentation(DetailNode node) {
      * @throws IOException if the file could not be read.
      */
     private static DetailNode parseFile(File file) throws IOException {
-        // Details: https://github.com/checkstyle/checkstyle/issues/3034
-        //noinspection MismatchedQueryAndUpdateOfCollection
         final FileText text = new FileText(file.getAbsoluteFile(),
             System.getProperty("file.encoding", "UTF-8"));
         return parseJavadocAsDetailNode(text.getFullText().toString());

src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java

@@ -26,7 +26,6 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Locale;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -166,16 +165,15 @@ public void setupChild(Configuration childConf)
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) throws CheckstyleException {
+    protected void processFiltered(File file, FileText fileText) throws CheckstyleException {
         // check if already checked and passed the file
         if (CommonUtils.matchesFileExtension(file, getFileExtensions())) {
             final String msg = "%s occurred during the analysis of file %s.";
             final String fileName = file.getPath();
             try {
                 if (!ordinaryChecks.isEmpty()
                         || !commentChecks.isEmpty()) {
-                    final FileText text = FileText.fromLines(file, lines);
-                    final FileContents contents = new FileContents(text);
+                    final FileContents contents = new FileContents(fileText);
                     final DetailAST rootAST = parse(contents);
 
                     if (!ordinaryChecks.isEmpty()) {

src/main/java/com/puppycrawl/tools/checkstyle/api/AbstractFileSetCheck.java

@@ -21,7 +21,6 @@
 
 import java.io.File;
 import java.util.Arrays;
-import java.util.List;
 import java.util.SortedSet;
 
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
@@ -48,10 +47,10 @@ public abstract class AbstractFileSetCheck
     /**
      * Called to process a file that matches the specified file extensions.
      * @param file the file to be processed
-     * @param lines an immutable list of the contents of the file.
+     * @param fileText the contents of the file.
      * @throws CheckstyleException if error condition within Checkstyle occurs.
      */
-    protected abstract void processFiltered(File file, List<String> lines)
+    protected abstract void processFiltered(File file, FileText fileText)
             throws CheckstyleException;
 
     @Override
@@ -70,12 +69,12 @@ public void beginProcessing(String charset) {
     }
 
     @Override
-    public final SortedSet<LocalizedMessage> process(File file, List<String> lines)
+    public final SortedSet<LocalizedMessage> process(File file, FileText fileText)
             throws CheckstyleException {
         messageCollector.reset();
         // Process only what interested in
         if (CommonUtils.matchesFileExtension(file, fileExtensions)) {
-            processFiltered(file, lines);
+            processFiltered(file, fileText);
         }
         return messageCollector.getMessages();
     }

src/main/java/com/puppycrawl/tools/checkstyle/api/FileContents.java

@@ -77,7 +77,7 @@ public final class FileContents implements CommentListener {
     @Deprecated
     public FileContents(String filename, String... lines) {
         fileName = filename;
-        text = FileText.fromLines(new File(filename), Arrays.asList(lines));
+        text = new FileText(new File(filename), Arrays.asList(lines));
     }
 
     /**

src/main/java/com/puppycrawl/tools/checkstyle/api/FileSetCheck.java

@@ -20,7 +20,6 @@
 package com.puppycrawl.tools.checkstyle.api;
 
 import java.io.File;
-import java.util.List;
 import java.util.SortedSet;
 
 /**
@@ -68,11 +67,11 @@ public interface FileSetCheck
      * </p>
      *
      * @param file the file to be processed
-     * @param lines an immutable list of the contents of the file.
+     * @param fileText the contents of the file.
      * @return the sorted set of messages to be logged.
      * @throws CheckstyleException if error condition within Checkstyle occurs
      */
-    SortedSet<LocalizedMessage> process(File file, List<String> lines) throws CheckstyleException;
+    SortedSet<LocalizedMessage> process(File file, FileText fileText) throws CheckstyleException;
 
     /**
      * Called when all the files have been processed. This is the time to

src/main/java/com/puppycrawl/tools/checkstyle/api/FileText.java

@@ -31,7 +31,6 @@
 import java.nio.charset.CharsetDecoder;
 import java.nio.charset.CodingErrorAction;
 import java.nio.charset.UnsupportedCharsetException;
-import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -44,15 +43,12 @@
  * Represents the text contents of a file of arbitrary plain text type.
  * <p>
  * This class will be passed to instances of class FileSetCheck by
- * Checker. It implements a string list to ensure backwards
- * compatibility, but can be extended in the future to allow more
- * flexible, more powerful or more efficient handling of certain
- * situations.
+ * Checker.
  * </p>
  *
  * @author Martin von Gagern
  */
-public final class FileText extends AbstractList<String> {
+public final class FileText {
 
     /**
      * The number of characters to read in one go.
@@ -171,7 +167,7 @@ public FileText(FileText fileText) {
      * @param lines the lines of the text, without terminators
      * @throws NullPointerException if the lines array is null
      */
-    private FileText(File file, List<String> lines) {
+    public FileText(File file, List<String> lines) {
         final StringBuilder buf = new StringBuilder();
         for (final String line : lines) {
             buf.append(line).append('\n');
@@ -215,30 +211,6 @@ private static String readFile(final File inputFile, final CharsetDecoder decode
         return buf.toString();
     }
 
-    /**
-     * Compatibility conversion.
-     *
-     * <p>This method can be used to convert the arguments passed to
-     * {@link FileSetCheck#process(File,List)} to a FileText
-     * object. If the list of lines already is a FileText, it is
-     * returned as is. Otherwise, a new FileText is constructed by
-     * joining the lines using line feed characters.
-     *
-     * @param file the name of the file
-     * @param lines the lines of the text, without terminators
-     * @return an object representing the denoted text file
-     */
-    public static FileText fromLines(File file, List<String> lines) {
-        final FileText fileText;
-        if (lines instanceof FileText) {
-            fileText = (FileText) lines;
-        }
-        else {
-            fileText = new FileText(file, lines);
-        }
-        return fileText;
-    }
-
     /**
      * Get the name of the file.
      * @return an object containing the name of the file
@@ -264,6 +236,14 @@ public CharSequence getFullText() {
         return fullText;
     }
 
+    /**
+     * Returns a list of lines.
+     * @return a list of all lines of the file
+     */
+    public List<String> getLines() {
+        return new ArrayList<>(Arrays.asList(lines));
+    }
+
     /**
      * Returns an array of all lines.
      * {@code text.toLinesArray()} is equivalent to
@@ -321,7 +301,6 @@ public LineColumn lineColumn(int pos) {
      * @param lineNo the number of the line to get, starting at zero
      * @return the line with the given number
      */
-    @Override
     public String get(final int lineNo) {
         return lines[lineNo];
     }
@@ -330,7 +309,6 @@ public String get(final int lineNo) {
      * Counts the lines of the text.
      * @return the number of lines in the text
      */
-    @Override
     public int size() {
         return lines.length;
     }

src/main/java/com/puppycrawl/tools/checkstyle/checks/NewlineAtEndOfFileCheck.java

@@ -22,11 +22,11 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.util.List;
 import java.util.Locale;
 
 import com.google.common.io.Closeables;
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 
 /**
  * <p>
@@ -75,7 +75,7 @@ public class NewlineAtEndOfFileCheck
     private LineSeparatorOption lineSeparator = LineSeparatorOption.SYSTEM;
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
         // Cannot use lines as the line separators have been removed!
         try {
             final RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r");

src/main/java/com/puppycrawl/tools/checkstyle/checks/TranslationCheck.java

@@ -27,7 +27,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 import java.util.Properties;
@@ -46,6 +45,7 @@
 import com.google.common.io.Closeables;
 import com.puppycrawl.tools.checkstyle.Definitions;
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 import com.puppycrawl.tools.checkstyle.api.LocalizedMessage;
 import com.puppycrawl.tools.checkstyle.api.MessageDispatcher;
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
@@ -241,7 +241,7 @@ public void beginProcessing(String charset) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
         // We just collecting files for processing at finishProcessing()
         filesToProcess.add(file);
     }

src/main/java/com/puppycrawl/tools/checkstyle/checks/UniquePropertiesCheck.java

@@ -32,6 +32,7 @@
 import com.google.common.collect.Multiset;
 import com.google.common.collect.Multiset.Entry;
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 
 /**
  * Checks the uniqueness of property keys (left from equal sign) in the
@@ -63,7 +64,7 @@ public UniquePropertiesCheck() {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
         final UniqueProperties properties = new UniqueProperties();
 
         try {
@@ -84,6 +85,7 @@ protected void processFiltered(File file, List<String> lines) {
         for (Entry<String> duplication : properties
                 .getDuplicatedKeys().entrySet()) {
             final String keyName = duplication.getElement();
+            final List<String> lines = fileText.getLines();
             final int lineNumber = getLineNumber(lines, keyName);
             // Number of occurrences is number of duplications + 1
             log(lineNumber, MSG_KEY, keyName, duplication.getCount() + 1);

src/main/java/com/puppycrawl/tools/checkstyle/checks/header/HeaderCheck.java

@@ -23,6 +23,8 @@
 import java.util.Arrays;
 import java.util.List;
 
+import com.puppycrawl.tools.checkstyle.api.FileText;
+
 /**
  * Checks the header of the source against a fixed header file.
  * In default configuration,if header is not specified,
@@ -88,7 +90,8 @@ public void setIgnoreLines(int... list) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
+        final List<String> lines = fileText.getLines();
         if (getHeaderLines().size() > lines.size()) {
             log(1, MSG_MISSING);
         }

src/main/java/com/puppycrawl/tools/checkstyle/checks/header/RegexpHeaderCheck.java

@@ -26,6 +26,7 @@
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
+import com.puppycrawl.tools.checkstyle.api.FileText;
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
 
 /**
@@ -77,8 +78,9 @@ public void setMultiLines(int... list) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
         final int headerSize = getHeaderLines().size();
+        final List<String> lines = fileText.getLines();
         final int fileSize = lines.size();
 
         if (headerSize - multiLines.length > fileSize) {

src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/JavadocPackageCheck.java

@@ -21,10 +21,10 @@
 
 import java.io.File;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Set;
 
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 
 /**
  * Checks that all packages have a package documentation. See the documentation
@@ -67,7 +67,7 @@ public void beginProcessing(String charset) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
+    protected void processFiltered(File file, FileText fileText) {
         // Check if already processed directory
         final File dir = file.getParentFile();
         if (!directoriesChecked.contains(dir)) {

src/main/java/com/puppycrawl/tools/checkstyle/checks/regexp/RegexpMultilineCheck.java

@@ -20,7 +20,6 @@
 package com.puppycrawl.tools.checkstyle.checks.regexp;
 
 import java.io.File;
-import java.util.List;
 import java.util.regex.Pattern;
 
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
@@ -63,8 +62,8 @@ public void beginProcessing(String charset) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
-        detector.processLines(FileText.fromLines(file, lines));
+    protected void processFiltered(File file, FileText fileText) {
+        detector.processLines(fileText);
     }
 
     /**

src/main/java/com/puppycrawl/tools/checkstyle/checks/regexp/RegexpOnFilenameCheck.java

@@ -21,11 +21,11 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.util.List;
 import java.util.regex.Pattern;
 
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
 
 /**
@@ -248,7 +248,7 @@ public void init() {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) throws CheckstyleException {
+    protected void processFiltered(File file, FileText fileText) throws CheckstyleException {
         final String fileName = getFileName(file);
         final String folderPath = getFolderPath(file);
 

src/main/java/com/puppycrawl/tools/checkstyle/checks/regexp/RegexpSinglelineCheck.java

@@ -20,9 +20,9 @@
 package com.puppycrawl.tools.checkstyle.checks.regexp;
 
 import java.io.File;
-import java.util.List;
 
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
+import com.puppycrawl.tools.checkstyle.api.FileText;
 
 /**
  * Implementation of a check that looks for a single line in any file type.
@@ -60,8 +60,8 @@ public void beginProcessing(String charset) {
     }
 
     @Override
-    protected void processFiltered(File file, List<String> lines) {
-        detector.processLines(lines);
+    protected void processFiltered(File file, FileText fileText) {
+        detector.processLines(fileText.getLines());
     }
 
     /**