Initial commit

src/main/java/net/knarcraft/paidsigns/utility/Tokenizer.java

@@ -0,0 +1,99 @@
+package net.knarcraft.paidsigns.utility;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A tokenizer for being able to support quotes in commands
+ */
+public class Tokenizer {
+
+    /**
+     * Tokenizes a string
+     *
+     * @param input <p>A string.</p>
+     * @return <p>A list of tokens.</p>
+     */
+    public static List<String> tokenize(String input) {
+        List<String> tokens = new ArrayList<>();
+        boolean startedQuote = false;
+        StringBuilder currentToken = new StringBuilder();
+        for (int index = 0; index < input.length(); index++) {
+            char character = input.charAt(index);
+            switch (character) {
+                case ' ':
+                    if (tokenizeSpace(startedQuote, currentToken, tokens)) {
+                        currentToken = new StringBuilder();
+                    }
+                    break;
+                case '"':
+                    if (startedQuote) {
+                        //This quote signifies the end of the argument
+                        if (isNotEmpty(currentToken)) {
+                            tokens.add(currentToken.toString());
+                            currentToken = new StringBuilder();
+                        }
+                        startedQuote = false;
+                    } else {
+                        //This quote signifies the start of the argument
+                        startedQuote = true;
+                        currentToken = new StringBuilder();
+                    }
+                    break;
+                default:
+                    tokenizeNormalCharacter(currentToken, character, input.length(), index, tokens);
+                    break;
+            }
+        }
+        return tokens;
+    }
+
+    /**
+     * Adds a normal character to the token. Adds the current token to tokens if at the end of the input
+     *
+     * @param currentToken <p>The string builder containing the current token.</p>
+     * @param character    <p>The character found in the input.</p>
+     * @param inputLength  <p>The length of the given input</p>
+     * @param index        <p>The index of the read character.</p>
+     * @param tokens       <p>The list of processed tokens.</p>
+     */
+    private static void tokenizeNormalCharacter(StringBuilder currentToken, char character, int inputLength, int index,
+                                                List<String> tokens) {
+        currentToken.append(character);
+        if (index == inputLength - 1) {
+            tokens.add(currentToken.toString());
+        }
+    }
+
+    /**
+     * Tokenizes a space character
+     *
+     * @param startedQuote <p>Whether this space is inside a pair of quotes.</p>
+     * @param currentToken <p>The string builder containing the current token.</p>
+     * @param tokens       <p>The list of processed tokens.</p>
+     * @return <p>True if the token is finished.</p>
+     */
+    private static boolean tokenizeSpace(boolean startedQuote, StringBuilder currentToken, List<String> tokens) {
+        if (!startedQuote) {
+            //If not inside "", a space marks the end of a parameter
+            if (isNotEmpty(currentToken)) {
+                tokens.add(currentToken.toString());
+            }
+            return true;
+        } else {
+            currentToken.append(' ');
+            return false;
+        }
+    }
+
+    /**
+     * Checks whether a string builder is empty
+     *
+     * @param builder <p>The string builder to check.</p>
+     * @return <p>True if the string builder is non empty.</p>
+     */
+    private static boolean isNotEmpty(StringBuilder builder) {
+        return !builder.toString().trim().equals("");
+    }
+
+}