// Test quotes are escaped.
    assertEquals(""test"", xmlAttributeEscaper.escape("\"test\""));
    assertEquals("'test'", xmlAttributeEscaper.escape("\'test'"));
    // Test all escapes
    assertEquals(
        "a&quot;b&lt;c&gt;d&amp;e&quot;f&apos;", xmlAttributeEscaper.escape("a\"b<c>d&e\"f'"));
    // Test '\t', '\n' and '\r' are escaped.

    }
  }

  public void testFalsePositivesForNextEscapedIndex() {
    UnicodeEscaper e =
        new UnicodeEscaper() {
          // Canonical escaper method that only escapes lower case ASCII letters.
          @Override
          protected char @Nullable [] escape(int cp) {
            return ('a' <= cp && cp <= 'z') ? new char[] {Character.toUpperCase((char) cp)} : null;
          }

    }
  }

  public void testFalsePositivesForNextEscapedIndex() {
    UnicodeEscaper e =
        new UnicodeEscaper() {
          // Canonical escaper method that only escapes lower case ASCII letters.
          @Override
          protected char @Nullable [] escape(int cp) {
            return ('a' <= cp && cp <= 'z') ? new char[] {Character.toUpperCase((char) cp)} : null;
          }

 * the License.
 */

/**
 * Interfaces, utilities, and simple implementations of escapers and encoders. The primary type is
 * {@link Escaper}.
 *
 * <p>Additional escapers implementations are found in the applicable packages: {@link
 * com.google.common.html.HtmlEscapers} in {@code com.google.common.html}, {@link

 *
 */
public class JsonUtil {

    /**
     * Defualt constructor.
     */
    protected JsonUtil() {
    }

    /**
     * Escapes a value as Json string.
     *
     * @param value input
     * @return escaped string.
     */
    public static String escape(final String value) {
        if (value == null) {
            return null;
        }

        char c;
        final int len = value.length();

 * As such sharing this data structure between escaper instances is the primary goal of this class.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class ArrayBasedEscaperMap {
  /**
   * Returns a new ArrayBasedEscaperMap for creating ArrayBasedCharEscaper or
   * ArrayBasedUnicodeEscaper instances.
   *
   * @param replacements a map of characters to their escaped representations
   */

 * As such sharing this data structure between escaper instances is the primary goal of this class.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class ArrayBasedEscaperMap {
  /**
   * Returns a new ArrayBasedEscaperMap for creating ArrayBasedCharEscaper or
   * ArrayBasedUnicodeEscaper instances.
   *
   * @param replacements a map of characters to their escaped representations
   */

     *   <li>' with &amp;apos;</li>
     * </ul>
     * Additionally, it strips invalid XML characters from the input string.
     *
     * @param value the input string to be escaped
     * @return the escaped XML string with invalid characters removed
     */
    public static String escapeXml(final String value) {
        return stripInvalidXMLCharacters(//
                value//

    UnicodeEscaper e = (UnicodeEscaper) urlFormParameterEscaper();
    // Verify that these are the same escaper (as documented)
    assertSame(e, urlFormParameterEscaper());
    assertBasicUrlEscaper(e);

    /*
     * Specified as safe by RFC 2396 but not by java.net.URLEncoder. These tests will start failing
     * when the escaper is made compliant with RFC 2396, but that's a good thing (just change them
     * to assertUnescaped).
     */

    assertUnicodeEscaping(e, "%F4%8F%BF%BF", '\uDBFF', '\uDFFF');

    // simple string tests
    assertEquals("", e.escape(""));
    assertEquals("safestring", e.escape("safestring"));
    assertEquals("embedded%00null", e.escape("embedded\0null"));
    assertEquals("max%EF%BF%BFchar", e.escape("max\uffffchar"));
  }

  /** Tests the various ways that the space character can be handled */
  public void testPlusForSpace() {