StringEscapePolicy.java

/*
 *
 * Copyright 2016 Wei-Ming Wu
 *
 * Licensed 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 com.github.wnameless.json.flattener;

import static java.util.Collections.unmodifiableMap;
import java.util.Collections;
import java.util.HashMap;
import org.apache.commons.text.StringEscapeUtils;
import org.apache.commons.text.translate.AggregateTranslator;
import org.apache.commons.text.translate.CharSequenceTranslator;
import org.apache.commons.text.translate.EntityArrays;
import org.apache.commons.text.translate.JavaUnicodeEscaper;
import org.apache.commons.text.translate.LookupTranslator;

/**
 * 
 * {@link StringEscapePolicy} lists all acceptable JSON string escape policy of the
 * {@link JsonFlattener}.
 * 
 * @author Wei-Ming Wu
 *
 */
public enum StringEscapePolicy implements CharSequenceTranslatorFactory {

  /**
   * Escapes all JSON special characters and Unicode.
   */
  ALL(StringEscapeUtils.ESCAPE_JSON),

  /**
   * Escapes all JSON special characters and Unicode but slash('/').
   */
  ALL_BUT_SLASH(new AggregateTranslator(
      new LookupTranslator(unmodifiableMap(new HashMap<CharSequence, CharSequence>() {
        private static final long serialVersionUID = 1L;
        {
          put("\"", "\\\"");
          put("\\", "\\\\");
        }
      })), new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE),
      JavaUnicodeEscaper.outsideOf(32, 0x7f))),

  /**
   * Escapes all JSON special characters but Unicode.
   */
  ALL_BUT_UNICODE(new AggregateTranslator(
      new LookupTranslator(unmodifiableMap(new HashMap<CharSequence, CharSequence>() {
        private static final long serialVersionUID = 1L;
        {
          put("\"", "\\\"");
          put("\\", "\\\\");
          put("/", "\\/");
        }
      })), new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE))),

  /**
   * Escapes all JSON special characters but slash('/') and Unicode.
   */
  ALL_BUT_SLASH_AND_UNICODE(new AggregateTranslator(
      new LookupTranslator(Collections.unmodifiableMap(new HashMap<CharSequence, CharSequence>() {
        private static final long serialVersionUID = 1L;
        {
          put("\"", "\\\"");
          put("\\", "\\\\");
        }
      })), new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE))),

  /**
   * Escapes all JSON special characters but slash('/') and Unicode.
   */
  DEFAULT(new AggregateTranslator(
      new LookupTranslator(unmodifiableMap(new HashMap<CharSequence, CharSequence>() {
        private static final long serialVersionUID = 1L;
        {
          put("\"", "\\\"");
          put("\\", "\\\\");
        }
      })), new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE)));

  private final CharSequenceTranslator translator;

  private StringEscapePolicy(CharSequenceTranslator translator) {
    this.translator = translator;
  }

  @Override
  public CharSequenceTranslator getCharSequenceTranslator() {
    return translator;
  }

}