001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.utils;
014
015import java.io.*;
016
017import org.apache.juneau.*;
018import org.apache.juneau.http.*;
019import org.apache.juneau.json.*;
020import org.apache.juneau.serializer.*;
021
022/**
023 * A serializer/object pair used for delayed object serialization.
024 * 
025 * <p>
026 * Useful in certain conditions such as logging when you don't want to needlessly serialize objects.
027 * 
028 * <p>
029 * Instances of this method are created by the {@link WriterSerializer#toStringObject(Object)} method.
030 * 
031 * <h5 class='section'>Example:</h5>
032 * <p class='bcode'>
033 *    <jc>// The POJO will not be serialized unless DEBUG is enabled.</jc>
034 *    logger.log(<jsf>DEBUG</jsf>, <js>"Object contents are: {0}"</js>, JsonSerializer.<jsf>DEFAULT</jsf>.toObjectString(myPojo));
035 * </p>
036 */
037public class StringObject implements CharSequence, Writable {
038
039   private final WriterSerializer s;
040   private final Object o;
041   private String results;
042
043   /**
044    * Constructor.
045    * 
046    * @param s The serializer to use to serialize the object.
047    * @param o The object to be serialized.
048    */
049   public StringObject(WriterSerializer s, Object o) {
050      this.s = s;
051      this.o = o;
052   }
053
054   /**
055    * Constructor with default serializer {@link JsonSerializer#DEFAULT_LAX}
056    * 
057    * @param o The object to be serialized.
058    */
059   public StringObject(Object o) {
060      this(JsonSerializer.DEFAULT_LAX, o);
061   }
062
063   @Override /* Object */
064   public String toString() {
065      if (results == null)
066         results = s.toString(o);
067      return results;
068   }
069
070   @Override /* CharSequence */
071   public int length() {
072      return toString().length();
073   }
074
075   @Override /* CharSequence */
076   public char charAt(int index) {
077      return toString().charAt(index);
078   }
079
080   @Override /* CharSequence */
081   public CharSequence subSequence(int start, int end) {
082      return toString().subSequence(start, end);
083   }
084
085   @Override /* Writable */
086   public Writer writeTo(Writer w) throws IOException {
087      try {
088         s.serialize(o, w);
089         return w;
090      } catch (SerializeException e) {
091         throw new IOException(e);
092      }
093   }
094
095   @Override /* Writable */
096   public MediaType getMediaType() {
097      return s.getMediaTypes()[0];
098   }
099}