Add JavaDoc to 'Json' classes

java/src/org/openqa/selenium/json/Input.java

@@ -24,40 +24,61 @@
 
 /**
  * Similar to a {@link Reader} but with the ability to peek a single character ahead.
- *
- * <p>For the sake of providing a useful {@link #toString()} implementation, keeps the most recently
+ * <p>
+ * For the sake of providing a useful {@link #toString()} implementation, keeps the most recently
  * read characters in the input buffer.
  */
 class Input {
-  public static final char EOF = (char) -1;
-  // the number of chars to buffer
+  /** end-of-file indicator (0xFFFD) */
+  public static final char EOF = (char) -1; // NOTE: Produces Unicode replacement character (0xFFFD)
+  /** the number of chars to buffer */
   private static final int BUFFER_SIZE = 4096;
-  // the number of chars to remember, safe to set to 0
+  /** the number of chars to remember, safe to set to 0 */
   private static final int MEMORY_SIZE = 128;
 
   private final Reader source;
-  // a buffer used to minimize read calls and to keep the chars to remember
+  /** a buffer used to minimize read calls and to keep the chars to remember */
   private final char[] buffer;
-  // the filled area in the buffer
+  /** the filled area in the buffer */
   private int filled;
-  // the last position read in the buffer
+  /** the last position read in the buffer */
   private int position;
 
+  /**
+   * Initialize a new instance of the {@link Input} class with the specified source.
+   *
+   * @param source {@link Reader} object that supplies the input to be processed
+   */
   public Input(Reader source) {
     this.source = Require.nonNull("Source", source);
     this.buffer = new char[BUFFER_SIZE + MEMORY_SIZE];
     this.filled = 0;
     this.position = -1;
   }
 
+  /**
+   * Extract the next character from the input without consuming it.
+   *
+   * @return the next input character; {@link #EOF} if input is exhausted
+   */
   public char peek() {
     return fill() ? buffer[position + 1] : EOF;
   }
 
+  /**
+   * Read and consume the next character from the input.
+   *
+   * @return the next input character; {@link #EOF} if input is exhausted
+   */
   public char read() {
     return fill() ? buffer[++position] : EOF;
   }
 
+  /**
+   * Return a string containing the most recently consumed input characters.
+   *
+   * @return {@link String} with up to 128 consumed input characters
+   */
   @Override
   public String toString() {
     int offset;
@@ -74,6 +95,13 @@ public String toString() {
     return "Last " + length + " characters read: " + new String(buffer, offset, length);
   }
 
+  /**
+   * If all buffered input has been consumed, read the next chunk into the buffer.<br>
+   * <b>NOTE</b>: The last 128 character of consumed input is retained for debug output.
+   *
+   * @return {@code true} if new input is available; {@code false} if input is exhausted
+   * @throws UncheckedIOException if an I/O exception is encountered
+   */
   private boolean fill() {
     // do we need to fill the buffer?
     while (filled == position + 1) {

java/src/org/openqa/selenium/json/Json.java

@@ -27,34 +27,133 @@
 import java.util.List;
 import java.util.Map;
 
+/**
+ * The <b>Json</b> class is the entrypoint for the JSON processing features of the Selenium API.
+ * These features include:
+ * <ul>
+ *   <li>Built-in JSON deserialization to primitives and collections from the standard types shown below.</li>
+ *   <li>Facilities to deserialize JSON to custom data types:
+ *     <ul>
+ *       <li>Classes that declare a {@code fromJson(T)} static method, where <b>T</b> is any of the standard
+ *           types shown below.</li>
+ *       <li>Classes that declare a {@code fromJson(JsonInput)} static method.<br>
+ *           <b>NOTE</b>: Objects deserialized via a {@code fromJson} static method can be immutable.</li>
+ *       <li>Classes that declare setter methods adhering to the
+ *           <a href="https://docs.oracle.com/javase/tutorial/javabeans/writing/index.html">JavaBean</a>
+ *           specification.<br>
+ *           <b>NOTE</b>: Deserialized {@code JavaBean} objects are mutable, which may be undesirable.</li>
+ *     </ul>
+ *   </li>
+ *   <li>Built-in JSON serialization from primitives and collections from the standard types shown below.</li>
+ *   <li>Facilities to serialize custom data types to JSON:
+ *     <ul>
+ *       <li>Classes that declare a {@code toJson()} method returning a primitive or collection from
+ *           the standard types shown below.</li>
+ *       <li>Classes that declare getter methods adhering to the {@code JavaBean} specification.</li>
+ *     </ul>
+ *   </li>
+ * </ul>
+ *
+ * The standard types supported by built-in processing:
+ * <ul>
+ *   <li><b>Numeric Types</b>:<br>
+ *       {@link java.lang.Byte Byte}, {@link java.lang.Double Double}, {@link java.lang.Float Float},
+ *       {@link java.lang.Integer Integer}, {@link java.lang.Long Long}, {@link java.lang.Short Short}
+ *   </li>
+ *   <li><b>Collection Types</b>:<br>
+ *       {@link java.util.List List}, {@link java.util.Set Set}
+ *   </li>
+ *   <li><b>Standard Java Types</b>:<br>
+ *       {@link java.util.Map Map}, {@link java.lang.Boolean Boolean}, {@link java.lang.String String},
+ *       {@link java.lang.Enum Enum}, {@link java.net.URI URI}, {@link java.net.URL URL},
+ *       {@link java.util.UUID UUID}, {@link java.time.Instant Instant}, {@link java.lang.Object Object}
+ *   </li>
+ * </ul>
+ *
+ * You can serialize objects for which no explicit coercer has been specified, and the <b>Json</b> API will use a
+ * generic process to provide best-effort JSON output. For the most predictable results, though, it's best to
+ * provide a {@code toJson()} method for the <b>Json</b> API to use for serialization. This is especially beneficial
+ * for objects that contain transient properties that should be omitted from the JSON output.
+ * <p>
+ * You can deserialize objects for which no explicit handling has been defined. Note that the data type of the
+ * result will be {@code Map<String,?>}, which means that you'll need to perform type checking and casting every
+ * time you extract an entry value from the result. For this reason, it's best to declare a type-specific
+ * {@code fromJson()} method in every type you need to deserialize.
+ *
+ * @see JsonTypeCoercer
+ * @see JsonInput
+ * @see JsonOutput
+ */
 public class Json {
+  /** The value of {@code Content-Type} headers for HTTP requests and
+   * responses with JSON entities */
   public static final String JSON_UTF_8 = "application/json; charset=utf-8";
 
+  /** Specifier for {@code List<Map<String, Object>} input/output type */
   public static final Type LIST_OF_MAPS_TYPE =
-      new TypeToken<List<Map<String, Object>>>() {}.getType();
+    new TypeToken<List<Map<String, Object>>>() {}.getType();
+  /** Specifier for {@code Map<String, Object>} input/output type */
   public static final Type MAP_TYPE = new TypeToken<Map<String, Object>>() {}.getType();
+  /** Specifier for {@code Object} input/output type */
   public static final Type OBJECT_TYPE = new TypeToken<Object>() {}.getType();
 
   private final JsonTypeCoercer fromJson = new JsonTypeCoercer();
 
+  /**
+   * Serialize the specified object to JSON string representation.<br>
+   * <b>NOTE</b>: This method limits traversal of nested objects to the default
+   * {@link JsonOutput#MAX_DEPTH maximum depth}.
+   *
+   * @param toConvert the object to be serialized
+   * @return JSON string representing the specified object
+   */
   public String toJson(Object toConvert) {
     return toJson(toConvert, JsonOutput.MAX_DEPTH);
   }
 
+  /**
+   * Serialize the specified object to JSON string representation.
+   *
+   * @param toConvert the object to be serialized
+   * @param maxDepth maximum depth of nested object traversal
+   * @return JSON string representing the specified object
+   * @throws JsonException if an I/O exception is encountered
+   */
   public String toJson(Object toConvert, int maxDepth) {
     try (Writer writer = new StringWriter();
-        JsonOutput jsonOutput = newOutput(writer)) {
+         JsonOutput jsonOutput = newOutput(writer)) {
       jsonOutput.write(toConvert, maxDepth);
       return writer.toString();
     } catch (IOException e) {
       throw new JsonException(e);
     }
   }
 
+  /**
+   * Deserialize the specified JSON string into an object of the specified type.<br>
+   * <b>NOTE</b>: This method uses the {@link PropertySetting#BY_NAME BY_NAME} strategy to assign values to properties
+   * in the deserialized object.
+   *
+   * @param source serialized source as JSON string
+   * @param typeOfT data type for deserialization (class or {@link TypeToken})
+   * @return object of the specified type deserialized from [source]
+   * @param <T> result type (as specified by [typeOfT])
+   * @throws JsonException if an I/O exception is encountered
+   */
   public <T> T toType(String source, Type typeOfT) {
     return toType(source, typeOfT, PropertySetting.BY_NAME);
   }
 
+  /**
+   * Deserialize the specified JSON string into an object of the specified type.
+   *
+   * @param source serialized source as JSON string
+   * @param typeOfT data type for deserialization (class or {@link TypeToken})
+   * @param setter strategy used to assign values during deserialization
+   * @return object of the specified type deserialized from [source]
+   * @param <T> result type (as specified by [typeOfT])
+   * @throws JsonException if an I/O exception is encountered
+   */
   public <T> T toType(String source, Type typeOfT, PropertySetting setter) {
     try (StringReader reader = new StringReader(source)) {
       return toType(reader, typeOfT, setter);
@@ -63,10 +162,31 @@ public <T> T toType(String source, Type typeOfT, PropertySetting setter) {
     }
   }
 
+  /**
+   * Deserialize the JSON string supplied by the specified {@code Reader} into an object of the specified type.<br>
+   * <b>NOTE</b>: This method uses the {@link PropertySetting#BY_NAME BY_NAME} strategy to assign values to properties
+   * in the deserialized object.
+   *
+   * @param source {@link Reader} that supplies a serialized JSON string
+   * @param typeOfT data type for deserialization (class or {@link TypeToken})
+   * @return object of the specified type deserialized from [source]
+   * @param <T> result type (as specified by [typeOfT])
+   * @throws JsonException if an I/O exception is encountered
+   */
   public <T> T toType(Reader source, Type typeOfT) {
     return toType(source, typeOfT, PropertySetting.BY_NAME);
   }
 
+  /**
+   * Deserialize the JSON string supplied by the specified {@code Reader} into an object of the specified type.
+   *
+   * @param source {@link Reader} that supplies a serialized JSON string
+   * @param typeOfT data type for deserialization (class or {@link TypeToken})
+   * @param setter strategy used to assign values during deserialization
+   * @return object of the specified type deserialized from [source]
+   * @param <T> result type (as specified by [typeOfT])
+   * @throws JsonException if an I/O exception is encountered
+   */
   public <T> T toType(Reader source, Type typeOfT, PropertySetting setter) {
     if (setter == null) {
       throw new JsonException("Mechanism for setting properties must be set");
@@ -77,10 +197,26 @@ public <T> T toType(Reader source, Type typeOfT, PropertySetting setter) {
     }
   }
 
+  /**
+   * Create a new {@code JsonInput} object to traverse the JSON string supplied the specified {@code Reader}.<br>
+   * <b>NOTE</b>: The {@code JsonInput} object returned by this method uses the {@link PropertySetting#BY_NAME BY_NAME}
+   * strategy to assign values to properties objects it deserializes.
+   *
+   * @param from {@link Reader} that supplies a serialized JSON string
+   * @return {@link JsonInput} object to traverse the JSON string supplied by [from]
+   * @throws UncheckedIOException if an I/O exception occurs
+   */
   public JsonInput newInput(Reader from) throws UncheckedIOException {
     return new JsonInput(from, fromJson, PropertySetting.BY_NAME);
   }
 
+  /**
+   * Create a new {@code JsonOutput} object to produce a serialized JSON string in the specified {@code Appendable}.
+   *
+   * @param to {@link Appendable} that consumes a serialized JSON string
+   * @return {@link JsonOutput} object to product a JSON string in [to]
+   * @throws UncheckedIOException if an I/O exception occurs
+   */
   public JsonOutput newOutput(Appendable to) throws UncheckedIOException {
     return new JsonOutput(to);
   }