Java: Add docs to GlideString (#1827)

* Address PR comments.

java/client/src/main/java/glide/api/models/GlideString.java

@@ -6,24 +6,42 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import lombok.Getter;
 
-// TODO docs for the god of docs
+/**
+ * Represents a Valkey string type. Since Valkey stores strings as <code>byte[]</code>, such strings
+ * can contain non-UTF8 compatible symbols or even arbitrary binary data BLOBs.<br>
+ * This class stores data <code>byte[]</code> too, but provides API to represent data as a {@link
+ * String} if conversion is possible.
+ *
+ * @see <a href="@see https://valkey.io/docs/topics/strings/">valkey.io</a> for more details.
+ */
 public class GlideString implements Comparable<GlideString> {
 
+    /** The Valkey string as a binary representation. */
     @Getter private byte[] bytes;
+
+    /**
+     * Stores a string when it is possible.<br>
+     * {@link String} representation of the value is only stored if conversion via {@link
+     * #canConvertToString()} is possible. The conversion is lazy, and only converted on the first
+     * call {@link #toString()}, {@link #getString()}, or {@link #canConvertToString()}.
+     */
     private String string = null;
 
     /** Flag whether possibility to convert to string was checked. */
     private final AtomicBoolean conversionChecked = new AtomicBoolean(false);
 
+    /** Constructor is private - use {@link #gs} or {@link #of} to instantiate an object. */
     private GlideString() {}
 
+    /** Create a GlideString using a {@link String}. */
     public static GlideString of(String string) {
         var res = new GlideString();
         res.string = string;
         res.bytes = string.getBytes(StandardCharsets.UTF_8);
         return res;
     }
 
+    /** Create a GlideString using a byte array. */
     public static GlideString of(byte[] bytes) {
         var res = new GlideString();
         res.bytes = bytes;
@@ -46,19 +64,23 @@ public static <ArgType> GlideString of(ArgType o) {
         }
     }
 
+    /** Create a GlideString using a {@link String}. */
     public static GlideString gs(String string) {
         return GlideString.of(string);
     }
 
+    /** Create a GlideString using a byte array. */
     public static GlideString gs(byte[] bytes) {
         return GlideString.of(bytes);
     }
 
+    /** Converts stored data to a human-friendly {@link String} if it is possible. */
     @Override
     public String toString() {
         return getString();
     }
 
+    /** Converts stored data to a human-friendly {@link String} if it is possible. */
     public String getString() {
         if (string != null) {
             return string;
@@ -70,10 +92,12 @@ public String getString() {
         return String.format("Value not convertible to string: byte[] %d", Arrays.hashCode(bytes));
     }
 
+    /** Compare with another GlideString. */
     public int compareTo(GlideString o) {
         return Arrays.compare(this.bytes, o.bytes);
     }
 
+    /** Check whether stored data could be converted to a {@link String}. */
     public boolean canConvertToString() {
         if (string != null) {
             return true;
@@ -86,7 +110,7 @@ public boolean canConvertToString() {
             synchronized (this) {
                 if (conversionChecked.get()) {
                     return false;
-                } else
+                } else {
                     try {
                         // TODO find a better way to check this
                         // Detect whether `bytes` could be represented by a `String` without data corruption
@@ -100,6 +124,7 @@ public boolean canConvertToString() {
                     } finally {
                         conversionChecked.set(true);
                     }
+                }
             }
         }
     }