* Root object type's like Person[].class, String[].class, can now be specified as the rootType and the return value will be Person[], String[], or a ClassCastException if the JSON data does not match the type.

  * `JsonIo.formatJson()` three parameter version removed. Use the one (1) parameter API that takes the JSON to format. It runs much faster, as it no longer deserializes/serializes, but walks the JSON `String` directly.

Author: jdereg

README.md

@@ -24,15 +24,15 @@ ___
 To include in your project:
 ##### Gradle
 ```groovy
-implementation 'com.cedarsoftware:json-io:4.29.0'
+implementation 'com.cedarsoftware:json-io:4.30.0'
 ```
 
 ##### Maven
 ```xml
  <dependency>
    <groupId>com.cedarsoftware</groupId>
    <artifactId>json-io</artifactId>
-   <version>4.29.0</version>
+   <version>4.30.0</version>
  </dependency>
 ```
 ___
@@ -50,23 +50,23 @@ ___
 >- [ ] **Java Package**: com.cedarsoftware.io
 >- [ ] **Java**: JDK17+ (Class file 52 format, includes module-info.class - multi-release JAR)
 >- [ ] **API**
-   >  - Static methods on [JsonIo](https://www.javadoc.io/doc/com.cedarsoftware/json-io/latest/com/cedarsoftware/io/JsonIo.html): [toJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#toJson(java.lang.Object,com.cedarsoftware.io.WriteOptions)), [toObjects()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#toObjects(java.lang.String,com.cedarsoftware.io.ReadOptions,java.lang.Class)), [formatJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#formatJson(java.lang.String,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions)), [deepCopy()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#deepCopy(java.lang.Object,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions))
+   >  - Static methods on [JsonIo](https://www.javadoc.io/doc/com.cedarsoftware/json-io/latest/com/cedarsoftware/io/JsonIo.html): [toJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#toJson(java.lang.Object,com.cedarsoftware.io.WriteOptions)), [toObjects()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#toObjects(java.lang.String,com.cedarsoftware.io.ReadOptions,java.lang.Class)), [formatJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#formatJson(java.lang.String,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions)), [deepCopy()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#deepCopy(java.lang.Object,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions))
 >  - Use [ReadOptionsBuilder](/user-guide-readOptions.md) and [WriteOptionsBuilder](/user-guide-writeOptions.md) to configure `JsonIo`
->  - Use [JsonReader.ClassFactory](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonReader.ClassFactory.html) for difficult classes (hard to instantiate & fill)
->  - Use [JsonWriter.JsonClassWriter](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonWriter.JsonClassWriter.html) to customize the output JSON for a particular class
+>  - Use [JsonReader.ClassFactory](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonReader.ClassFactory.html) for difficult classes (hard to instantiate & fill)
+>  - Use [JsonWriter.JsonClassWriter](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonWriter.JsonClassWriter.html) to customize the output JSON for a particular class
 >- [ ] Updates will be 5.1.0, 5.2.0, ...
->### 4.29.0 (current)
->- [ ] **Version**: [4.29.0](https://www.javadoc.io/doc/com.cedarsoftware/json-io/4.29.0/index.html)
+>### 4.30.0 (current)
+>- [ ] **Version**: [4.30.0](https://www.javadoc.io/doc/com.cedarsoftware/json-io/4.30.0/index.html)
 >- [ ] **Bundling**: Both JPMS (Java Platform Module System) and OSGi (Open Service Gateway initiative)
 >- [ ] **Maintained**: Fully
 >- [ ] **Java Package**: com.cedarsoftware.io
 >- [ ] **Java**: JDK1.8+ (Class file 52 format, includes module-info.class - multi-release JAR)
 >- [ ] **API**
->  - Static methods on [JsonIo](https://www.javadoc.io/doc/com.cedarsoftware/json-io/latest/com/cedarsoftware/io/JsonIo.html): [toJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#toJson(java.lang.Object,com.cedarsoftware.io.WriteOptions)), [toObjects()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#toObjects(java.lang.String,com.cedarsoftware.io.ReadOptions,java.lang.Class)), [formatJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#formatJson(java.lang.String,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions)), [deepCopy()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonIo.html#deepCopy(java.lang.Object,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions))
+>  - Static methods on [JsonIo](https://www.javadoc.io/doc/com.cedarsoftware/json-io/latest/com/cedarsoftware/io/JsonIo.html): [toJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#toJson(java.lang.Object,com.cedarsoftware.io.WriteOptions)), [toObjects()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#toObjects(java.lang.String,com.cedarsoftware.io.ReadOptions,java.lang.Class)), [formatJson()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#formatJson(java.lang.String,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions)), [deepCopy()](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonIo.html#deepCopy(java.lang.Object,com.cedarsoftware.io.ReadOptions,com.cedarsoftware.io.WriteOptions))
 >  - Use [ReadOptionsBuilder](/user-guide-readOptions.md) and [WriteOptionsBuilder](/user-guide-writeOptions.md) to configure `JsonIo`
->  - Use [JsonReader.ClassFactory](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonReader.ClassFactory.html) for difficult classes (hard to instantiate & fill)
->  - Use [JsonWriter.JsonClassWriter](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.29.0/com/cedarsoftware/io/JsonWriter.JsonClassWriter.html) to customize the output JSON for a particular class
->- [ ] Updates will be 4.30.0, 4.31.0, ...
+>  - Use [JsonReader.ClassFactory](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonReader.ClassFactory.html) for difficult classes (hard to instantiate & fill)
+>  - Use [JsonWriter.JsonClassWriter](https://www.javadoc.io/static/com.cedarsoftware/json-io/4.30.0/com/cedarsoftware/io/JsonWriter.JsonClassWriter.html) to customize the output JSON for a particular class
+>- [ ] Updates will be 4.31.0, 4.32.0, ...
 >### 4.14.x (supported)
 >- [ ] **Version**: [4.14.3](https://www.javadoc.io/doc/com.cedarsoftware/json-io/4.14.3/index.html)
 >- [ ] **Bundling**: Both JPMS (Java Platform Module System) and OSGi (Open Service Gateway initiative)

changelog.md

@@ -1,6 +1,9 @@
 ### Revision History
+#### 4.30.0
+  * Root object type's like `Person[].class,` `String[].class,` can now be specified as the `rootType` and the return value will be `Person[],` `String[],` or a `ClassCastException` if the JSON data does not match the type.
+  * `JsonIo.formatJson()` three parameter version removed. Use the one (1) parameter API that takes the JSON to format. It runs much faster, as it no longer deserializes/serializes, but walks the JSON `String` directly.
 #### 4.29.0
-  * Consumed `java-util` `ClassUtilities.getClassLoader(),` which obtains the classLoader in a more robust way and works in OSGi and JPMS environment or non-framework environment
+  * Consumed `java-util's` `ClassUtilities.getClassLoader(),` which obtains the classLoader in a more robust way and works in OSGi and JPMS environment or non-framework environment
   * Removed `slf4j` and `logback-classic` from `test` dependencies
   * Merged in PR #297 by DaniellaHubble: Fix test that fails unexpectedly in `testEnumWithPrivateMembersAsField_withPrivatesOn()`
   * Updated [java-util](https://github.com/jdereg/java-util/blob/master/changelog.md) from `2.15.0` to `2.17.0.`

pom.xml

@@ -5,7 +5,7 @@
     <groupId>com.cedarsoftware</groupId>
     <artifactId>json-io</artifactId>
     <packaging>bundle</packaging>
-    <version>4.29.0</version>
+    <version>4.30.0</version>
     <description>Java JSON serialization</description>
     <url>https://github.com/jdereg/json-io</url>
 

src/main/java/com/cedarsoftware/io/JsonIo.java

@@ -11,6 +11,7 @@
 import java.util.Map;
 import java.util.Set;
 
+import com.cedarsoftware.io.prettyprint.JsonPrettyPrinter;
 import com.cedarsoftware.util.ClassUtilities;
 import com.cedarsoftware.util.Convention;
 import com.cedarsoftware.util.FastByteArrayInputStream;
@@ -35,7 +36,7 @@
  * streaming mode.  The JSON specification has great primitives which are universally useful in many languages. In
  * Java that is boolean, null, long [or BigInteger], and double [or BigDecimal], and String.<br/>
  * <br/>
- * When JsonObject is returned [option #3 or #4 above with readOptions.returnType(ReturnType.JSON_VALUES)], your root
+ * When JsonObject is returned [option #3 or #4 above with readOptions.returnAsNativeJsonObjects(), your root
  * value will represent one of:
  * <ul>JSON object {...}<br/>
  * JSON array [...]<br/>
@@ -224,33 +225,11 @@ public static <T> T toObjects(JsonObject jsonObject, ReadOptions readOptions, Cl
 
     /**
      * Format the passed in JSON into multi-line, indented format, commonly used in JSON online editors.
-     * @param readOptions ReadOptions to control the feature options. Can be null to take the defaults.
-     * @param writeOptions WriteOptions to control the feature options. Can be null to take the defaults.
      * @param json String JSON content.
      * @return String JSON formatted in human-readable, standard multi-line, indented format.
      */
-    public static String formatJson(String json, ReadOptions readOptions, WriteOptions writeOptions) {
-        if (writeOptions == null || !writeOptions.isPrettyPrint()) {
-            writeOptions = new WriteOptionsBuilder(writeOptions).prettyPrint(true).build();
-        }
-
-        if (readOptions == null) {
-            readOptions = ReadOptionsBuilder.getDefaultReadOptions();
-        } else if (!readOptions.isReturningJavaObjects()) {
-            readOptions = new ReadOptionsBuilder(readOptions).returnAsJavaObjects().build();
-        }
-
-        Object object = toObjects(json, readOptions, null);
-        return toJson(object, writeOptions);
-    }
-
-    /**
-     * Format the passed in JSON into multi-line, indented format, commonly used in JSON online editors.
-     * @param json String JSON content.
-     * @return String JSON formatted in human readable, standard multi-line, indented format.
-     */
     public static String formatJson(String json) {
-        return formatJson(json, null, null);
+        return JsonPrettyPrinter.prettyPrint(json);
     }
 
     /**
@@ -270,8 +249,6 @@ public static <T> T deepCopy(Object source, ReadOptions readOptions, WriteOption
         writeOptions = new WriteOptionsBuilder(writeOptions).showTypeInfoMinimal().shortMetaKeys(true).build();
         if (readOptions == null) {
             readOptions = ReadOptionsBuilder.getDefaultReadOptions();
-        } else {
-            readOptions = new ReadOptionsBuilder(readOptions).build();
         }
 
         String json = toJson(source, writeOptions);

src/main/java/com/cedarsoftware/io/prettyprint/JsonPrettyPrinter.java

@@ -0,0 +1,197 @@
+package com.cedarsoftware.io.prettyprint;
+
+/**
+ * @author John DeRegnaucourt ([email protected])
+ *         <br>
+ *         Copyright (c) Cedar Software LLC
+ *         <br><br>
+ *         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
+ *         <br><br>
+ *         <a href="http://www.apache.org/licenses/LICENSE-2.0">License</a>
+ *         <br><br>
+ *         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.
+ */
+public class JsonPrettyPrinter {
+    /**
+     * Takes a compact JSON string and returns a pretty-printed version with proper indentation.
+     *
+     * @param json The compact JSON string.
+     * @return A pretty-printed JSON string.
+     */
+    public static String prettyPrint(String json) {
+        if (json == null || json.isEmpty()) {
+            return json;
+        }
+
+        json = json.trim();
+
+        // Check if the root is a primitive (number, boolean, string, or null)
+        if (isPrimitive(json)) {
+            // For primitives, return the trimmed string
+            return json;
+        }
+
+        StringBuilder prettyJson = new StringBuilder();
+        int indentLevel = 0;
+        boolean inString = false;
+        boolean escape = false;
+
+        for (int i = 0; i < json.length(); i++) {
+            char currentChar = json.charAt(i);
+
+            if (escape) {
+                prettyJson.append(currentChar);
+                escape = false;
+                continue;
+            }
+
+            if (currentChar == '\\') {
+                escape = true;
+                prettyJson.append(currentChar);
+                continue;
+            }
+
+            if (currentChar == '\"') {
+                inString = !inString;
+                prettyJson.append(currentChar);
+                continue;
+            }
+
+            if (!inString) {
+                switch (currentChar) {
+                    case '{':
+                    case '[':
+                        prettyJson.append(currentChar);
+                        // Peek ahead to see if the next non-whitespace character is '}' or ']'
+                        if (!isNextCharClosing(json, i)) {
+                            prettyJson.append('\n');
+                            indentLevel++;
+                            appendIndentation(prettyJson, indentLevel);
+                        }
+                        break;
+                    case '}':
+                    case ']':
+                        // Newline before the closing brace/bracket if the previous non-whitespace character is not '{' or '['
+                        if (!isPrevCharOpening(json, i)) {
+                            prettyJson.append('\n');
+                            indentLevel--;
+                            appendIndentation(prettyJson, indentLevel);
+                        } else {
+                            // Decrease indentation level even if no newline is added
+                            indentLevel--;
+                        }
+                        prettyJson.append(currentChar);
+                        break;
+                    case ',':
+                        prettyJson.append(currentChar);
+                        // Peek ahead to see if the next non-whitespace character is not '}' or ']'
+                        if (!isNextCharClosing(json, i)) {
+                            prettyJson.append('\n');
+                            appendIndentation(prettyJson, indentLevel);
+                        }
+                        break;
+                    case ':':
+                        prettyJson.append(currentChar);
+                        // prettyJson.append(' '); // uncomment for space after the colon in "field": "value"
+                        break;
+                    default:
+                        if (!Character.isWhitespace(currentChar)) {
+                            prettyJson.append(currentChar);
+                        }
+                        break;
+                }
+            } else {
+                prettyJson.append(currentChar);
+            }
+        }
+
+        return prettyJson.toString();
+    }
+
+    /**
+     * Checks if the given JSON string represents a primitive value.
+     *
+     * @param json The JSON string.
+     * @return True if the JSON is a primitive, false otherwise.
+     */
+    private static boolean isPrimitive(String json) {
+        // Check for JSON null, boolean, number, or string
+        return isJsonNull(json) || isJsonBoolean(json) || isJsonNumber(json) || isJsonString(json);
+    }
+
+    private static boolean isJsonNull(String json) {
+        return "null".equals(json);
+    }
+
+    private static boolean isJsonBoolean(String json) {
+        return "true".equals(json) || "false".equals(json);
+    }
+
+    private static boolean isJsonNumber(String json) {
+        try {
+            Double.parseDouble(json);
+            return true;
+        } catch (NumberFormatException e) {
+            return false;
+        }
+    }
+
+    private static boolean isJsonString(String json) {
+        return json.startsWith("\"") && json.endsWith("\"");
+    }
+
+    /**
+     * Checks if the next non-whitespace character is a closing brace '}' or bracket ']'.
+     *
+     * @param json The JSON string.
+     * @param index The current index.
+     * @return True if the next non-whitespace character is '}' or ']', false otherwise.
+     */
+    private static boolean isNextCharClosing(String json, int index) {
+        for (int i = index + 1; i < json.length(); i++) {
+            char c = json.charAt(i);
+            if (Character.isWhitespace(c)) {
+                continue;
+            }
+            return c == '}' || c == ']';
+        }
+        return false;
+    }
+
+    /**
+     * Checks if the previous non-whitespace character is an opening brace '{' or bracket '['.
+     *
+     * @param json The JSON string.
+     * @param index The current index.
+     * @return True if the previous non-whitespace character is '{' or '[', false otherwise.
+     */
+    private static boolean isPrevCharOpening(String json, int index) {
+        for (int i = index - 1; i >= 0; i--) {
+            char c = json.charAt(i);
+            if (Character.isWhitespace(c)) {
+                continue;
+            }
+            return c == '{' || c == '[';
+        }
+        return false;
+    }
+
+    /**
+     * Appends indentation spaces to the StringBuilder based on the current indentation level.
+     *
+     * @param sb          The StringBuilder to append to.
+     * @param indentLevel The current indentation level.
+     */
+    private static void appendIndentation(StringBuilder sb, int indentLevel) {
+        final int INDENT_SIZE = 2; // Number of spaces for each indentation level
+        for (int i = 0; i < indentLevel * INDENT_SIZE; i++) {
+            sb.append(' ');
+        }
+    }
+}

src/test/java/com/cedarsoftware/io/TimeZoneTests.java

@@ -142,7 +142,7 @@ void testTimeZone_inCollection()
         String json = TestUtil.toJson(expected);
         TestUtil.printLine("json=" + json);
 
-       List<TimeZone> actual = (List<TimeZone>) TestUtil.toObjects(json, null);
+       List<TimeZone> actual = TestUtil.toObjects(json, null);
 
         // assert
         assertThat(actual).hasSize(2)
@@ -158,7 +158,7 @@ void testTimeZone_inMap_asValue()
         String json = TestUtil.toJson(expected);
         TestUtil.printLine("json=" + json);
 
-        Map actual = (Map<String, TimeZone>) TestUtil.toObjects(json, null);
+        Map actual = TestUtil.toObjects(json, null);
 
         assertThat(actual).hasSize(1)
                 .containsAllEntriesOf(expected);