tessl/maven-com-alibaba-fastjson2--fastjson2

FASTJSON 2 is a high-performance and easy-to-use Java JSON processing library with extreme performance that far exceeds other popular JSON libraries.

—

Pending

Overview

Eval results

Files

Data Structures

Name: tessl/maven-com-alibaba-fastjson2--fastjson2
Author: tessl

Enhanced JSONObject and JSONArray classes providing type-safe access methods and advanced functionality beyond standard Map/List interfaces. These classes offer optimized JSON-specific operations and seamless conversion capabilities.

Capabilities

JSONObject

Enhanced LinkedHashMap implementation with type-safe getters, JSONPath support, and conversion utilities.

/**
 * JSON object implementation extending LinkedHashMap
 */
public class JSONObject extends LinkedHashMap<String, Object> implements InvocationHandler {
    
    /**
     * Get string value by key
     * @param key Property key
     * @return String value or null
     */
    public String getString(String key);
    
    /**
     * Get integer value by key
     * @param key Property key
     * @return Integer value or null
     */
    public Integer getInteger(String key);
    
    /**
     * Get long value by key
     * @param key Property key
     * @return Long value or null
     */
    public Long getLong(String key);
    
    /**
     * Get double value by key
     * @param key Property key
     * @return Double value or null
     */
    public Double getDouble(String key);
    
    /**
     * Get primitive double value by key
     * @param key Property key
     * @return double value or 0.0 if null
     */
    public double getDoubleValue(String key);
    
    /**
     * Get primitive long value by key  
     * @param key Property key
     * @return long value or 0L if null
     */
    public long getLongValue(String key);
    
    /**
     * Get primitive int value by key
     * @param key Property key
     * @return int value or 0 if null
     */
    public int getIntValue(String key);
    
    /**
     * Get primitive boolean value by key
     * @param key Property key
     * @return boolean value or false if null
     */
    public boolean getBooleanValue(String key);
    
    /**
     * Get boolean value by key
     * @param key Property key
     * @return Boolean value or null
     */
    public Boolean getBoolean(String key);
    
    /**
     * Get nested JSONObject by key
     * @param key Property key
     * @return JSONObject or null
     */
    public JSONObject getJSONObject(String key);
    
    /**
     * Get JSONArray by key
     * @param key Property key
     * @return JSONArray or null
     */
    public JSONArray getJSONArray(String key);
    
    /**
     * Get List value by key
     * @param key Property key
     * @return List or null
     */
    public List getList(String key);
    
    /**
     * Access nested values using JSONPath expression
     * @param jsonPath Path expression (e.g., "$.user.name")
     * @return Value at specified path
     */
    public Object getByPath(String jsonPath);
    
    /**
     * Convert to specific Java class
     * @param clazz Target class type
     * @return Instance of specified class
     */
    public <T> T to(Class<T> clazz);
    
    /**
     * Convert to Java object (alias for to())
     * @param clazz Target class type
     * @return Instance of specified class
     */
    public <T> T toJavaObject(Class<T> clazz);
    
    /**
     * Iterate over array objects in this JSONObject
     */
    public void forEachArrayObject();
}

JSONArray

Enhanced ArrayList implementation with type-safe getters and conversion utilities for JSON arrays.

/**
 * JSON array implementation extending ArrayList
 */
public class JSONArray extends ArrayList<Object> {
    
    /**
     * Get string value by index
     * @param index Array index
     * @return String value or null
     */
    public String getString(int index);
    
    /**
     * Get integer value by index
     * @param index Array index
     * @return Integer value or null
     */
    public Integer getInteger(int index);
    
    /**
     * Get long value by index
     * @param index Array index
     * @return Long value or null
     */
    public Long getLong(int index);
    
    /**
     * Get double value by index
     * @param index Array index
     * @return Double value or null
     */
    public Double getDouble(int index);
    
    /**
     * Get primitive double value by index
     * @param index Array index
     * @return double value or 0.0 if null
     */
    public double getDoubleValue(int index);
    
    /**
     * Get primitive long value by index
     * @param index Array index
     * @return long value or 0L if null
     */
    public long getLongValue(int index);
    
    /**
     * Get primitive int value by index
     * @param index Array index
     * @return int value or 0 if null
     */
    public int getIntValue(int index);
    
    /**
     * Get primitive boolean value by index
     * @param index Array index
     * @return boolean value or false if null
     */
    public boolean getBooleanValue(int index);
    
    /**
     * Get boolean value by index
     * @param index Array index
     * @return Boolean value or null
     */
    public Boolean getBoolean(int index);
    
    /**
     * Get nested JSONObject by index
     * @param index Array index
     * @return JSONObject or null
     */
    public JSONObject getJSONObject(int index);
    
    /**
     * Get nested JSONArray by index
     * @param index Array index
     * @return JSONArray or null
     */
    public JSONArray getJSONArray(int index);
    
    /**
     * Convert to specific Java class
     * @param clazz Target class type
     * @return Instance of specified class
     */
    public <T> T to(Class<T> clazz);
    
    /**
     * Convert to Java array
     * @return Object array
     */
    public Object[] toArray();
    
    /**
     * Convert to typed Java List
     * @param clazz Element class type
     * @return List of specified element type
     */
    public <T> List<T> toJavaList(Class<T> clazz);
    
    /**
     * Enhanced set method with negative indexing and auto-expansion
     * @param index Array index (supports negative indexing)
     * @param value Value to set
     * @return Previous value at index
     */
    public Object set(int index, Object value);
}

Usage Examples:

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.JSONArray;

// JSONObject usage
String json = "{\"name\":\"John\",\"age\":30,\"active\":true,\"scores\":[95,87,92]}";
JSONObject obj = JSON.parseObject(json);

// Type-safe getters
String name = obj.getString("name");        // "John"
Integer age = obj.getInteger("age");        // 30
Boolean active = obj.getBoolean("active"); // true
JSONArray scores = obj.getJSONArray("scores");

// JSONPath access
String nestedJson = "{\"user\":{\"profile\":{\"name\":\"John\"}}}";
JSONObject nested = JSON.parseObject(nestedJson);
String userName = (String) nested.getByPath("$.user.profile.name"); // "John"

// Convert to custom object
User user = obj.to(User.class);

// JSONArray usage
String arrayJson = "[{\"name\":\"John\",\"age\":30},{\"name\":\"Jane\",\"age\":25}]";
JSONArray array = JSON.parseArray(arrayJson);

// Access by index
JSONObject firstUser = array.getJSONObject(0);
String firstName = firstUser.getString("name"); // "John"

// Convert to typed list
List<User> users = array.toJavaList(User.class);

// Enhanced set with negative indexing
JSONArray numbers = JSON.parseArray("[1,2,3,4,5]");
numbers.set(-1, 10); // Sets last element to 10: [1,2,3,4,10]

// Auto-expansion
JSONArray expandable = new JSONArray();
expandable.set(5, "value"); // Automatically expands to index 5

Advanced JSONObject Features

// Complex nested structure access
String complexJson = """
{
  "users": [
    {"name": "John", "addresses": [{"city": "NYC"}, {"city": "LA"}]},
    {"name": "Jane", "addresses": [{"city": "SF"}]}
  ]
}
""";

JSONObject complex = JSON.parseObject(complexJson);

// Access nested arrays and objects
JSONArray users = complex.getJSONArray("users");
JSONObject firstUser = users.getJSONObject(0);
JSONArray addresses = firstUser.getJSONArray("addresses");
String firstCity = addresses.getJSONObject(0).getString("city"); // "NYC"

// Using JSONPath for complex access
String firstUserCity = (String) complex.getByPath("$.users[0].addresses[0].city"); // "NYC"

// Convert specific nested objects
User firstUserObj = firstUser.to(User.class);
List<Address> userAddresses = addresses.toJavaList(Address.class);

Type Conversion Examples

// JSONObject conversions
JSONObject obj = JSON.parseObject("{\"id\":1,\"name\":\"Product\",\"price\":99.99}");

// Safe type conversion with null handling
Integer id = obj.getInteger("id");           // 1
String name = obj.getString("name");         // "Product"  
Double price = obj.getDouble("price");       // 99.99
Integer missing = obj.getInteger("missing"); // null

// Convert entire object
Product product = obj.to(Product.class);

// JSONArray conversions
JSONArray numbers = JSON.parseArray("[1,2,3,4,5]");
JSONArray mixed = JSON.parseArray("[\"hello\",42,true,null]");

String first = mixed.getString(0);    // "hello"
Integer second = mixed.getInteger(1); // 42
Boolean third = mixed.getBoolean(2);  // true
Object fourth = mixed.get(3);         // null

// Convert to standard Java collections
List<Integer> numberList = numbers.toJavaList(Integer.class);
Object[] mixedArray = mixed.toArray();

Install with Tessl CLI

npx tessl i tessl/maven-com-alibaba-fastjson2--fastjson2

docs