Convert Java `toString()` output to JSON

java_tostring_to_json.py

import json
import sys 

def parse_json_value(value):
    try:
        json_value = json.loads(value)
        return json_value
    except json.JSONDecodeError:
        return value

def is_json(value):
    return (value.startswith('{') and value.endswith('}')) or (value.startswith('[') and value.endswith(']'))

def inside_structure(edge_char_count):
    return edge_char_count != 0

def split_into_pairs(java_string):
    pairs = []
    current_key = ""
    current_value = ""
    braces_count = 0
    brackets_count = 0
    inside_value = False
    
    for char in java_string:
        if char == '=' and not inside_structure(braces_count) and not inside_structure(brackets_count):
            current_key = current_key.strip()
            inside_value = True
        elif char == ',' and not inside_structure(braces_count) and not inside_structure(brackets_count):
            current_value = current_value.strip()
            if current_key:
                pairs.append((current_key, current_value))
                current_key = ""
                current_value = ""
            inside_value = False
        elif char == '{':
            braces_count += 1
        elif char == '}':
            braces_count -= 1
        elif char == '[':
            brackets_count += 1
        elif char == ']':
            brackets_count -= 1
        
        if inside_value:
            current_value += char if char != '=' else ''
        elif char != '=':
            current_key += char if char != ',' else ''
            
    if current_key:
        current_value = current_value.strip()
        pairs.append((current_key, current_value))
    
    return pairs

def java_to_json(java_string):
    pairs = split_into_pairs(java_string)
    
    # Create a dictionary to store key-value pairs
    data = {}
    
    for key, value in pairs:
        if is_json(value):
            json_value = parse_json_value(value)
            data[key] = json_value
        else:
            data[key] = value.strip()
    
    return json.dumps(data, indent=2)

if len(sys.argv) < 2:
    print("Usage: python java_tostring_to_json.py 'java_output'")
    sys.exit(1)

java_output = sys.argv[1]

# Convert and print as JSON
json_output = java_to_json(java_output)
print(json_output)

How to use

POJO-generated strings have a wrapper around the content of the class, with the class's name and brackets, in this format:

MyPojoClass[<class_content>]

To use the script you must remove this wrapper, and call the script like this (must add the quote marks):

python java_tostring_to_json.py '<class_content>'