Package com.tnsai.parser

Class JsonOutputParser<T>

java.lang.Object

com.tnsai.parser.JsonOutputParser<T>

Type Parameters:

T - the target type

All Implemented Interfaces:

OutputParser<T>

public class JsonOutputParser<T>
extends Object
implements OutputParser<T>

JSON-based output parser that converts LLM JSON output into Java objects.

Features:

• Automatic JSON extraction from markdown code blocks
• Support for Java Records and POJOs
• Field validation with annotations
• Detailed error messages for LLM correction

Usage

 // For a record
 record Person(String name, int age) {}
 JsonOutputParser<Person> parser = JsonOutputParser.forType(Person.class);

 // Parse LLM output (handles JSON in markdown blocks too)
 ParseResult<Person> result = parser.parse("""
     Here's the person data:
     ```json
     {"name": "John", "age": 30}
     ```
     """);

 Person person = result.get();
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	JsonOutputParser.Builder<T>	Builder for JsonOutputParser.

Method Summary

Modifier and Type	Method	Description
static <T> JsonOutputParser.Builder<T>	builder(Class<T> targetType)	Creates a builder for customizing the parser.
static <T> JsonOutputParser<T>	forType(Class<T> targetType)	Creates a parser for the given type with default settings.
String	getFormatInstruction()	Returns a format instruction string to include in the LLM prompt.
String	getSchemaDescription()	Returns a schema description of the expected output format.
Class<T>	getTargetType()	Returns the target class this parser produces.
ParseResult<T>	parse(String output)	Parses the raw LLM output into the target type.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.tnsai.parser.OutputParser

getErrorCorrectionPrompt, parseOptional, parseOrThrow

Method Details

forType

public static <T> JsonOutputParser<T> forType(Class<T> targetType)

Creates a parser for the given type with default settings.

Type Parameters:

T - the type

Parameters:

targetType - the target class

Returns:

new parser

builder

public static <T> JsonOutputParser.Builder<T> builder(Class<T> targetType)

Creates a builder for customizing the parser.

Type Parameters:

T - the type

Parameters:

targetType - the target class

Returns:

new builder

parse

public ParseResult<T> parse(String output)

Description copied from interface: OutputParser

Parses the raw LLM output into the target type.

Specified by:

parse in interface OutputParser<T>

Parameters:

output - the raw string output from the LLM

Returns:

parse result containing either the parsed object or error details

getTargetType

public Class<T> getTargetType()

Description copied from interface: OutputParser

Returns the target class this parser produces.

Specified by:

getTargetType in interface OutputParser<T>

Returns:

the target class

getFormatInstruction

public String getFormatInstruction()

Description copied from interface: OutputParser

Returns a format instruction string to include in the LLM prompt.

This helps guide the LLM to produce output in the expected format.

Specified by:

getFormatInstruction in interface OutputParser<T>

Returns:

format instruction for the prompt

getSchemaDescription

public String getSchemaDescription()

Description copied from interface: OutputParser

Returns a schema description of the expected output format.

Specified by:

getSchemaDescription in interface OutputParser<T>

Returns:

schema description (e.g., JSON Schema, example)