Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Databind Source Code files are provided in the source packge (jackson-databind-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Databind Source Code below:

⏎ com/fasterxml/jackson/databind/type/TypeParser.java

package com.fasterxml.jackson.databind.type;

import java.util.*;

import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.util.ClassUtil;

/**
 * Simple recursive-descent parser for parsing canonical {@link JavaType}
 * representations and constructing type instances.
 */
public class TypeParser
    implements java.io.Serializable
{
    private static final long serialVersionUID = 1L;

    protected final TypeFactory _factory;
        
    public TypeParser(TypeFactory f) {
        _factory = f;
    }

    /**
     * @since 2.6.2
     */
    public TypeParser withFactory(TypeFactory f) {
        return (f == _factory) ? this : new TypeParser(f);
    }

    public JavaType parse(String canonical) throws IllegalArgumentException
    {
        MyTokenizer tokens = new MyTokenizer(canonical.trim());
        JavaType type = parseType(tokens);
        // must be end, now
        if (tokens.hasMoreTokens()) {
            throw _problem(tokens, "Unexpected tokens after complete type");
        }
        return type;
    }

    protected JavaType parseType(MyTokenizer tokens)
        throws IllegalArgumentException
    {
        if (!tokens.hasMoreTokens()) {
            throw _problem(tokens, "Unexpected end-of-string");
        }
        Class<?> base = findClass(tokens.nextToken(), tokens);

        // either end (ok, non generic type), or generics
        if (tokens.hasMoreTokens()) {
            String token = tokens.nextToken();
            if ("<".equals(token)) {
                List<JavaType> parameterTypes = parseTypes(tokens);
                TypeBindings b = TypeBindings.create(base, parameterTypes);
                return _factory._fromClass(null, base, b);
            }
            // can be comma that separates types, or closing '>'
            tokens.pushBack(token);
        }
        return _factory._fromClass(null, base, TypeBindings.emptyBindings());
    }

    protected List<JavaType> parseTypes(MyTokenizer tokens)
        throws IllegalArgumentException
    {
        ArrayList<JavaType> types = new ArrayList<JavaType>();
        while (tokens.hasMoreTokens()) {
            types.add(parseType(tokens));
            if (!tokens.hasMoreTokens()) break;
            String token = tokens.nextToken();
            if (">".equals(token)) return types;
            if (!",".equals(token)) {
                throw _problem(tokens, "Unexpected token '"+token+"', expected ',' or '>')");
            }
        }
        throw _problem(tokens, "Unexpected end-of-string");
    }

    protected Class<?> findClass(String className, MyTokenizer tokens)
    {
        try {
            return _factory.findClass(className);
        } catch (Exception e) {
            ClassUtil.throwIfRTE(e);
            throw _problem(tokens, "Cannot locate class '"+className+"', problem: "+e.getMessage());
        }
    }

    protected IllegalArgumentException _problem(MyTokenizer tokens, String msg)
    {
        return new IllegalArgumentException(String.format("Failed to parse type '%s' (remaining: '%s'): %s",
                tokens.getAllInput(), tokens.getRemainingInput(), msg));
    }

    final static class MyTokenizer extends StringTokenizer
    {
        protected final String _input;

        protected int _index;

        protected String _pushbackToken;

        public MyTokenizer(String str) {            
            super(str, "<,>", true);
            _input = str;
        }

        @Override
        public boolean hasMoreTokens() {
            return (_pushbackToken != null) || super.hasMoreTokens();
        }
        
        @Override
        public String nextToken() {
            String token;
            if (_pushbackToken != null) {
                token = _pushbackToken;
                _pushbackToken = null;
            } else {
                token = super.nextToken();
                _index += token.length();
                token = token.trim();
            }
            return token;
        }

        public void pushBack(String token) {
            _pushbackToken = token;
            // let's NOT change index for now, since token may have been trim()ed
        }

        public String getAllInput() { return _input; }
//        public String getUsedInput() { return _input.substring(0, _index); }
        public String getRemainingInput() { return _input.substring(_index); }
    }
}

⏎ com/fasterxml/jackson/databind/type/TypeParser.java

Or download all of them as a single archive file:

File name: jackson-databind-2.14.0-sources.jar
File size: 1187952 bytes
Release date: 2022-11-05
Download 

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