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

Jackson also allows you to parse or generate XML messages with the Jackson Dataformat XML Extension.

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

You can also browse Jackson Dataformat XML Source Code below:

⏎ com/fasterxml/jackson/dataformat/xml/util/StaxUtil.java

package com.fasterxml.jackson.dataformat.xml.util;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.xml.stream.*;

import com.fasterxml.jackson.core.Base64Variant;
import com.fasterxml.jackson.core.Base64Variants;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;

public class StaxUtil
{
    /**
     * Adapter method used when only IOExceptions are declared to be thrown, but
     * a {@link XMLStreamException} was caught.
     *<p>
     * Note: dummy type variable is used for convenience, to allow caller to claim
     * that this method returns result of any necessary type.
     *
     * @deprecated Since 2.9
     */
    @Deprecated
    public static <T> T throwXmlAsIOException(XMLStreamException e) throws IOException
    {
        Throwable t = _unwrap(e);
        throw new IOException(t);
    }

    /**
     * @since 2.9
     */
    public static <T> T throwAsParseException(XMLStreamException e,
            JsonParser p) throws IOException
    {
        Throwable t = _unwrap(e);
        throw new JsonParseException(p, _message(t, e), t);
    }

    /**
     * @since 2.9
     */
    public static <T> T throwAsGenerationException(XMLStreamException e,
            JsonGenerator g) throws IOException
    {
        Throwable t = _unwrap(e);
        throw new JsonGenerationException(_message(t, e), t, g);
    }

    private static Throwable _unwrap(Throwable t) {
        while (t.getCause() != null) {
            t = t.getCause();
        }
        if (t instanceof Error) throw (Error) t;
        if (t instanceof RuntimeException) throw (RuntimeException) t;
        return t;
    }

    private static String _message(Throwable t1, Throwable t2) {
        String msg = t1.getMessage();
        if (msg == null) {
            msg = t2.getMessage();
        }
        return msg;
    }

    /**
     * Since XML names can not contain all characters JSON names can, we may
     * need to replace characters. Let's start with trivial replacement of
     * ASCII characters that can not be included.
     */
    public static String sanitizeXmlTypeName(String name)
    {
        // [dataformat-xml#451]: with DEDUCTION, at least, won't have property name
        //   (but probably sensible to check for it anyway)
        if (name == null) {
            return null;
        }
        
        StringBuilder sb;
        int changes = 0;
        // First things first: remove array types' trailing[]...
        if (name.endsWith("[]")) {
            do {
                name = name.substring(0, name.length() - 2);
                ++changes;
            } while (name.endsWith("[]"));
            sb = new StringBuilder(name);
            // do trivial pluralization attempt
            if (name.endsWith("s")) {
                sb.append("es");
            } else {
                sb.append('s');
            }
        } else {
            sb = new StringBuilder(name);
        }
        for (int i = 0, len = name.length(); i < len; ++i) {
            char c = name.charAt(i);
            if (c > 127) continue;
            if (c >= 'a' && c <= 'z') continue;
            if (c >= 'A' && c <= 'Z') continue;
            if (c >= '0' && c <= '9') continue;
            if (c == '_' || c == '.' || c == '-') continue;
            // Ok, need to replace
            ++changes;
            if (c == '$') {
                sb.setCharAt(i, '.');
            } else {
                sb.setCharAt(i, '_');
            }
        }
        if (changes == 0) {
            return name;
        }
        return sb.toString();
    }

    /**
     * Helper method used to "convert" Jackson's {@link Base64Variant} into corresponding
     * Stax2 equivalent, to try to allow Jackson-style configuration for XML output as well.
     *
     * @param j64b Jackson base64 variant to find match for
     *
     * @return Stax2 Base64 variant that most closely resembles Jackson canonical Base64 variant
     *     passed in as argument
     *
     * @since 2.12
     */
    public static org.codehaus.stax2.typed.Base64Variant toStax2Base64Variant(Base64Variant j64b) {
        return Base64Mapper.instance.map(j64b);
    }

    /**
     * @since 2.14
     */
    public static XMLInputFactory defaultInputFactory(ClassLoader cl) {
        // 05-Jul-2021, tatu: as per [dataformat-xml#483], specify ClassLoader
        try {
            return XMLInputFactory.newFactory(XMLInputFactory.class.getName(), cl);
        } catch (FactoryConfigurationError e) {
            // 24-Oct-2022, tatu: as per [dataformat-xml#550] need extra care
            return XMLInputFactory.newFactory();
        }
    }

    /**
     * @since 2.14
     */
    public static XMLOutputFactory defaultOutputFactory(ClassLoader cl) {
        // 05-Jul-2021, tatu: as per [dataformat-xml#483], specify ClassLoader
        try {
            return XMLOutputFactory.newFactory(XMLOutputFactory.class.getName(), cl);
        } catch (FactoryConfigurationError e) {
            // 24-Oct-2022, tatu: as per [dataformat-xml#550] need extra care
            return XMLOutputFactory.newFactory();
        }
    }

    private static class Base64Mapper {
        public final static Base64Mapper instance = new Base64Mapper();

        private final Map<String, org.codehaus.stax2.typed.Base64Variant> j2stax2
            = new HashMap<>();
        {
            j2stax2.put(Base64Variants.MIME.getName(), org.codehaus.stax2.typed.Base64Variants.MIME);
            j2stax2.put(Base64Variants.MIME_NO_LINEFEEDS.getName(),
                    org.codehaus.stax2.typed.Base64Variants.MIME_NO_LINEFEEDS);
            j2stax2.put(Base64Variants.MODIFIED_FOR_URL.getName(),
                    org.codehaus.stax2.typed.Base64Variants.MODIFIED_FOR_URL);
            j2stax2.put(Base64Variants.PEM.getName(), org.codehaus.stax2.typed.Base64Variants.PEM);
        }

        private Base64Mapper() {
        }

        public org.codehaus.stax2.typed.Base64Variant map(Base64Variant j64b) {
            org.codehaus.stax2.typed.Base64Variant result = j2stax2.get(j64b.getName());
            if (result == null) {
                // 13-May-2020, tatu: in unexpected case of no match, default to what Stax2
                //    considers default, not Jackson: this for backwards compatibility with
                //    Jackson 2.11 and earlier
                result = org.codehaus.stax2.typed.Base64Variants.getDefaultVariant();
            }
            return result;
        }
    }
}

⏎ com/fasterxml/jackson/dataformat/xml/util/StaxUtil.java

Or download all of them as a single archive file:

File name: jackson-dataformat-xml-2.14.0-sources.jar
File size: 98015 bytes
Release date: 2022-11-05
Download 

⇒ Download Jackson Dataformat Binary Packages

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