JsonToXmlWithLists.java

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;

import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class JsonToXmlWithLists {
    static class Row {
        private final String caption;
        private final String value;

        @JsonCreator
        Row(@JsonProperty("caption") String caption, @JsonProperty("value") String value) {
            this.caption = caption;
            this.value = value;
        }

        public String getCaption() {
            return caption;
        }

        public String getValue() {
            return value;
        }
    }

    @JacksonXmlRootElement(localName = "Table")
    static class XmlWrapper {
        @JacksonXmlElementWrapper(useWrapping = false)
        private final List<Row> row;

        @JsonCreator
        XmlWrapper(@JsonProperty("Row") List<Row> row) {
            this.row = row;
        }

        @JsonProperty("Row")
        public List<Row> getRow() {
            return row;
        }
    }

    private static Row rowFromMap(Map<String, String> currentEntry) {
        return new Row(currentEntry.get("caption"), currentEntry.get("value"));
    }

    public static void main(String[] args) throws IOException {
        final String testJson =
                "{\n" +
                        "    \"purpose\": {\n" +
                        "        \"caption\": \"Purpose\",\n" +
                        "        \"value\": \"Buy a goat\"\n" +
                        "    },\n" +
                        "    \"goatValue\": {\n" +
                        "        \"caption\": \"Goat value\",\n" +
                        "        \"value\": \"4500000\"\n" +
                        "    },\n" +
                        "    \"loanAmount\": {\n" +
                        "        \"caption\": \"Loan amount\",\n" +
                        "        \"value\": \"5000000\"\n" +
                        "    },\n" +
                        "    \"childrenInfo\": [{\n" +
                        "        \"gender\": {\n" +
                        "            \"caption\": \"Gender\",\n" +
                        "            \"value\": \"Boy\"\n" +
                        "        },\n" +
                        "        \"provider\": {\n" +
                        "            \"caption\": \"Provider\",\n" +
                        "            \"value\": \"Yes\"\n" +
                        "        },\n" +
                        "        \"age\": {\n" +
                        "            \"caption\": \"Age\",\n" +
                        "            \"value\": \"5\"\n" +
                        "        }\n" +
                        "    },\n" +
                        "    {\n" +
                        "        \"gender\": {\n" +
                        "            \"caption\": \"Gender\",\n" +
                        "            \"value\": \"Girl\"\n" +
                        "        },\n" +
                        "        \"provider\": {\n" +
                        "            \"caption\": \"Provider\",\n" +
                        "            \"value\": \"No\"\n" +
                        "        },\n" +
                        "        \"age\": {\n" +
                        "            \"caption\": \"Age\",\n" +
                        "            \"value\": \"17\"\n" +
                        "        }\n" +
                        "    }]\n" +
                        "}";
        final ObjectMapper jsonMapper = new ObjectMapper();
        final Map<String, Object> input = jsonMapper.readValue(testJson, new TypeReference<Map<String, Object>>() {});
        final List<Row> output = new LinkedList<Row>();

        for (String key : input.keySet()) {
            final Class<?> currentValueClass = input.get(key).getClass();
            if (Map.class.isAssignableFrom(currentValueClass)) {
                final Map<String, String> currentEntry = (Map<String, String>) input.get(key);
                output.add(rowFromMap(currentEntry));
            } else if (List.class.isAssignableFrom(currentValueClass)) {
                final List<Map<String, Map<String, String>>> currentEntry = (List<Map<String, Map<String, String>>>) input.get(key);
                for (Map<String, Map<String, String>> currentSubEntryWrapper : currentEntry) {
                    for (Map<String, String> currentSubEntry : currentSubEntryWrapper.values()) {
                        output.add(rowFromMap(currentSubEntry));
                    }
                }
            } else {
                System.err.println("Unhandled type for entry: " + key);
            }
        }
        final XmlWrapper xmlWrapper = new XmlWrapper(output);

        final XmlMapper xmlMapper = new XmlMapper();
        final String outputXml = xmlMapper.writeValueAsString(xmlWrapper);
        System.out.println(outputXml);
    }
}