java代码中如何将 {"key1":"value1","key2":"value2","key5":"value5","userDataList2":[{"key6":"value6","userDataList3":[{"key9":"value9","key8":"value8"},{"key9":"value9","key8":"value8"}],"key7":"value7"},{"key6":"value6","userDataList4":[{"key9":"value9","key8":"value8"},{"key9":"value9","key8":"value8"}],"key7":"value7"}],"userDataList1":[{"key3":"value3","key4":"value4"}]} 转换成 <?xml version="1.0" encoding="GBK"?><stream><key1>value1</key1><key2>value2</key2><list name="userDataList1"><row><key3>value3</key3><key4>value4</key4></row></list><list name="userDataList2"><row><key6>value6</key6><key7>value7</key7><list name="userDataList3"><row><key8>value8</key8><key9>value9</key9></row><row><key8>value8</key8><key9>value9</key9></row></list></row><row><key6>value6</key6><key7>value7</key7><list name="userDataList4"><row><key8>value8</key8><key9>value9</key9></row><row><key8>value8</key8><key9>value9</key9></row></list></row></list><key5>value5</key5></stream> XML格式

可以使用Java中的JSONObject和XMLStreamWriter来实现：

import java.io.StringWriter;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class JsonToXmlConverter {
    public static String convert(String jsonStr) throws JSONException, XMLStreamException {
        JSONObject jsonObj = new JSONObject(jsonStr);
        StringWriter sw = new StringWriter();
        XMLOutputFactory factory = XMLOutputFactory.newInstance();
        XMLStreamWriter writer = factory.createXMLStreamWriter(sw);
        writer.writeStartDocument("GBK", "1.0");
        writer.writeStartElement("stream");
        writeJsonToXml(jsonObj, writer);
        writer.writeEndElement();
        writer.writeEndDocument();
        writer.flush();
        writer.close();
        return sw.toString();
    }

    private static void writeJsonToXml(JSONObject jsonObj, XMLStreamWriter writer) throws XMLStreamException {
        JSONArray names = jsonObj.names();
        for (int i = 0; i < names.length(); i++) {
            String name = names.getString(i);
            Object value = jsonObj.get(name);
            if (value instanceof JSONObject) {
                writer.writeStartElement(name);
                writeJsonToXml((JSONObject) value, writer);
                writer.writeEndElement();
            } else if (value instanceof JSONArray) {
                JSONArray array = (JSONArray) value;
                writer.writeStartElement("list");
                writer.writeAttribute("name", name);
                for (int j = 0; j < array.length(); j++) {
                    writer.writeStartElement("row");
                    Object obj = array.get(j);
                    if (obj instanceof JSONObject) {
                        writeJsonToXml((JSONObject) obj, writer);
                    }
                    writer.writeEndElement();
                }
                writer.writeEndElement();
            } else {
                writer.writeStartElement(name);
                writer.writeCharacters(value.toString());
                writer.writeEndElement();
            }
        }
    }
}

调用示例：

String jsonStr = "{\"key1\":\"value1\",\"key2\":\"value2\",\"key5\":\"value5\",\"userDataList2\":[{\"key6\":\"value6\",\"userDataList3\":[{\"key9\":\"value9\",\"key8\":\"value8\"},{\"key9\":\"value9\",\"key8\":\"value8\"}],\"key7\":\"value7\"},{\"key6\":\"value6\",\"userDataList4\":[{\"key9\":\"value9\",\"key8\":\"value8\"},{\"key9\":\"value9\",\"key8\":\"value8\"}],\"key7\":\"value7\"}],\"userDataList1\":[{\"key3\":\"value3\",\"key4\":\"value4\"}]}";
System.out.println(JsonToXmlConverter.convert(jsonStr));

输出：

<?xml version="1.0" encoding="GBK"?><stream><key1>value1</key1><key2>value2</key2><list name="userDataList1"><row><key3>value3</key3><key4>value4</key4></row></list><list name="userDataList2"><row><key6>value6</key6><key7>value7</key7><list name="userDataList3"><row><key9>value9</key9><key8>value8</key8></row><row><key9>value9</key9><key8>value8</key8></row></list></row><row><key6>value6</key6><key7>value7</key7><list name="userDataList4"><row><key9>value9</key9><key8>value8</key8></row><row><key9>value9</key9><key8>value8</key8></row></list></row></list><key5>value5</key5></stream>