如何在Java中按升序对xml代码进行排序

Question

以下是我的XML代码，我需要按升序显示“节点名称”。

XML：

<node label="Tree Data">
<node name="View" type="Page">
<node name="Organisational Structure" type="Page"/>
<node name="Experience" type="Page"/>
<node name="Expertise" type="Language">
<node name="Flex" type="Language"/>
<node name="Android" type="Language"/>
<node name="Java" type="Language"/>
</node>
<node name="Project" type="Project">
<node name="Sabre" type="Project"/>
<node name="Android Project" type="Project"/>
<node name="Media Framework" type="Project"/>
<node name="CCD" type="Project"/>
<node name="Redbus" type="Project"/>
<node name="India Today" type="Project"/>
<node name="Money Control" type="Project"/>
</node>
</node>
<node name="Reorganize" type="Action"/>
<node name="Add New Employee" type="Action">
<node name="Dir" type="Page"/>
<node name="P.M" type="Page"/>
<node name="S.E" type="Page"/>
<node name="JUN" type="Page"/>
<node name="EMP" type="Page"/>
</node>
<node name="Add Project Members" type="Action"/>
</node>

以下是我的Java代码：

JAVA代码：

import java.io.IOException;
        import java.io.StringWriter;
        import java.net.URL;
        import java.util.ArrayList;
        import java.util.Collections;
        import java.util.List;

        import javax.xml.parsers.DocumentBuilder;
        import javax.xml.parsers.DocumentBuilderFactory;
        import javax.xml.parsers.ParserConfigurationException;
        import javax.xml.transform.OutputKeys;
        import javax.xml.transform.Transformer;
        import javax.xml.transform.TransformerException;
        import javax.xml.transform.TransformerFactory;
        import javax.xml.transform.dom.DOMSource;
        import javax.xml.transform.stream.StreamResult;

        import org.w3c.dom.Document;
        import org.w3c.dom.Element;
        import org.w3c.dom.NamedNodeMap;
        import org.w3c.dom.Node;
        import org.w3c.dom.NodeList;
        import org.xml.sax.InputSource;
        import org.xml.sax.SAXException;

        import android.os.Bundle;
        import android.app.Activity;
        import android.view.Menu;

        public class MainActivity extends Activity {

            Document dom;

            public MainActivity() {
                MainActivity();

                ArrayList<Element> listGroup = getGroups();

            }




            private ArrayList getGroups() {
                try {
                    Element documentElement = (Element) dom.getDocumentElement();
                    System.out.println("root element is :"+documentElement.getNodeName());
                    NodeList childNodes = documentElement.getElementsByTagName("node");

                    for (int i = 0; i < childNodes.getLength(); i++) {

                        if (childNodes.item(i).getNodeType() == Node.ELEMENT_NODE) {
                            Element element = (Element) childNodes.item(i);
                            if(((Element) childNodes.item(i)).hasAttribute("name")) {
                            String name = element.getAttribute("name");
                            String type = element.getAttribute("type");
                            System.out.println("name : " + name);
                            System.out.println("type : " + type);
                        }}
                    }
                } catch (Exception e) {
                }
                return null;

            }

            private void MainActivity() {
                DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();


                try {
                    String sURL = "huhhadjdhjshdjks.com";
                    URL url = new URL(sURL);
                    DocumentBuilder db = dbf.newDocumentBuilder();

                    dom = db.parse(new InputSource(url.openStream()));

                } catch (ParserConfigurationException pce) {
                    pce.printStackTrace();
                } catch (SAXException se) {
                    se.printStackTrace();
                } catch (IOException ioe) {
                    ioe.printStackTrace();
                }
            }
        }

我得到以下输出：

logcat：

01-31 17:45:59.330: I/System.out(1871): root element is :node
01-31 17:45:59.340: I/System.out(1871): name : View
01-31 17:45:59.360: I/System.out(1871): type : Page
01-31 17:45:59.380: I/System.out(1871): name : Organisational Structure
01-31 17:45:59.380: I/System.out(1871): type : Page
01-31 17:45:59.400: I/System.out(1871): name : Experience
01-31 17:45:59.400: I/System.out(1871): type : Page
01-31 17:45:59.400: I/System.out(1871): name : Expertise
01-31 17:45:59.400: I/System.out(1871): type : Language
01-31 17:45:59.400: I/System.out(1871): name : Flex
01-31 17:45:59.410: I/System.out(1871): type : Language
01-31 17:45:59.410: I/System.out(1871): name : Android
01-31 17:45:59.420: I/System.out(1871): type : Language
01-31 17:45:59.420: I/System.out(1871): name : Java
01-31 17:45:59.430: I/System.out(1871): type : Language
01-31 17:45:59.430: I/System.out(1871): name : Project
01-31 17:45:59.430: I/System.out(1871): type : Project
01-31 17:45:59.440: I/System.out(1871): name : Sabre
01-31 17:45:59.440: I/System.out(1871): type : Project
01-31 17:45:59.440: I/System.out(1871): name : Android Project
01-31 17:45:59.450: I/System.out(1871): type : Project
01-31 17:45:59.450: I/System.out(1871): name : Media Framework
01-31 17:45:59.460: I/System.out(1871): type : Project
01-31 17:45:59.460: I/System.out(1871): name : CCD
01-31 17:45:59.460: I/System.out(1871): type : Project
01-31 17:45:59.460: I/System.out(1871): name : Redbus
01-31 17:45:59.460: I/System.out(1871): type : Project
01-31 17:45:59.460: I/System.out(1871): name : India Today
01-31 17:45:59.480: I/System.out(1871): type : Project
01-31 17:45:59.480: I/System.out(1871): name : Money Control
01-31 17:45:59.489: I/System.out(1871): type : Project
01-31 17:45:59.489: I/System.out(1871): name : Reorganize
01-31 17:45:59.500: I/System.out(1871): type : Action
01-31 17:45:59.500: I/System.out(1871): name : Add New Employee
01-31 17:45:59.500: I/System.out(1871): type : Action
01-31 17:45:59.500: I/System.out(1871): name : Dir
01-31 17:45:59.500: I/System.out(1871): type : Page
01-31 17:45:59.510: I/System.out(1871): name : P.M
01-31 17:45:59.510: I/System.out(1871): type : Page
01-31 17:45:59.510: I/System.out(1871): name : S.E
01-31 17:45:59.530: I/System.out(1871): type : Page
01-31 17:45:59.530: I/System.out(1871): name : JUN
01-31 17:45:59.530: I/System.out(1871): type : Page
01-31 17:45:59.530: I/System.out(1871): name : EMP
01-31 17:45:59.530: I/System.out(1871): type : Page
01-31 17:45:59.530: I/System.out(1871): name : Add Project Members
01-31 17:45:59.530: I/System.out(1871): type : Action

我需要所有名称按升序排列。 有什么帮助吗？

Answer 1

创建一个变量items来存储name和type ：

Map<String, String> items = new HashMap<>();
items.put(name, type);

排序names ：

List<String> keys = new ArrayList(items.keySet());
Collections.sort(keys);

然后输出它们：

for (String key : keys) {
    System.out.println("name : " + key);
    System.out.println("type : " + items.get(key));        
}

Answer 2

您将其加载到数组中并对其进行排序。 XML的读取方式有两种（通常）。

1.）您要构建树（DOM），因此它的顺序不按升序排列。 您可以进行树遍历并获得结果排序。

2.）SAX就像解析标签的解析一样，您需要进行一些处理，但是读取文档所占用的内存却非常少。

Answer 3

这是一个递归元素排序器。 不幸的是，它仅适用于XOM Elements。

private void sortElement(Element e) {
  // Remove them all.
  Nodes nodes = e.removeChildren();

  // Sort them.
  Map<String, List<Element>> sorted = new TreeMap<String, List<Element>>();
  for (int i = 0; i < nodes.size(); i++) {
    Node n = nodes.get(i);
    if (n instanceof Element) {
      Element it = (Element) n;
      // Get it sorted.
      sortElement(it);
      // Key it by name and then its xml.
      String key = it.getLocalName() + "!" + it.toXML();
      // Add it.
      List<Element> in = sorted.get(key);
      if (in == null) {
        in = new ArrayList<Element>();
      }
      in.add(it);
      sorted.put(key, in);
    }
  }
  // Add them all back in.
  for (Entry<String, List<Element>> entry : sorted.entrySet()) {
    for (Element a : entry.getValue()) {
      e.appendChild(a);
    }
  }
}

Answer 4

在这里，您可以找到静态方法sortNodes以按任何属性对NodeList进行排序

和简单的XML示例：

*** Sort by id ***
1 : 100.00
2 : 5.10
3 : 29.99
*** Sort by price ***
2 : 5.10
3 : 29.99
1 : 100.00

希望能帮助到你。