数据库已经取出值，改怎么拼成一个xml形式的字符串
现在数据库已经取出a b c三个字段的所有值
大概是这样
a b c
a1 b1 3
a2 b2 1
a3 b3 2
a4 b4 1
a5 b5 3
a6 b6 1
a7 b7 2
a8 b8 2
a9 b9 1
a10 b10 3
xml：
<response>
<catolg name='1'>
<layer id='a2' counlom='b3'/>
<layer id='a6' counlom='b6'/>
<layer id='a9' counlom='b9'/>
</catolg>
<catolg name='2'>
...
...
</catolg>
<catolg name='3'>
...
...
</catolg>
</response>
拼成串也可以，使用jdom4j建树最好
while(rs.next){......}
------解决方案--------------------------------------------------------
- Java code
Document document = DocumentHelper.createDocument(); Element root = document.addElement("response"); while(rs.next()){ String id= rs.getString(0); //字段a String counlom= rs.getString(1); //字段b String catolg = rs.getString(2); //字段c Element catolgEl = ((Element)document.selectSingleNode("//response/catolg[@name='"+catolg+"']")); if(catolgEl==null){ catolgEl = root.addElement("catolg").addAttribute("name", catolg); } catolgEl.addElement("layer").addAttribute("id", id).addAttribute("counlom", counlom); } System.out.println(document.asXML());
------解决方案--------------------------------------------------------
这个不是例子，而是根据楼主要求写的。
楼主可以运行改下，只要把取数据那段换成你从数据库取就可以了。
用的就是dom4j
- Java code
import java.io.FileOutputStream;import java.io.OutputStreamWriter;import java.util.ArrayList;import java.util.List;import java.util.Map;import java.util.TreeMap;import org.dom4j.Document;import org.dom4j.DocumentHelper;import org.dom4j.Element;import org.dom4j.io.OutputFormat;import org.dom4j.io.XMLWriter;public class TestXML { class Data { public Data() { } String catolg; String id; String counlom; } public static void main(String[] args) { new TestXML().output("D:\\response.xml"); } public void output(String fileName) { String charset = "UTF-8"; Document doc = DocumentHelper.createDocument(); Element response = doc.addElement("response"); // 根元素 response doc.setRootElement(response); List<String> list = new ArrayList<String>(); list.add("a1 b1 3"); list.add("a2 b2 1"); list.add("a3 b3 2"); list.add("a4 b4 1"); list.add("a6 b6 1"); list.add("a7 b7 2"); list.add("a8 b8 2"); list.add("a9 b9 1"); list.add("a10 b10 3"); //排序 保证 catolg name="1" 然后 "2" "3" Map<String, ArrayList<Data>> sortedMap = new TreeMap<String, ArrayList<Data>>(); for (String line : list) { String arr[] = line.split(" "); Data d = new Data(); d.catolg = arr[2]; d.id = arr[0]; d.counlom = arr[1]; ArrayList<Data> l = sortedMap.get(d.catolg); if (l == null) { l = new ArrayList<Data>(); sortedMap.put(d.catolg, l); } l.add(d); } Map<String, Element> nameMap = new TreeMap<String, Element>(); for (ArrayList<Data> datas : sortedMap.values()) { for (Data d : datas) { String catolg = d.catolg; String id = d.id; String counlom = d.counlom; Element catolgElement = nameMap.get(catolg); if (catolgElement == null) { catolgElement = response.addElement("catolg"); catolgElement.addAttribute("name", catolg); nameMap.put(catolg, catolgElement); } Element layer = catolgElement.addElement("layer"); layer.addAttribute("id", id); layer.addAttribute("counlom", counlom); } } OutputFormat format = OutputFormat.createPrettyPrint(); // 设置XML文档输出格式 format.setEncoding(charset); // 设置XML文档的编码类型 format.setSuppressDeclaration(true); format.setIndent(true); // 设置是否缩进 format.setIndent("\t"); // 以空格方式实现缩进 format.setNewlines(true); // 设置是否换行 // format.setExpandEmptyElements(true); //设置空元素是头和尾都写 try { XMLWriter xmlWriter = new XMLWriter(new OutputStreamWriter( new FileOutputStream(fileName), charset), format); xmlWriter.write(response); xmlWriter.close(); } catch (Exception e) { e.printStackTrace(); } }}