WebService在传递数据的时候只能传递字符串,当我们返回一些简单的字符串时我们可以直接返回,但是当我们想返回比如List,Map等复杂类型的数据时拼接字符串就是个很麻烦的工作,这时我们就用到了dom4j这个工具。
当我们从数据库中查询出很多个对象类型时,我们一般都存放在List中。像这种数据就很难用拼接字符串的形式进行传递。我的解决办法就是利用dom4j把它写成一个xml格式的字符串,然后在客户端再利用dom4j解释。
假如我们从数据库中查询的是一个Student对象,该对象有name和agel两个属性,我们将大量的Student对象储存在List中。下面我们想利用dom4j把List数据变成如下格式的xml文件类型的字符串:
[xhtml:showcolumns:firstline[1]] view plain copy print ? ·········10········20········30········40········50········60········70········80········90········100·······110·······120·······130·······140·······150
- <?xml version="1.0" encoding="UTF-8"?>
- <root>
- <student>
- <name>张三</name>
- <age>26</age>
- </student>
- <student>
- <name>赵四</name>
- <age>34</age>
- </student>
- </root>
<?xml version="1.0" encoding="UTF-8"?>
<root>
<student>
<name>张三</name>
<age>26</age>
</student>
<student>
<name>赵四</name>
<age>34</age>
</student>
</root>
webservice端java代码如下:
[java:showcolumns:firstline[1]] view plain copy print ? ·········10········20········30········40········50········60········70········80········90········100·······110·······120·······130·······140·······150
- import java.util.List;
- import org.dom4j.Document;
- import org.dom4j.DocumentHelper;
- import org.dom4j.Element;
- import org.dom4j.io.OutputFormat;
- import vo.UnitPO;
- import DAO.unitDao;
- public class Service02 {
- public String method(){
- Document document = DocumentHelper.createDocument();
- Element root = document.addElement("root");
- Element stuElement = null;
- Element nameElement = null;
- Element ageElement = null;
- //第一个student节点
- stuElement = root.addElement("student");
- //添加两个子节点
- nameElement = stuElement.addElement("name");
- ageElement = stuElement.addElement("age");
- //向两个子节点中添加文本内容
- nameElement.addText("张三");
- ageElement.addText("26");
- //同理第二个student节点
- stuElement = root.addElement("student");
- nameElement = stuElement.addElement("name");
- ageElement = stuElement.addElement("age");
- nameElement.addText("赵四");
- ageElement.addText("34");
- try {
- OutputFormat format = OutputFormat.createPrettyPrint();
- // 设置XML文件的编码格式
- format.setEncoding("UTF-8");
- return document.asXML();
- } catch (Exception e) {
- System.out.println(e.getMessage());
- return "error";
- }
- }
- }
import java.util.List;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import vo.UnitPO;
import DAO.unitDao;
public class Service02 {
public String method(){
Document document = DocumentHelper.createDocument();
Element root = document.addElement("root");
Element stuElement = null;
Element nameElement = null;
Element ageElement = null;
//第一个student节点
stuElement = root.addElement("student");
//添加两个子节点
nameElement = stuElement.addElement("name");
ageElement = stuElement.addElement("age");
//向两个子节点中添加文本内容
nameElement.addText("张三");
ageElement.addText("26");
//同理第二个student节点
stuElement = root.addElement("student");
nameElement = stuElement.addElement("name");
ageElement = stuElement.addElement("age");
nameElement.addText("赵四");
ageElement.addText("34");
try {
OutputFormat format = OutputFormat.createPrettyPrint();
// 设置XML文件的编码格式
format.setEncoding("UTF-8");
return document.asXML();
} catch (Exception e) {
System.out.println(e.getMessage());
return "error";
}
}
}
这样就将我们想传送的复杂数据变成了xml格式是字符串,下面在客户端就可以解释出我们想要的数据了。
client端java代码如下:
[java:showcolumns:firstline[1]] view plain copy print ? ·········10········20········30········40········50········60········70········80········90········100·······110·······120·······130·······140·······150
- import java.io.StringReader;
- import java.util.List;
- import org.dom4j.Document;
- import org.dom4j.Element;
- import org.dom4j.io.SAXReader;
- import webservice.Service02Proxy;
- public class Test {
- public static void main(String[] args) {
- try{
- //创建代理类
- Service02Proxy proxy = new Service02Proxy();
- //接受传过来的XML字符串
- String str = proxy.method();
- //解释该字符串
- StringReader read = new StringReader(str);
- SAXReader reader = new SAXReader();
- Document doc = reader.read(read);
- Element root = doc.getRootElement();
- //该节点由多个student构成,所以返回值是List类型
- List list = root.elements("student");
- for(int i = 0;i < list.size();i++){
- Element student = (Element)list.get(i);
- Element name = student.element("name");
- Element age = student.element("age");
- //打印得到的数据
- System.out.println(name.getTextTrim()+":"+age.getTextTrim());
- }
- }catch(Exception e){
- e.printStackTrace();
- }
- }
- }
import java.io.StringReader;
import java.util.List;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import webservice.Service02Proxy;
public class Test {
public static void main(String[] args) {
try{
//创建代理类
Service02Proxy proxy = new Service02Proxy();
//接受传过来的XML字符串
String str = proxy.method();
//解释该字符串
StringReader read = new StringReader(str);
SAXReader reader = new SAXReader();
Document doc = reader.read(read);
Element root = doc.getRootElement();
//该节点由多个student构成,所以返回值是List类型
List list = root.elements("student");
for(int i = 0;i < list.size();i++){
Element student = (Element)list.get(i);
Element name = student.element("name");
Element age = student.element("age");
//打印得到的数据
System.out.println(name.getTextTrim()+":"+age.getTextTrim());
}
}catch(Exception e){
e.printStackTrace();
}
}
}
控制台输出为:
张三:26
赵四:34
每种编程语言可能接受时用的类型不同,但方法大同小异。代码如有问题,欢迎给予评价。