动态创建和修改Spring的bean配置文件

2024年4月15日 互联网

1、如果只是创建一个XML文件，那么只需要导入dom4j-1.6.1.jar就可以了，路径如下：

spring-framework-2.5.6\lib\dom4j\dom4j-1.6.1.jar

如果是需要读取或者修改，那么就需要导入这个库内的另外一个文件：

spring-framework-2.5.6\lib\dom4j\jaxen-1.1-beta-7.jar

<dependency>

<groupId>org.apache.directory.studio</groupId>

<artifactId>org.dom4j.dom4j</artifactId>

<version>1.6.1</version>

</dependency>

<dependency>

<groupId>jaxen</groupId>

<artifactId>jaxen</artifactId>

<version>1.1-beta-7</version>

</dependency>

// MyDom4j.java

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.util.List;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.DocumentHelper;

import org.dom4j.Element;

import org.dom4j.Node;

import org.dom4j.io.SAXReader;

import org.dom4j.io.XMLWriter;

public class MyDom4j {

/**

* 动态创建一个bean配置文件，包含HelloWorld这个bean，并添加初始值

* */

public void createXML(String xmlPath, String msg) throws IOException {

Document XmlDoc = DocumentHelper.createDocument();

XmlDoc.addDocType("beans", "-//SPRING//DTD BEAN//EN",

"http://www.springframework.org/dtd/spring-beans.dtd");

//首先创建beans根节点

Element beansEle = XmlDoc.addElement("beans");

//注意：dom4j是支持类似于jQuery一样的链式操作的

Element beanHelloWorld = beansEle.addElement("bean")

.addAttribute("id", "HelloWorld")

.addAttribute("class", "HelloWorld");

Element propertyHelloWorld = beanHelloWorld.addElement("property")

.addAttribute("name", "msg");

Element valueHelloWorld = propertyHelloWorld.addElement("value")

.addText(msg);

XMLWriter outXml = new XMLWriter(new FileWriter(new File(xmlPath)));

outXml.write(XmlDoc);

outXml.close();

}

/**

* 首先遍历一个bean配置文件里的所有bean，获取id和class的值， 然后修改HelloWorld这个bean的msg的值

* @throws IOException

* */

public void editXML(String xmlPath, String msg) throws DocumentException, IOException {

Document XmlDoc = new SAXReader().read(new File(xmlPath));

List xmlList = XmlDoc.selectNodes("/beans/bean");

System.out.println("\r\n遍历所有的bean获得id和class：");

for (Element element : xmlList) {

System.out.println("id:" + element.attributeValue("id")

+ " / class:" + element.attributeValue("class"));

}

System.out.println("\r\n动态修改HelloWorld这个bean的msg值：");

//用XPath来获取单一节点

Node valueHelloWorld = XmlDoc

.selectSingleNode("/beans/bean[@id='HelloWorld']/property[@name='msg']/value");

System.out.println("原始值为：" + valueHelloWorld.getText());

valueHelloWorld.setText(msg);

System.out.println("修改后的值为：" + valueHelloWorld.getText());

//修改完了以后记得保存，要不然你会纳闷为什么XML文件没变的，哈哈

XMLWriter outXml = new XMLWriter(new FileWriter(new File(xmlPath)));

outXml.write(XmlDoc);

outXml.close();

}

}

// HelloWorld.java

public class HelloWorld {

public String msg;

public String getMsg() {

return msg;

}

public void setMsg(String msg) {

this.msg = msg;

}

}

// HelloWorldTester.java

import java.io.IOException;

import org.dom4j.DocumentException;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.FileSystemXmlApplicationContext;

import com.iteye.bolide74.action.HelloWorld;

import com.iteye.bolide74.action.MyDom4j;

public class HelloWorldTester {

public static void main(String[] args) {

String xmlPath = "/WebContent/WEB-INF/conf/config_dom4j.xml";

MyDom4j myBeans = new MyDom4j();

try {

myBeans.createXML(System.getProperty("user.dir") + xmlPath,

"Hello,world!this is created by dom4j!");

} catch (IOException e) {

e.printStackTrace();

}

ApplicationContext ac = new FileSystemXmlApplicationContext(xmlPath);

HelloWorld helloWorld = (HelloWorld) ac.getBean("HelloWorld");

System.out.println(helloWorld.getMsg());

try {

myBeans.editXML(System.getProperty("user.dir") + xmlPath,

"Hello,world!this is edited by dom4j!");

} catch (DocumentException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

// 重新获取bean配置文件

ac = new FileSystemXmlApplicationContext(xmlPath);

helloWorld = (HelloWorld) ac.getBean("HelloWorld");

System.out.println("\r\n" + helloWorld.getMsg());

}

}

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