简析Properties对*.xml文件的读取与写入

偏执的太偏执、 2022-08-23 13:56 226阅读 0赞

test.xml文件

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
    <properties>
    	<entry key="key1">value值1</entry>
    	<entry key="key2">value2</entry>
    </properties>

java解析代码：

import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.PrintStream;
    import java.util.Properties;
    
    public class xmlTest {
    
    	public static void main(String[] args) {
    		try {
    //			读取*.xml文件
    			FileInputStream stream = new FileInputStream("conf/test.xml");
    			Properties properties = new Properties();
    			properties.loadFromXML(stream);
    //			1、读取整个*.xml文件内容
    			properties.list(System.out);
    //			2、按键值对的方式读取
    			String name = properties.getProperty("key1");
    			System.out.println(name);//value值1
    //			3、循环遍历读取
    			for(Object obj:properties.keySet()){
    				String key = (String)obj;
    				String value = properties.getProperty(key);
    				System.out.println("key:"+key+",value:"+value);
    			}
    			
    //			写入并保存*.xml文件
    			properties.setProperty("key2","modifyValue2");//改变配置文件中的值
    			properties.put("key3", "value值3");//增加键值对
    			PrintStream print = new PrintStream(new File("conf/testNew2.xml"));//创建新文件
    //			通过storeToXML方法将xml内容写入.xml文件
    			properties.storeToXML(print,"test");//配置文件中增加<comment>test</comment>
    		} catch (FileNotFoundException e) {
    			e.printStackTrace();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    }

执行结果：

新创建的testNew2.xml内容

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
    <properties>
    <comment>test</comment>
    <entry key="key3">value值3</entry>
    <entry key="key2">modifyValue2</entry>
    <entry key="key1">value值1</entry>
    </properties>