package Zy; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.Properties; import java.util.Set; /*2.用代码实现以下需求: (1)已知配置文件config.properties中有三个键值对 name=zhangsan score=80 address=beijing (2)使用IO字节流对象和Properties类结合使用,将配置文件中的score键的值修改为100*/ public class Zy02 { public static void main(String[] args) throws IOException { Properties pro=new Properties(); FileInputStream fis=new FileInputStream("d:\java\config.properties"); pro.load(fis); Set<String> str=pro.stringPropertyNames(); for(String s:str){ if(s.equals("score")){ pro.setProperty(s, "100"); }else{ pro.setProperty(s, pro.getProperty(s)); } System.out.println(s+"..."+pro.getProperty(s)); FileOutputStream fos=new FileOutputStream("d:\java\config.properties"); pro.store(fos, "message"); fos.close(); } } }