java中Properties对文件进行读写

 

       1.获取系统用户目录的一个文件

       2.创建文件，用Propertes类写入数据到文件

       3.用Properties类读取文件的数据

 

public class CreateGroup extends PropertyPlaceholderConfigurer
{   
    public CreateGroup ()
    {
        init();
    }
    
    private void init()
    {
        try {
            String path = System.getProperty("user.home")+
                    File.separator+"dms-group.ini";
            Properties p = new Properties ();
            File f = new File (path);
            if (!f.exists ()||f.isDirectory ())
            {
                if (!f.createNewFile ())
                {
                    System.setProperty ("groupNameLC", "groupNameLC");
                    return;
                }
                OutputStream fos = new FileOutputStream(f);
                String name = "groupName"+new Date ().getTime ()+"GP";
                p.setProperty ("groupNameLC", name);
                p.store (fos, "######");
                fos.close ();
            }
            InputStream in = new FileInputStream (f); 
            p.load(in); 
            String gname = p.getProperty("groupNameLC").trim(); 
            System.setProperty ("groupNameLC", gname);
            in.close ();
        } catch (Exception e) { 
            e.printStackTrace();
        } 
    }
}