读取properties配置文件

待我称王封你为后i 2022-07-16 07:00 351阅读 0赞

### 读取properties配置文件 ###

#### PropertiesUtil.java、template.properties、Main.java处于同一目录 ####

#### 1、PropertiesUtil.javatemplate.properties类 ####

import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.util.Properties;
    
    /** * Created by jaer on 2016/10/10. * 读取配置文件类 */
    public class PropertiesUtil { 
        private static Properties prop;
        private static PropertiesUtil instance = new PropertiesUtil();
    
        /** 文件名称 */
        private String proFileStr = "template";
    
        public PropertiesUtil() {
            //properties文件的路径
            String templatePath = System.getProperty("user.dir") + File.separator + "src\\" + proFileStr + ".properties";
            if (prop == null) {
                prop = new Properties();
                File f = new File(templatePath);
                FileInputStream in = null;
                try {
                    in = new FileInputStream(f);
                    prop.load(in);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    
        public static synchronized PropertiesUtil getInstance() {
            if (prop == null) {
                instance = new PropertiesUtil();
            }
            return instance;
        }
    
        public String getProperties(String key, String defaultVal) {
            return prop.getProperty(key) == null ? defaultVal : prop.getProperty(key);
        }
    }

#### 2、template.properties文件 ####

usname=root
    password=123456

#### 3、测试类Main.java文件 ####

public class Main { 
        public static void main(String[] args) {
            String usname = PropertiesUtil.getInstance().getProperties("usname","zhangsan");
            System.out.println(usname);
        }
    }

输出

#如果没有获取到相应的值，使用默认值
    root