将属性文件以key-value值形式输出的工具类

浅浅的花香味﹌ 2022-08-21 13:44 127阅读 0赞

PropertyUtil .java

package com.lmb.util;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.Enumeration;
    import java.util.HashMap;
    import java.util.Properties;
    import java.util.Set;
    
    
    
    
    public class PropertyUtil {
        
        private HashMap<String, String> map = null;
    
        private HashMap<String, String> reverseMap = null;
    
        private String fileDir = "";  
    
        /**
         * 功能描述：获取fileDir文件的内容，将其以key-value的形式解析到一个map中
         * @param fileDir 文件名
         */
        public PropertyUtil(String fileDir) {
            this.fileDir = fileDir;
            map = new HashMap<String, String>();
            try {
                String key = "";
                String value = "";
                Properties props = new Properties();
                //得到fileDir文件的输入流并将其load到我们生成的Properties对象中
                props.load(PropertyUtil.class.getClassLoader()
                        .getResourceAsStream(fileDir));
                //遍历这个Properties对象，将对象内容以key-value的形式解析到map中
                Enumeration enumFile = props.keys();
                for (int i = 0; i < props.size(); i++) {
                    key = (String) enumFile.nextElement();
                    value = props.getProperty(key);
                    map.put(key, value);
                }
            } catch (IOException e) {
                System.out.println("I/O error occurs when reading the file");
                e.printStackTrace();
            }
        }
    
        /**
         * 功能描述：获取fileDir文件的内容，将其以value-key的反转形式解析到一个map中
         * @param fileDir 文件名
         */
        public void reverse() {
            reverseMap = new HashMap<String, String>();
            try {
                String key = "";
                String value = "";
                Properties props = new Properties();
                props.load(PropertyUtil.class.getClassLoader()
                        .getResourceAsStream(fileDir));
                Enumeration enumFile = props.keys();
                for (int i = 0; i < props.size(); i++) {
                    key = (String) enumFile.nextElement();
                    value = props.getProperty(key);
                    reverseMap.put(value, key);//map.put(key, value)
                }
            } catch (IOException e) {
                System.out.println("I/O error occurs when reading the file");
                e.printStackTrace();
            }
        }
    
        /**
         * 功能描述：通过key获取到该key对应的value值
         * @param key
         * @return value
         */
        public String getValueByKey(String key) {
            return (String) map.get(key);
        }
    
        /**
         * 功能描述：获取map集合的所有key值
         * @return
         */
        public ArrayList getKeyList() {
            Set keySet = map.keySet();
            Object[] keyArray = keySet.toArray();
            ArrayList<String> keyList = new ArrayList<String>();
            for (int i = 0; i < keyArray.length; i++) {
                String tempKey = (String) keyArray[i];
                keyList.add(tempKey);
            }
            return keyList;
        }
    
        /**
         * 功能描述：获取反转map中key对应的value值（也就是正常情况下value对应的key）
         * @param key
         * @return
         */
        public String getReverseValueByKey(String key) {
            if (reverseMap==null){
                reverse();
                return (String) reverseMap.get(key);
            }else{
                return (String) reverseMap.get(key);
            }
        }
    
        /**
         * test
         * @param args
         */
        public static void main(String[] args) {
            System.out.println("________test start!______");
            PropertyUtil pu = new PropertyUtil("user.properties");
            for (int i = 0; i < pu.getKeyList().size(); i++) {
                System.out.println("   " + pu.getKeyList().get(i) + "="
                        + pu.getValueByKey((String) pu.getKeyList().get(i)));
            }
            System.out.println(pu.getValueByKey("USERNAME").trim());
            System.out.println("_________test end!_______");
        }
    }

运行结果：

![这里写图片描述][20160503214617247]

[20160503214617247]: /images/20220724/932ef4009a3d4ef999a6f56afd3e0738.png