properties

# properties存储的键值对格式如下
name=ashe
gender=female

前言

  Properties是java提供的api，可以用来操作键值对，常用作操作配置文件

  该文件常用后缀名为.prop或者.properties

  注意中文乱码问题比较烦，暂无全而完美的方法，遇到后再找资料解决

存取键值对的工具类

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;


public class TProperties {
	
	/** 设置键值对 */
    public static boolean set(String filePath, String key, String value) {
        Properties props = new Properties();
        props.setProperty(key, value);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(filePath);
            props.store(fos, null);
            return true;
        } catch (Exception e) {
            return false;
        } finally {
            try {
                if (fos != null) fos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

	/** 取某键对应的值 */ 
    public static String get(String filePath, String key) {
        File file;
        InputStream is = null;
        Properties properties;

        try {
            file = new File(filePath);
            if (!file.exists()) {
                return null;
            }

            is = new FileInputStream(file);

            properties = new Properties();
            properties.load(is);

            return new String(properties.getProperty(key)); // 处理中文乱码
            //            return new String(properties.getProperty(key).getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8); // 处理中文乱码

        } catch (Exception e) {
            e.printStackTrace();
            return null;

        } finally {
            try {
                if (null != is) is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

	/** 取所有键值对 */
    public static Map<String, String> getAllKV(String filePath) {
        File file;
        InputStreamReader is = null;
        Properties properties;

        try {
            file = new File(filePath);
            if (!file.exists()) {
                return null;
            }

            is = new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8);
            properties = new Properties();
            properties.load(is);

            Map<String, String> map = new HashMap<>();
            // way1: use Enumeration to visit the properties
            /*Enumeration<?> enumeration = properties.propertyNames();
            while (enumeration.hasMoreElements()) {
                String value = (String) enumeration.nextElement();
                System.out.println(value + "=" + properties.getProperty(value));
            }

            // way2: use KeySet to visit the properties
            Set<Object> keyset = properties.keySet();
            Iterator<Object> itr = keyset.iterator();
            while (itr.hasNext()) {
                String key = itr.next().toString();
                System.out.println(key + "=" + properties.getProperty(key));
            }*/

            // way3: use stringPropertyNames to visit the properties
            Set<String> keys = properties.stringPropertyNames();
            for (String key : keys) {
                map.put(key, properties.getProperty(key));
            }
            return map;

        } catch (Exception e) {
            e.printStackTrace();
            return null;

        } finally {
            try {
                if (null != is) is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}