java 配置文档工具类

package tm.vision.common;

import org.apache.log4j.Logger;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
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.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Properties;
import java.util.Scanner;


public final class ConfigUtils {

    private static Logger logger = Logger.getLogger(ConfigUtils.class);

    
    private ConfigUtils() {
    }

    
    public static String getConfig(final InputStream stream, final String key) {
        return Objects.requireNonNullElse(getProperties(stream).getProperty(key), "");
    }

    
    public static String getConfig(final String fileName, final String key) {
        return Objects.requireNonNullElse(getProperties(fileName).getProperty(key), "");
    }

    
    public static void setConfig(final String fileName, final String key, final String val) {
        List list = new ArrayList<>();
        try (Scanner scanner = new Scanner(new FileInputStream(fileName), StandardCharsets.UTF_8)) {
            while (scanner.hasNext()) {
                String string = scanner.nextLine();
                if (string.startsWith(key + "=") || string.startsWith(key + " =")) {
                    list.add(key + "=" + val);
                    continue;
                }
                list.add(string);
            }
        } catch (IOException e) {
            logger.error("read config fail, filename = " + fileName);
        }

        try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new
                BufferedOutputStream(new FileOutputStream(fileName)), StandardCharsets.UTF_8))) {
            for (String string : list) {
                writer.write(string);
                if (list.indexOf(string) != list.size() - 1) {
                    writer.newline();
                }
            }
        } catch (IOException e) {
            logger.error("write config fail, filename = " + fileName);
        }
    }

    
    public static void setConfig(final String key, final String val) {
        setConfig(System.getProperty("user.dir") + "/setting/config.properties", key, val);
        logger.info("key = " + key + ", val = " + val);
    }

    
    public static String getStringConfig(final String key, final String defaultVal) {
        String val = getConfig(System.getProperty("user.dir") + "/setting/config.properties", key);
        if (val == null || val.isBlank()) {
            val = defaultVal;
            logger.info("get config is null! key =" + key);
        }
        return val;
    }

    
    public static int getIntegerConfig(final String key, final int defaultVal) {
        String val = getConfig(System.getProperty("user.dir") + "/setting/config.properties", key);
        int ret = defaultVal;
        // 格式为数字
        if (val.matches("^[0-9]\d*$")) {
            ret = Integer.parseInt(val);
        }
        return ret;
    }

    
    public static String getPathConfig(final String key, final String defaultVal) {
        String val = getConfig(System.getProperty("user.dir") + "/setting/config.properties", key);
        if (val == null || val.isBlank() || !new File(val).exists()) {
            val = defaultVal;
        }
        return val;
    }

    
    private static Properties getProperties(final String fileName) {
        Properties properties = new Properties();
        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(
                new BufferedInputStream(new FileInputStream(fileName)), StandardCharsets.UTF_8))) {
            properties.load(bufferedReader);
        } catch (IOException e) {
            logger.error("read config fail, filename = " + fileName);
        }
        return properties;
    }

    
    private static Properties getProperties(final InputStream stream) {
        Properties properties = new Properties();

        try {
            properties.load(stream);
        } catch (IOException e) {
            logger.error("read config fail in inputstream");
        } finally {
            try {
                stream.close();
            } catch (IOException e) {
                logger.error("close read config file fail");
            }
        }
        return properties;
    }
}