properties文件读写工具类

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Properties;


public class PropertiesUtil {
    
    private String properiesName = "";

    public PropertiesUtil() {

    }
    
    public PropertiesUtil(String fileName) {
        this.properiesName = fileName;
    }
    
    /**
     * 按key获取值
     * @param key
     * @return
     */
    public String readProperty(String key) {
        String value = "";
        InputStream is = null;
        try {
            is = PropertiesUtil.class.getClassLoader().getResourceAsStream(properiesName);
            Properties p = new Properties();
            p.load(is);
            value = p.getProperty(key);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return value;
    }

    /**
     * 获取整个配置信息
     * @return
     */
    public Properties getProperties() {
        Properties p = new Properties();
        InputStream is = null;
        try {
            is = PropertiesUtil.class.getClassLoader().getResourceAsStream(properiesName);
            p.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return p;
    }

    /**
     * key-value写入配置文件
     * @param key
     * @param value
     */
    public void writeProperty(String key, String value) {
        InputStream is = null;
        OutputStream os = null;
        Properties p = new Properties();
        try {
            is = new FileInputStream(properiesName);
//            is = PropertiesUtil.class.getClassLoader().getResourceAsStream(properiesName);
            p.load(is);
//            os = new FileOutputStream(PropertiesUtil.class.getClassLoader().getResource(properiesName).getFile());
            os = new FileOutputStream(properiesName);

            p.setProperty(key, value);
            p.store(os, key);
            os.flush();
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != is)
                    is.close();
                if (null != os)
                    os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

    public static void main(String[] args) {
        // sysConfig.properties(配置文件)
        PropertiesUtil p = new PropertiesUtil("sysConfig.properties");
        System.out.println(p.getProperties().get("db.url"));
        System.out.println(p.readProperty("db.url"));
        PropertiesUtil q = new PropertiesUtil("resources/sysConfig.properties");
        q.writeProperty("myUtils", "wang");
        System.exit(0);
    }

}

　　　　　　//加载properties配置文件===>Properties
            Properties properties = new Properties();
            InputStream in = new FileInputStream("src/bean.properties");
            properties.load(in);
            //根据key到配置文件中获取对应的value
            String classname = properties.getProperty(key);

String BUCKET_NAME = PropertiesUtil.getProperty("fileOperator.properties","BucketName"); 

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.Map.Entry;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;

public class PropertiesUtil {
    public PropertiesUtil() {
    }
　　　//加载输入流，返回Propeties
    public static Properties load(InputStream is) throws IOException {
        Properties prop = new Properties();
        prop.load(is);
        return prop;
    }
　　//通过文件路径加载文件，形成输入流，加载输入流，返回properties
    public static Properties load(String path) throws IOException {
        InputStream is = PropertiesUtil.class.getClassLoader().getResourceAsStream(path);
        if (is == null) {
            throw new IOException(path + " 文件找不到。");
        } else {
            Properties var2;
            try {
                var2 = load(is);
            } finally {
                IOUtils.closeQuietly(is);
            }

            return var2;
        }
    }

    public static void update(String path, Map<String, String> kvMap) throws IOException {
        URL url = PropertiesUtil.class.getResource(path);

        try {
            if (url != null && null != url.toURI()) {
                String absolutePath = url.toURI().getPath();
                updateAbsolutePath(absolutePath, kvMap);
            }
        } catch (URISyntaxException var4) {
            var4.printStackTrace();
        }

        throw new IOException("file: " + path + " can not found.");
    }

    public static void updateAbsolutePath(String absolutePath, Map<String, String> kvMap) throws IOException {
        File propFile = new File(absolutePath);
        InputStream in = null;
        FileOutputStream out = null;

        try {
            if (!propFile.exists()) {
                propFile.createNewFile();
            }

            in = FileUtils.openInputStream(propFile);
            Properties props = load((InputStream)in);
            Set<Entry<String, String>> kvSet = kvMap.entrySet();
            Iterator i$ = kvSet.iterator();

            while(i$.hasNext()) {
                Entry<String, String> entry = (Entry)i$.next();
                props.setProperty((String)entry.getKey(), (String)entry.getValue());
            }

            out = FileUtils.openOutputStream(propFile);
            props.store(out, (String)null);
        } finally {
            IOUtils.closeQuietly(in);
            IOUtils.closeQuietly(out);
        }
    }
　　//通过加载文件，指定key，获得value
    public static String getProperty(String path, String key) throws NotFoundException {
        try {
            Properties pro = load(path);
            return pro.getProperty(key);
        } catch (IOException var4) {
            String message = "获取资源文件" + path + "的key(" + key + ")失败,原因:" + var4.getCause();
            Logger.errorX(PropertiesUtil.class, message);
            throw new NotFoundException(message);
        }
    }
}