java读取properties的工具类PropertiesUtil

 package org.properties.util;

 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;
     }
     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) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } finally {
             try {
                 is.close();
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
         return value;
     }

     public Properties getProperties() {
         Properties p = new Properties();
         InputStream is = null;
         try {
             is = PropertiesUtil.class.getClassLoader().getResourceAsStream(
                     properiesName);
             p.load(is);
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } finally {
             try {
                 is.close();
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
         return p;
     }

     public void writeProperty(String key, String value) {
         InputStream is = null;
         OutputStream os = null;
         Properties p = new Properties();
         try {
             is = new FileInputStream(properiesName);
             p.load(is);
             os = new FileOutputStream(PropertiesUtil.class.getClassLoader().getResource(properiesName).getFile());

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

     }

 }