Java工具类

2018-01-17

日期工具类

字符串与日期的转换：

import java.text.SimpleDateFormat;
import java.util.Date;
public class DateUtil {
    //日期转字符
	public static String formatDate(Date date,String format){
		String result="";
		SimpleDateFormat sdf=new SimpleDateFormat(format);
		if(date!=null){
			result=sdf.format(date);
		}
		return result;
	}
	
	//字符转日期
	public static Date formatString(String str,String format) throws Exception{
		if(StringUtil.isEmpty(str)){
			return null;
		}
		SimpleDateFormat sdf=new SimpleDateFormat(format);
		return sdf.parse(str);
	}
	//获取当前时间
	public static String getCurrentDateStr()throws Exception{
		Date date=new Date();
		SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMddhhmmss");
		return sdf.format(date);
	}
}

数据库连接工具类

public class DbUtil {
	//获得连接
	public Connection getCon() throws Exception{
		Class.forName(PropertiesUtil.getValue("jdbcName"));
		Connection con=DriverManager.getConnection(PropertiesUtil.getValue("dbUrl"), PropertiesUtil.getValue("dbUserName"), PropertiesUtil.getValue("dbPassword"));
		return con;
	}
	//关闭连接
	public void closeCon(Connection con)throws Exception{
		if(con!=null){
			con.close();
		}
	}
	
	
}

加密工具类

public class MD5Util {
	public static String EncoderPwdByMd5(String str) throws NoSuchAlgorithmException, UnsupportedEncodingException{
		MessageDigest md5=MessageDigest.getInstance("MD5");
		BASE64Encoder base64en=new BASE64Encoder();
		return base64en.encode(md5.digest(str.getBytes("utf-8")));
	}
}

读取配置文件

public class PropertiesUtil {
	public static String getValue(String key){
		Properties prop=new Properties();
		InputStream in=new PropertiesUtil().getClass().getResourceAsStream("/setting.properties");
		try {
			prop.load(in);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return (String)prop.get(key);
	}
}

字符串工具类

public class StringUtil {
	    public static boolean isEmpty(String str){
		if(str==null || "".equals(str.trim())){
			return true;
		}else{
			return false;
		}
	}
	
		public static boolean isNotEmpty(String str){
		if(str!=null && !"".equals(str.trim())){
			return true;
		}else{
			return false;
		}
	}
	
	    public static String formatLike(String str){
		if(isNotEmpty(str)){
			return "%"+str+"%";
		}else{
			return null;
		}
	}
}