JAVA常用方法

package com.util;   
import java.io.BufferedInputStream;    
import java.io.BufferedWriter;    
import java.io.File;    
import java.io.FileInputStream;    
import java.io.FileOutputStream;    
import java.io.FileWriter;    
import java.io.FilterInputStream;    
import java.io.IOException;    
import java.io.InputStream;    
import java.io.OutputStream;    
import java.io.PrintWriter;    
import java.net.URL;    
import java.text.SimpleDateFormat;    
import java.util.Calendar;    
import java.util.Date;    
import java.util.Enumeration;    
import java.util.HashMap;    
import java.util.Map;    
import java.util.Properties;    
import java.util.regex.Matcher;    
import java.util.regex.Pattern;    
   
public class SuperUitl {    
     
 public static void main(String[] args) {    
  System.out.println();    
 }    
     
 /**   
  * 全角转半角   
  * trr 要转换成半角的字符串   
  */   
 public static String change(String str) {    
  String outStr="";    
  String test="";    
  byte[] code = null;    
      
  for(int i=0;i<str.length();i++) {         
   try {    
    test = str.substring(i,i+1);    
    code = test.getBytes("unicode");    
   } catch(java.io.UnsupportedEncodingException e) {    
   }         
   if (code[3] == -1) {    
    code[2] = (byte)(code[2]+32);    
    code[3] = 0;          
   
    try {           
     outStr = outStr + new String(code,"unicode");    
    } catch(java.io.UnsupportedEncodingException e) {    
    }          
   } else {    
    outStr = outStr + test;    
   }    
  }    
  return outStr;     
 }    
     
 /**   
  * 根据key读取value   
  * filePath 要操作的properties文件路径   
  * key 要获得数据的key   
  */   
 public static String readValue(String filePath,String key) {    
  Properties props = new Properties();    
        try {    
         InputStream in = new BufferedInputStream (new FileInputStream(filePath));    
         props.load(in);    
         String value = props.getProperty (key);    
            return value;    
        } catch (Exception e) {    
         return null;    
        }    
 }    
     
 /**   
  * 读取properties的全部信息   
  * filePath 要操作的properties文件路径   
  */   
    public static Map readProperties(String filePath) {    
     Map map = new HashMap();    
     Properties props = new Properties();    
        try {    
         InputStream in = new BufferedInputStream (new FileInputStream(filePath));    
         props.load(in);    
            Enumeration en = props.propertyNames();    
             while (en.hasMoreElements()) {    
              String key = (String) en.nextElement();    
                    String Property = props.getProperty (key);    
                    map.put(key,Property);    
                }    
             return map;    
        } catch (Exception e) {    
         return null;    
        }    
    }    
   
    /**   
  * 写入properties信息   
  * filePath 要操作的properties文件路径   
  * key 要写入的key   
  * value 要写入的value   
  */   
    public static boolean writeProperties(String filePath,String key,String value) {    
     Properties prop = new Properties();    
     try {    
      InputStream fis = new FileInputStream(filePath);    
            //从输入流中读取属性列表（键和元素对）    
            prop.load(fis);    
            //调用 Hashtable 的方法 put。使用 getProperty 方法提供并行性。    
            //强制要求为属性的键和值使用字符串。返回值是 Hashtable 调用 put 的结果。    
            OutputStream fos = new FileOutputStream(filePath);    
            prop.setProperty(key,value);    
            //以适合使用 load 方法加载到 Properties 表中的格式，    
            //将此 Properties 表中的属性列表（键和元素对）写入输出流    
            prop.store(fos, "Update '" + key + "' value");    
            return true;    
        } catch (IOException e) {    
         return false;    
        }    
    }    
        
    /**   
  * 返回标准系统时间   
  */   
    public static String getDate() {    
  SimpleDateFormat ft=null;    
  Date date=null;    
  Calendar cl= Calendar.getInstance();    
  cl.setTime(new java.util.Date());    
  date=cl.getTime();    
  ft=new SimpleDateFormat("yyyy-MM-dd HH:mm");    
  String dateTime = ft.format(date);    
  return dateTime;    
 }    
        
    /**   
  * 从指定的字符串中提取Email   
  * content 指定的字符串   
  */   
 public static String parse(String content) {    
  String email = null;    
  if (content==null || content.length()<1) {    
   return email;    
  }    
  //找出含有@    
  int beginPos;    
  int i;    
  String token = "@";    
  String preHalf="";    
  String sufHalf = "";    
      
  beginPos = content.indexOf(token);    
  if (beginPos>-1) {    
   //前项扫描    
   String s = null;    
   i= beginPos;    
   while(i>0) {    
    s = content.substring(i-1,i);    
    if (isLetter(s))    
     preHalf = s+preHalf;    
    else   
     break;    
    i--;    
   }    
   //后项扫描    
   i= beginPos+1;    
   while( i<content.length()) {    
    s = content.substring(i,i+1);    
    if (isLetter(s))    
     sufHalf =  sufHalf +s;    
    else   
     break;    
    i++;      
   }    
   //判断合法性    
   email = preHalf + "@" + sufHalf;    
   if (isEmail(email)) {    
    return email;    
   }    
  }    
  return null;    
 }    
     
 /**   
  * 判断是不是合法Email   
  * email Email地址   
  */   
 public static boolean isEmail(String email) {    
  try {    
   if (email==null || email.length()<1 || email.length()>256) {    
    return false;    
   }    
       
   String check = "^([0-9a-zA-Z]+[_.0-9a-zA-Z-]+)@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2,3})$";    
   Pattern regex = Pattern.compile(check);    
   Matcher matcher = regex.matcher(email);    
   boolean isMatched = matcher.matches();    
   if(isMatched) {    
    return true;    
   } else {    
    return false;    
   }    
  } catch (RuntimeException e) {    
   return false;    
  }     
 }    
     
 /**   
  * 判断是不是合法字符   
  * c 要判断的字符   
  */   
 public static boolean isLetter(String c) {    
  boolean result = false;    
      
  if (c==null || c.length()<0) {    
   return false;    
  }    
  //a-z     
  if (c.compareToIgnoreCase("a")>=0 && c.compareToIgnoreCase("z")<=0) {    
   return true;    
  }    
  //0-9    
  if (c.compareToIgnoreCase("0")>=0 && c.compareToIgnoreCase("9")<=0) {    
   return true;    
  }    
  //. - _    
  if (c.equals(".") || c.equals("-") || c.equals("_") ) {    
   return true;    
  }    
  return result;     
 }    
     
 /**   
  * 删除整个目录的全部图片   
  * filePath 要删除的目录路径   
  */   
 public static boolean deleteImage(String filePath) {    
  try {    
   File file = new File(filePath);    
   File[] files = file.listFiles();    
   for(int i=0;i<files.length;i++) {    
    try {    
     //系统文件不删除    
     if(!(files[i].getName()).equalsIgnoreCase("Thumbs.db")) {    
      if(files[i].isFile()) {    
       files[i].delete();    
      } else if(files[i].isDirectory()) {    
       files[i].delete();    
      } else {    
       files[i].delete();    
      }    
     }    
    } catch (RuntimeException e) {;    
    }    
   }    
   return true;    
  } catch (RuntimeException e) {    
   return false;    
  }     
 }    
     
 /**   
  * 保存网络上的图片到指定目录   
  * filePath 要保存到本地服务器的目录   
  * imagePath 网络图片的UIL地址   
  */   
 public static boolean saveImage(String filePath,String imagePath) {    
  try {    
   if(imagePath.length()>1024 || imagePath.equals("")) {    
    return false;    
   }    
   String fileName = imagePath.substring(imagePath.lastIndexOf("/")+1,imagePath.length());    
   filePath = filePath+fileName;    
   URL url = null;    
   try {    
     url = new URL(imagePath);    
   } catch(Exception e) {    
     return false;    
   }    
   FilterInputStream in=(FilterInputStream) url.openStream();    
   File fileOut=new File(filePath);    
   FileOutputStream out=new FileOutputStream(fileOut);    
   byte[] bytes=new byte[1024];    
   int c;    
   while((c=in.read(bytes))!=-1) {    
    out.write(bytes,0,c);    
   }    
   in.close();    
   out.close();    
   return true;    
  } catch(Exception e) {     
   return false;     
  }    
 }    
     
 /**   
  * 写入日志   
  * filePath 日志文件的路径   
  * code 要写入日志文件的内容   
  */   
 public static boolean print(String filePath,String code) {    
  try {    
   File tofile=new File(filePath);    
   FileWriter fw=new FileWriter(tofile,true);    
   BufferedWriter bw=new BufferedWriter(fw);    
   PrintWriter pw=new PrintWriter(bw);    
       
   System.out.println(getDate()+":"+code);    
   pw.println(getDate()+":"+code);    
   pw.close();    
   bw.close();    
   fw.close();    
   return true;    
  } catch (IOException e) {    
   return false;    
  }    
 }    
     
 /**   
  * 判断是不是合法手机   
  * handset 手机号码   
  */   
 public static boolean isHandset(String handset) {    
  try {    
   if(!handset.substring(0,1).equals("1")) {    
    return false;    
   }    
   if (handset==null || handset.length()!=11) {    
    return false;    
   }    
   String check = "^[0123456789]+$";    
   Pattern regex = Pattern.compile(check);    
   Matcher matcher = regex.matcher(handset);    
   boolean isMatched = matcher.matches();    
   if(isMatched) {    
    return true;    
   } else {    
    return false;    
   }    
  } catch (RuntimeException e) {    
   return false;    
  }     
 }    
}