webpath.java

用来下载网上图片

package downLoadImage;
import java.net.*;
import java.util.regex.*;
class WebPath {
    private String web="";
    protected URL website;
    String urlPath;
    //private static String regex_1="^(http://)[^\\s]+";
   // private static String regex_2="^(/|[^(\\.|\\s)])[^\\s]+";
   // private static String regex_3="^(\\.\\./)(\\.\\./)*[^\\s]+";
    private static String regex_4="[^/]+/(\\.\\./)";
    public WebPath(String p,String w){
    	urlPath=p;
    	web=w;
    	trimPath();
    }

    public WebPath(String p,URL w){
    	urlPath=p;website=w;
    	trimPath();
    }
    
	public URL getURL(){
		/*
		try{
		if(Pattern.matches(regex_1, urlPath))
			return new URL(urlPath);
		else if(Pattern.matches(regex_2, urlPath)){
			return new URL( web+(urlPath.charAt(0)=='/'?urlPath.substring(1, urlPath.length()):urlPath) );
		}else if(Pattern.matches(regex_3, urlPath)){
			return new URL(getdefinitePath(web+urlPath));
		}
		}catch(MalformedURLException e){
			return null;
		}
		return null;
		*/
		try{
			
			if(urlPath.startsWith("http"))
				return new URL(urlPath);
			
			URL cur=new URL(website,urlPath);
			return cur;
		}catch (MalformedURLException me) {
			System.out.println("没有找到网站");
			return null;
		}
		
	}
	private void trimPath(){
		if(urlPath.startsWith("/"))
			urlPath=urlPath.substring(1, urlPath.length());

	}
	
	
	public String getURLToString(){
		
		/*
		if(Pattern.matches(regex_1, urlPath)){
			return urlPath;
		}
		else if(Pattern.matches(regex_2, urlPath)){
			return web+(urlPath.charAt(0)=='/'?urlPath.substring(1, urlPath.length()):urlPath);
		}else if(Pattern.matches(regex_3, urlPath)){		
			return getdefinitePath(web+urlPath);
		}else{
			return null;
		}
		*/
		
		if(urlPath.startsWith("http"))
			return urlPath;
		
		try{
			URL cur=new URL(website,urlPath);
			return cur.toString();
		}catch (MalformedURLException me) {
			System.out.println("没有找到网站");
			return null;
		}

		
	}
	
	public String getParent(){
	   String s=getdefinitePath(web+urlPath);
	   return s.substring(0, s.lastIndexOf("/")+1);
	}
	
	private String getdefinitePath(String s){
         Pattern p=Pattern.compile(regex_4, Pattern.CASE_INSENSITIVE);
         Matcher m=p.matcher(s);
         
         if(m.find()){
        	  StringBuffer sb=new StringBuffer();
        	  m.appendReplacement(sb, "");
              m.appendTail(sb);
              return getdefinitePath(sb.toString());
         }else{
        	 return s;
         }

	}
	
	 public String getCurrentURL(){
		 if (urlPath==null)
			 return null;
		 else{
			 char c;
			 int directory=urlPath.lastIndexOf("/");
			 if(directory<0)
				 return WebInfo.Prefix;
			 StringBuffer sb=new StringBuffer();
			 for(int i=0;i<directory;i++){
				 c=urlPath.charAt(i);
				 if(c>='a'&&c<='z'||c>='A'&&c<='Z'||c>='0'&&c<='9')
					 sb.append(c);
			 }
			 return sb.toString();
		 }
	 }

	/*
	public static void main(String s[]){
		String str="../av/index.htm";		
		WebPath wp=new WebPath(str);
		wp.setWeb("http://www.freesummer.cn/abc/aa/");
		System.out.println(wp.getURLToString());
		System.out.println(wp.getParent());
	}
	*/
}