How to search files by wildcard expression

Question

how to search files by wildcard expression,
and list all of them?
for example:
search file as image*.jpg or ima231*.jpg.
please give me some code to study.
thanks in advance.

Answer 1

following code is a filename filter that support '*' and '?', hope it helps.
import java.util.*;
class MyFilenameFilter {
  static public void main(String args[]){
    byte[] in2=new byte[255];
    String filter=null,fileName=null;
    try{
      while(1>0){
        System.out.print("filter (ex: abc*def?.do?):");
        in2=new byte[255];
        System.in.read(in2);
        if((new String(in2)).trim().length()>0) filter=(new String(in2)).trim();  
        System.out.print("filename (ex: abcerdefi.doc):");
        in2=new byte[255];
        System.in.read(in2);
        if((new String(in2)).trim().length()>0) fileName=(new String(in2)).trim();
        System.out.println("filter="+filter+",filename="+fileName+",result="+(chkfn(filter,fileName)? "Matched":"Not Matched"));
    } catch(Exception e){
         e.printStackTrace();
  static boolean chkfn(String chk,String fn)  {//ex:chk=*fg?gh fn=tdiekd.exe, or ex:chk=test.csv fn=k.csv
    boolean rtn=false;
    int x3=0,x4=0,x4Head=0,x4Tail=0;
    if(chk.endsWith(".*") && fn.indexOf(".")==-1) chk=chk.substring(0,chk.length()-2);
    if(chk.endsWith(".") && fn.indexOf(".")==-1) chk=chk.substring(0,chk.length()-1);
    if(fn==null || fn.length()<1) return false;
    if(chk==null) return true;
    if(chk.length()<1 || chk.equals("*") || chk.equals(".") || chk.equals("*.*")) return true;
    int chkLength=chk.length();
    int fnLength=fn.length();
    int newx4Head=-1,newx4Tail=-1;
    int last_asterisk=chk.lastIndexOf("*");
    int first_asterisk=chk.indexOf("*");
    int asteriskCount=0,aindex[]=new int[20],tmp[]=null,index1=-1,cCount=0;
    String cString[]=new String[20];
    chk=chk.toUpperCase();
    fn=fn.toUpperCase();
    char c='0';
    boolean found=false;
    String chkString="";
    //replace each '**' with '*' befroe further action
    while(chk.indexOf("**")!=-1){
      chk=replace(chk,"**","*");
    chkLength=chk.length();
    last_asterisk=chk.lastIndexOf("*");
    first_asterisk=chk.indexOf("*");
    //count the '*' count
    x3=0;
    while(x3<chkLength){
      if(chk.charAt(x3)=='*'){aindex[asteriskCount]=x3; asteriskCount++;}
      x3++;
    //to get the cString[], each string next to '*'
    StringTokenizer st=new StringTokenizer(chk,"*");
    while(st.hasMoreElements()){
      cString[cCount]=st.nextToken(); cCount++;
    //first check the head and the tail
    if(first_asterisk>0){//first_asterisk!=-1 && first_asterisk!=0
       chkString=chk.substring(0,first_asterisk);
       if(chkString.indexOf("?")!=-1){
             if(fnLength>first_asterisk-1){
               if(cmp(chkString,fn.substring(0,first_asterisk))==false) return false;
             } else return false;
       } else if(!fn.startsWith(chkString)) return false;
       x4Head=chkString.length()+1;
    } else if(first_asterisk==0) {
         x4Head=findMatch(cString[0],fn);
         if(x4Head==-1) return false;
    if(last_asterisk!=chkLength-1 && last_asterisk!=-1){
       chkString=chk.substring(last_asterisk+1,chkLength);
       if(chkString.indexOf("?")!=-1){
             if(fnLength-(chkLength-last_asterisk)+1>-1){
               if(cmp(chkString,fn.substring(fnLength-(chkLength-last_asterisk)+1,fnLength))==false) return false;
             } else return false;
       } else if(!fn.endsWith(chkString)) return false;
       x4Tail=fnLength-chkString.length();
    } else if(last_asterisk==chkLength-1) {
         newx4Tail=findMatch(cString[cCount-1],fn.substring(x4Head));
         x4Tail=x4Head+newx4Tail+cString[cCount-1].length();
    if(asteriskCount>1){
      int oldx4Head=x4Head;
      if(last_asterisk!=chkLength-1) {
           if(cString[cCount-2].indexOf("?")==-1){
          x4Tail=fn.substring(x4Head,x4Tail).lastIndexOf(cString[cCount-2]);
          if(x4Tail!=-1) x4Tail=x4Tail+cString[cCount-2].length();
      if(first_asterisk!=0){
        if(cString[1].indexOf("?")==-1){
          x4Head=fn.substring(x4Head).indexOf(cString[1]);
          if(x4Head!=-1) x4Head=oldx4Head+x4Head;
      //before of this, x4head and x4tail are adjusted according to '*', and now it will also adjusted according to '?'
      if(x4Head>-1 && x4Tail>x4Head &&
         chk.substring(aindex[0]+1,aindex[asteriskCount-1]).indexOf("*")==-1 &&
         chk.substring(aindex[0]+1,aindex[asteriskCount-1]).length()!=x4Tail-x4Head &&
         chk.substring(aindex[0]+1,aindex[asteriskCount-1]).indexOf("?")!=-1){
           newx4Head=-1;
           newx4Head=findMatch(chk.substring(aindex[0]+1,aindex[asteriskCount-1]),fn.substring(x4Head,x4Tail));
           if(newx4Head>-1) {
             x4Head=x4Head+newx4Head;
             x4Tail=x4Head+aindex[asteriskCount-1]-(aindex[0]+1);
      if(x4Head>-1 && x4Tail>x4Head) return chkfn(chk.substring(aindex[0]+1,aindex[asteriskCount-1]),fn.substring(x4Head,x4Tail));
      else return false;
    } else if(asteriskCount==0){
          if(fnLength==chkLength) return cmp(chk,fn);
            else return false;
    return true;
  static public boolean cmp(String chkString,String fnString){//1.no '*', 2.only for two strings having same length 3.two  strings are uppercase before call this method
    boolean rtn=false;
    int clength=chkString.length(),flength=fnString.length();
    if(clength!=flength) return false;
    for(int i=0;i<clength;i++){
      if(chkString.charAt(i)!='?' && chkString.charAt(i)!=fnString.charAt(i)) return false;
    return true;
  static public int findMatch(String chkString,String fnString){//to find out the correct index postion for the string between two '*'
    int rtn=-1;
    boolean found=false;
    int chkLength=chkString.length();
    int fnLength=fnString.length();
    if(chkLength>fnLength) return -1;
    for(int i=0;i<fnLength-chkLength+1;i++){
      found=true;
      for(int j=0;j<chkLength;j++){
        if(chkString.charAt(j)!='?' && chkString.charAt(j)!=fnString.charAt(j+i)) {found=false; break;}
      if(found) return i;
    return rtn;
  public static String replace(String s, String s1, String s2) {
      if(s!=null && s1!=null && s2!=null){
        int i = 0;
        int j = s.length();
        int k = s1.length();
        int l = s2.length();
        do {
            String s3 = "";
            i = s.indexOf(s1, i);
            if(i == -1)
                break;
            StringBuffer stringbuffer = new StringBuffer(s.substring(0, i));
            s3 = s.substring(i + k);
            stringbuffer.append(s2).append(s3);
            s = stringbuffer.toString();
            j = s.length();
            i += l;
        } while(i <= j);
      return s;
}