Search by using java. lang. String that comes with java

Which of the following is better for searching and creating indexes using the matching function provided by java? Run it.

 

Package ch2.lucenedmo. test2;

Import java. io .*;
Import java. util .*;

Import org. apache. lucene. index .*;
Import org. apache. lucene. search .*;

Public class Search
{
Private String INDEX_STORE_PATH = "d:/index ";

Public void StringSearch (String keyword, String searchDir)
{
File filesDir = new File (searchDir );
File [] files = filesDir. listFiles ();
// HashMap saves the file name and matches this book's object
Map rs = new HashMap ();
Date beginTime = new Date ();
For (int I = 0; I <files. length; I ++)
{
Int hits = 0;
Try
{
BufferedReader br = new BufferedReader (new FileReader (files [I]);
StringBuffer sb = new StringBuffer ();
String line = br. readLine ();
While (line! = Null)
{
SB. append (line );
Line = Br. Readline ();
}
BR. Close ();
String stringtosearch = sb. tostring ();
Int fromindex =-Keyword. Length ();
// For me, I didn't understand this sentence at the beginning. It turned out that I had been searching for a match, found one, hits and 1, and finally searched.
While (fromIndex = stringToSearch. indexOf (keyword, fromIndex + keyword. length ()))! =-1) // read more
{
Hits ++;
}
// Add the file name and matching times to HashMap
Rs. put (files [I]. getName (), new Integer (hits ));
}
Catch (IOException e)
{
E. printStackTrace ();
}
}
// Obtain the object
Iterator it = rs. keySet (). iterator ();
While (it. hasNext ())
{
String filename = (string) it. Next ();
Integer hits = (integer) Rs. Get (filename); // obtain the value corresponding to the file name
System. Out. println ("find" + hits. intvalue () + "matches in" + filename );
}
Date endtime = new date ();
Long timesearch = endtime. gettime ()-begintime. gettime ();
System. Out. println ("the time for string search is" + timesearch + "Ms ");
}
Public static void main (string [] ARGs ){
Search search = new search ();
Search. stringsearch ("rabbit", "d:/textfolder ");

}

}

How to Use hashmap? Let's take a look at this example.

 

Package bag;
Import java. util .*;
// Key-value pairs are stored in HashMap and can be directly obtained through keys.
Class Hash
{
Hash ()
{
HashMap hash = new HashMap ();
Hash. put ("001", "Beijing"); // "001" is the key, and "Beijing" is the value.
Hash. put ("002", "Shanghai ");
Hash. put ("003", "Tianjin ");
Iterator it = hash. keySet (). iterator (); // This is the key object.
While (it. hasNext ())
{
System. out. println ("it. Next data value:" + get (it. next (); // obtain the value corresponding to the key.
}
}
}

Iterate. Iterator! How to use it? Compared with the following program, we should find that

 

Import java. util .*;
Public class Iterate {
Public static void main (String args []) {
String elements [] = {"Irish Setter", "Poodle ",
"English Setter", "Gordon Setter", "Pug "};
Set set = new HashSet (Arrays. asList (elements ));
Iterator iter = set. iterator ();
While (iter. hasNext ()){
System. out. println (iter. next ());
}
}
}