make JSON support regex JAVA-57

erh · erh · commit 48fbd2ad5b3d · 2009-11-30T23:27:45.000-05:00
diff --git a/src/main/com/mongodb/Bytes.java b/src/main/com/mongodb/Bytes.java
@@ -186,6 +186,19 @@ public static int patternFlags( String flags ){
         return fint;
     }
 
+    public static int getFlag( char c ){
+        Flag flag = Flag.getByCharacter( c );
+        if ( flag == null )
+            throw new IllegalArgumentException( "unrecognized flag: " + c );
+
+        if ( flag.unsupported != null ){
+            _warnUnsupported( flag.unsupported );
+            return 0;
+        }
+        
+        return flag.javaFlag;
+    }
+
     /** Converts Java regular expression flags into a string of flags for the database
      * @param flags Java flags
      * @return the flags for the database
diff --git a/src/main/com/mongodb/util/JSON.java b/src/main/com/mongodb/util/JSON.java
@@ -5,6 +5,7 @@
 import com.mongodb.*;
 import java.text.*;
 import java.util.*;
+import java.util.regex.*;
 
 /**
  *   Helper methods for JSON serialization and de-serialization
@@ -146,6 +147,11 @@ public static void serialize( Object o , StringBuilder buf ){
             return;
         }
 
+        if (o instanceof Pattern) {
+            buf.append("/").append(o.toString()).append("/").append(Bytes.patternFlags( ((Pattern)o).flags() ));
+            return;
+        }
+
         throw new RuntimeException( "json can't serialize type : " + o.getClass() );
     }
 
@@ -230,6 +236,9 @@ public Object parse() {
         case '{':
             value = parseObject();
             break;
+        case '/':
+            value = parsePatter();
+            break;
         default:
             throw new JSONParseException(s, pos);
         }
@@ -265,6 +274,31 @@ public DBObject parseObject() {
 
         return obj;
     }
+    
+    public Pattern parsePatter(){
+        read( '/' );
+        
+        StringBuilder buf = new StringBuilder();
+        
+        char current = read();
+        while( current != '/'){
+            buf.append( current );
+            current = read();
+        }
+
+        int flags = 0;
+
+        while ( pos < s.length() ){
+            current = s.charAt( pos );
+            if ( Character.isWhitespace( current ) ||
+                 ! Character.isLetter( current ) )
+                break;
+            flags |= Bytes.getFlag( current );
+            current = read();
+        }
+
+        return Pattern.compile( buf.toString() , flags );
+    }
 
     /**
      * Read the current character, making sure that it is the expected character.
@@ -281,6 +315,12 @@ public void read(char ch) {
         pos++;
     }
 
+    public char read(){
+        if ( pos >= s.length() )
+            throw new IllegalStateException( "string done" );
+        return s.charAt( pos++ );
+    }
+
     /** 
      * Read the current character, making sure that it is a hexidecimal character.
      *
diff --git a/src/test/com/mongodb/util/JSONTest.java b/src/test/com/mongodb/util/JSONTest.java
@@ -18,6 +18,8 @@
 
 package com.mongodb.util;
 
+import java.util.regex.*;
+
 import com.mongodb.*;
 
 import org.testng.annotations.Test;
@@ -244,6 +246,21 @@ public void testEscape1(){
         _escapeChar( "\\" );
     }
 
+   @org.testng.annotations.Test
+   public void testPattern() {
+       String x = "^Hello$";
+       String y = "/" + x + "/i";
+
+       Pattern pattern = Pattern.compile( x , Pattern.CASE_INSENSITIVE);
+       assertEquals( y , JSON.serialize(pattern));
+
+       BasicDBObject a = new BasicDBObject( "x" , pattern );
+       assertEquals( "{ \"x\" : " + y + "}" , a.toString() );
+
+       DBObject b = (DBObject)JSON.parse( a.toString() );
+       assertEquals( a.toString() , b.toString() );
+   }
+
 
 
     public static void main( String args[] ){
