001    /*
002     * Copyright © 2008, 2012 Pedro Agulló Soliveres.
003     * 
004     * This file is part of DirectJNgine.
005     *
006     * DirectJNgine is free software: you can redistribute it and/or modify
007     * it under the terms of the GNU Lesser General Public License as published by
008     * the Free Software Foundation, either version 3 of the License.
009     *
010     * Commercial use is permitted to the extent that the code/component(s)
011     * do NOT become part of another Open Source or Commercially developed
012     * licensed development library or toolkit without explicit permission.
013     *
014     * DirectJNgine is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
017     * GNU Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public License
020     * along with DirectJNgine.  If not, see <http://www.gnu.org/licenses/>.
021     * 
022     * This software uses the ExtJs library (http://extjs.com), which is 
023     * distributed under the GPL v3 license (see http://extjs.com/license).
024     */
025    
026    package com.softwarementors.extjs.djn;
027    
028    import java.lang.reflect.Field;
029    
030    import edu.umd.cs.findbugs.annotations.Nullable;
031    
032    
033    public final class ClassUtils {
034      private ClassUtils() {
035        // Disable class instantiation
036      }
037    
038      // Returns null if field does not exist
039      @Nullable public static Class<?> getFieldType( Class<?> cls, String field ) {
040        assert cls != null;
041        assert field != null;
042        
043        Class<?> vClass = cls;
044        Class<?> fieldType = null;
045        while(true) {
046          Field[] fields = vClass.getDeclaredFields();
047          for( Field f : fields ) {
048            if( f.getName().equals(field)) {
049              fieldType = f.getType();
050              return fieldType;
051            }
052          }
053          
054          vClass = vClass.getSuperclass();
055          if( vClass.equals(Object.class) ) {
056            return null;
057          }
058        }
059      }
060      
061      public static boolean isNumericType( Class<?> cls ) {
062        assert cls != null;
063      
064        if( cls== float.class || cls == double.class || cls == byte.class || cls == short.class || cls == int.class || cls == long.class) {
065          return true;
066        }
067        
068        Class<?> currentClass = cls;
069        while( currentClass != null ) {
070          if( currentClass.equals(Number.class) )
071            return true;
072          currentClass = currentClass.getSuperclass();        
073        }
074        return false;
075      }
076    
077      // JDK 1.4 does not implement Class.getSimpleName()
078      public static String getSimpleName( Class<?> cls ) {
079        assert cls != null;
080        
081        String result = cls.getName();
082        
083        // Special case: inner classes!
084        int simpleNameStart = result.lastIndexOf("$");
085        if( simpleNameStart >= 0 ) {
086          simpleNameStart++; // Skip the "$"
087          // Need to skip the digits immediately after the "$"
088          for( ; simpleNameStart < result.length(); simpleNameStart++ ) {
089            if( !Character.isDigit(result.charAt(simpleNameStart)) ) {
090              return result.substring(simpleNameStart);
091            }
092          }
093        }
094        else {
095          simpleNameStart = result.lastIndexOf( ".");
096          if( simpleNameStart >= 0) {
097            return result.substring(simpleNameStart+1);
098          }
099        }
100        return result;
101      }
102    
103      // Note: would be nice to make recursive, so that we can handle array of array of array of ...,
104      //       but in reality pretty-printing just one-dimensional arrays is ok
105      public static String getNicePrintableName( Class<?> cls ) {
106        assert cls != null;
107        
108        Class<?> type = cls;
109        if( cls.isArray() ) {
110          type = cls.getComponentType();
111        }
112        
113        String typeName = type.getName();
114        if( typeName.startsWith( "java.lang") ) {
115          typeName = getSimpleName(type);
116        }
117        
118        if( cls.isArray() ) {
119          typeName += "[]";
120        }
121        return typeName;
122      }
123      
124    }