java 动态生成bean的案例

import org.assertj.core.internal.cglib.beans.BeanGenerator;

import org.assertj.core.internal.cglib.beans.BeanMap;

import java.lang.reflect.Field;

import java.lang.reflect.Method;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

/**

  * Created by wangpengzhi1 on 2018/1/2.

  */

public class BeanCeater {

  public static void main(String[] args) throws ClassNotFoundException {

   System.out.println( "Generate JavaBean" );

   Map properties = new HashMap();

   properties.put( "id" , Class.forName( "java.lang.Integer" ));

   properties.put( "name" , Class.forName( "java.lang.String" ));

   properties.put( "address" , Class.forName( "java.lang.String" ));

   Object stu = generateObject(properties);

   System.out.println( "Set values" );

   setValue(stu, "id" , 123 );

   setValue(stu, "name" , "454" );

   setValue(stu, "address" , "789" );

   System.out.println( "Get values" );

   System.out.println( ">> " + getValue(stu, "id" ));

   System.out.println( ">> " + getValue(stu, "name" ));

   System.out.println( ">> " + getValue(stu, "address" ));

   System.out.println( "Show all methods" );

   Method[] methods = stu.getClass().getDeclaredMethods();

   for (Method method : methods) {

    System.out.println( ">> " + method.getName());

   }

   System.out.println( "Show all properties" );

   Field[] fields = stu.getClass().getDeclaredFields();

   for (Field field : fields) {

    System.out.println( ">> " + field.getName());

   }

  }

  private static Object generateObject(Map properties) {

   BeanGenerator generator = new BeanGenerator();

   Set keySet = properties.keySet();

   for (Iterator i = keySet.iterator(); i.hasNext();) {

    String key = (String)i.next();

    generator.addProperty(key, (Class)properties.get(key));

   }

   return generator.create();

  }

  private static Object getValue(Object obj, String property) {

   BeanMap beanMap = BeanMap.create(obj);

   return beanMap.get(property);

  }

  private static void setValue(Object obj, String property, Object value) {

   BeanMap beanMap = BeanMap.create(obj);

   beanMap.put(property, value);

  }

}

public static void doWithFields(Class<?> clazz, ReflectionUtils.FieldCallback fc, @Nullable ReflectionUtils.FieldFilter ff) {

     Class targetClass = clazz;

     do {

       Field[] fields = getDeclaredFields(targetClass);

       Field[] var5 = fields;

       int var6 = fields.length;

       for ( int var7 = 0 ; var7 < var6; ++var7) {

         Field field = var5[var7];

         if (ff == null || ff.matches(field)) {

           try {

             fc.doWith(field);

           } catch (IllegalAccessException var10) {

             throw new IllegalStateException( "Not allowed to access field '" + field.getName() + "': " + var10);

           }

         }

       }

       targetClass = targetClass.getSuperclass();

     } while (targetClass != null && targetClass != Object. class );

   }

   private static Field[] getDeclaredFields(Class<?> clazz) {

     Assert.notNull(clazz, "Class must not be null" );

     Field[] result = (Field[])declaredFieldsCache.get(clazz);

     if (result == null ) {

       try {

         result = clazz.getDeclaredFields();

         declaredFieldsCache.put(clazz, result.length == 0 ? NO_FIELDS : result);

       } catch (Throwable var3) {

         throw new IllegalStateException( "Failed to introspect Class [" + clazz.getName() + "] from ClassLoader [" + clazz.getClassLoader() + "]" , var3);

       }

     }

     return result;

   }