import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;

/*
* 通過Java反射機制，動態給物件屬性賦值，並獲取屬性值
*/
public class ClassRefUtil {

/**
 * @param args
 */
public static void main(String[] args) {
    Map<String, String> valMap = new HashMap<String, String>();  
    valMap.put("userName", "michael");  
    valMap.put("age", "27");  
    valMap.put("height", "173.5");  
    valMap.put("date", "2010-10-24");  
    valMap.put("times", "1287932898276");  
    valMap.put("flag", "false");  

    ChildInfo rl = new ChildInfo(); 
    System.out.println("通過反射賦值.");  
    PublicUtil.setFieldValue(rl, valMap);  

    System.out.println("通過反射取值:");  
    int i = 0;
    Map<String, String> fieldValMap = PublicUtil.getFieldValueMap(rl); 
    for (Entry<String, String> entry : fieldValMap.entrySet()) {  
        i++;
        System.out.println("[欄位 "+i+"] ["+entry.getKey()+"]   ---   [" + entry.getValue()+"]");  
    }  
}


/** 
 * 取Bean的屬性和值對應關係的MAP 
 * @param bean 
 * @return Map 
 */ 
public static Map<String, String> getFieldValueMap(Object bean) {  
    Class<?> cls = bean.getClass();  
    Map<String, String> valueMap = new HashMap<String, String>();  
    // 取出bean裡的所有方法  
    Method[] methods = cls.getDeclaredMethods();  
    Field[] fields = cls.getDeclaredFields();  

    for (Field field : fields) {  
        try {  
            String fieldType = field.getType().getSimpleName();  
            String fieldGetName = parGetName(field.getName());  
            if (!checkGetMet(methods, fieldGetName)) {  
                continue;  
            }  
            Method fieldGetMet = cls.getMethod(fieldGetName, new Class[] {});  
            Object fieldVal = fieldGetMet.invoke(bean, new Object[] {});  
            String result = null;  
            if ("Date".equals(fieldType)) {  
                result = fmtDate((Date) fieldVal);  
            } else {  
                if (null != fieldVal) {  
                    result = String.valueOf(fieldVal);  
                }  
            }  
            valueMap.put(field.getName(), result);  
        } catch (Exception e) {  
            continue;  
        }  
    }  
    return valueMap;  

}  

/** 
 * set屬性的值到Bean 
 * @param bean 
 * @param valMap 
 */ 
public static void setFieldValue(Object bean, Map<String, String> valMap) {  
    Class<?> cls = bean.getClass();  
    // 取出bean裡的所有方法  
    Method[] methods = cls.getDeclaredMethods();  
    Field[] fields = cls.getDeclaredFields();  

    for (Field field : fields) {  
        try {  
            String fieldSetName = parSetName(field.getName());  
            if (!checkSetMet(methods, fieldSetName)) {  
                continue;  
            }  
            Method fieldSetMet = cls.getMethod(fieldSetName, field.getType());  
            String value = valMap.get(field.getName());  
            if (null != value && !"".equals(value)) {  
                String fieldType = field.getType().getSimpleName();  
                if ("String".equals(fieldType)) {  
                    fieldSetMet.invoke(bean, value);  
                } else if ("Date".equals(fieldType)) {  
                    Date temp = parseDate(value);  
                    fieldSetMet.invoke(bean, temp);  
                } else if ("Integer".equals(fieldType) || "int".equals(fieldType)) {  
                    Integer intval = Integer.parseInt(value);  
                    fieldSetMet.invoke(bean, intval);  
                } else if ("Long".equalsIgnoreCase(fieldType)) {  
                    Long temp = Long.parseLong(value);  
                    fieldSetMet.invoke(bean, temp);  
                } else if ("Double".equalsIgnoreCase(fieldType)) {  
                    Double temp = Double.parseDouble(value);  
                    fieldSetMet.invoke(bean, temp);  
                } else if ("Boolean".equalsIgnoreCase(fieldType)) {  
                    Boolean temp = Boolean.parseBoolean(value);  
                    fieldSetMet.invoke(bean, temp);  
                } else {  
                    System.out.println("not supper type" + fieldType);  
                }  
            }  
        } catch (Exception e) {  
            continue;  
        }  
    }  

}  

/** 
 * 格式化string為Date 
 * @param datestr 
 * @return date 
 */ 
private static Date parseDate(String datestr) {  
    if (null == datestr || "".equals(datestr)) {  
        return null;  
    }  
    try {  
        String fmtstr = null;  
        if (datestr.indexOf(':') > 0) {  
            fmtstr = "yyyy-MM-dd HH:mm:ss";  
        } else {  
            fmtstr = "yyyy-MM-dd";  
        }  
        SimpleDateFormat sdf = new SimpleDateFormat(fmtstr, Locale.UK);  
        return sdf.parse(datestr);  
    } catch (Exception e) {  
        return null;  
    }  
}  
/** 
 * 日期轉化為String 
 * @param date 
 * @return date string 
 */ 
private static String fmtDate(Date date) {  
    if (null == date) {  
        return null;  
    }  
    try {  
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US);  
        return sdf.format(date);  
    } catch (Exception e) {  
        return null;  
    }  
}  

/** 
 * 判斷是否存在某屬性的 set方法 
 * @param methods 
 * @param fieldSetMet 
 * @return boolean 
 */ 
private static boolean checkSetMet(Method[] methods, String fieldSetMet) {  
    for (Method met : methods) {  
        if (fieldSetMet.equals(met.getName())) {  
            return true;  
        }  
    }  
    return false;  
}  
/** 
 * 判斷是否存在某屬性的 get方法 
 * @param methods 
 * @param fieldGetMet 
 * @return boolean 
 */ 
private static boolean checkGetMet(Method[] methods, String fieldGetMet) {  
    for (Method met : methods) {  
        if (fieldGetMet.equals(met.getName())) {  
            return true;  
        }  
    }  
    return false;  
}  

/** 
 * 拼接某屬性的 get方法 
 * @param fieldName 
 * @return String 
 */ 
private static String parGetName(String fieldName) {  
    if (null == fieldName || "".equals(fieldName)) {  
        return null;  
    }  
    return "get" + fieldName.substring(0, 1).toUpperCase()  
            + fieldName.substring(1);  
}  
/** 
 * 拼接在某屬性的 set方法 
 * @param fieldName 
 * @return String 
 */ 
private static String parSetName(String fieldName) {  
    if (null == fieldName || "".equals(fieldName)) {  
        return null;  
    }  
    return "set" + fieldName.substring(0, 1).toUpperCase()  
            + fieldName.substring(1);  
} 
 

}