判断一个对象的值是否为空、根据column获取想对应的数据库字段

 

public class ClazUtil {
	
	private static Logger logger = LoggerFactory.getLogger(ClazUtil.class);

    public static String verifyDTO(Object o,String[] names) {
    	if(o == null){
    		String msg = "接口参数data不能为空！";
    		logger.error(msg);
    		return msg;
    	}
    	
    	if(names == null || names.length == 0){
    		String msg = "名字不能为空！";
    		logger.error(msg);
    		return "";
    	}
    	
    	StringBuffer error = new StringBuffer();
    	Object[] values = ClazUtil.getFiledValues(o);
    	String[] types = ClazUtil.getFiledTypes(o);
    	
    	if(values.length != names.length) {
    		logger.error("名字和属性个数不匹配！");
    		return "";
    	}
    	
    	for(int i = 0;i < values.length;i++){
    		Object value = values[i];
    		String type = types[i];
    		String name = names[i];
    		try {
				Class<?> typeClaz = Class.forName(type);
				if(typeClaz == String.class){
					if(StringUtils.isEmpty(String.valueOf(value)) || value == null) error.append(name).append("为空!\n");
				}else{
					if(value == null) error.append(name).append("不能为空!\n");
				}
			} catch (ClassNotFoundException e) {
				logger.error(e.getMessage());
				continue;
			}
    	}
    	return error.toString();
    }
    
    /**
     * 获取对象的所有属性值，返回一个对象数组
     */
    public static Object[] getFiledValues(Object o) {
    	Field[] fields = o.getClass().getDeclaredFields();
    	
        Object[] value = new Object[fields.length];
        for (int i = 0; i < fields.length; i++) {
        	Object mValue = null;
        	try {
        		String filedName = fields[i].getName();
	        	String firstLetter = filedName.substring(0, 1).toUpperCase();
	            String getter = "get" + firstLetter + filedName.substring(1);
	            Method method = o.getClass().getMethod(getter, new Class[] {});
	            mValue = method.invoke(o, new Object[] {});
        	} catch (Exception e) {
            	logger.error(e.getMessage(), e);
            }
            value[i] = mValue;
        }
        return value;
    }
    
    /**
     * <p>date: 2015年8月13日 上午10:06:03</p>
     * <p>description: 获取对象的所有类型 </p>
     * @author muzi131313
     * @param
     * @return
     */
    public static String[] getFiledTypes(Object o){
    	Field[] fields = o.getClass().getDeclaredFields();
        String[] fieldTypes = new String[fields.length];
        for (int i = 0; i < fields.length; i++) {
        	String type = fields[i].getType().toString();
        	if(type.contains("class ")) type = type.replaceAll("class ", "");
            fieldTypes[i] = type;
        }
        return fieldTypes;
    }
    
    
	/**
	 * <p>date: 2015年6月24日 下午12:18:09</p>
	 * <p>description: 获取实例变量名称和@column注解中name </p>
	 * @author muzi131313
	 * @param 带有@Column注解的pojo的类
	 * @return Map<filedName,columnName>
	 */
    public static Map<String,String> getFiledNameAndColumnName(Class<?> claz) {
        Field[] fields = claz.getDeclaredFields();
        Map<String,String> map = new HashMap<String,String>();
        for (int i = 0; i < fields.length; i++) {
        	Field field = fields[i];
        	String fieldName = field.getName();
        	
        	Annotation[] as = field.getAnnotations();
        	for(Annotation a : as){
        		Class<?> type = a.annotationType();
        		if(type == javax.persistence.Column.class){
        			try {
        				javax.persistence.Column c = (javax.persistence.Column)a;
        				String columnName = c.name();
        				if(StringUtils.isEmpty(columnName)){
        					columnName = fieldName;
        				}
        				map.put(fieldName, columnName);
					} catch (Exception e) {
						e.printStackTrace();
					}
        		}
        	}
        }
        return map;
    }
    
    public static void main(String[] args) {
    	
	}

	
}