MONGODB（四）——DBObject与JavaBean转换

一、DBObject 转为 JavaBean

   /**
     * 将实体Bean对象转换成DBObject
     *
     */
    public static <T> DBObject beanToDBObject(T bean)
            throws IllegalArgumentException, IllegalAccessException {
        if (bean == null)
            return null;
        DBObject dbObject = new BasicDBObject();
        // 获取对象类的属性域
        Field[] fields = bean.getClass().getDeclaredFields();
        for (Field field : fields) {
            // 获取变量的属性名
            String varName = field.getName();
            // 修改访问控制权限
            boolean accessFlag = field.isAccessible();
            if (!accessFlag) {
                field.setAccessible(true);
            }
            Object param = field.get(bean);
            if (param == null) {
                continue;
            } else if (param instanceof Integer) {
                // 判断变量的类型
                int value = ((Integer) param).intValue();
                dbObject.put(varName, value);
            } else if (param instanceof String) {
                String value = (String) param;
                dbObject.put(varName, value);
            } else if (param instanceof Double) {
                double value = ((Double) param).doubleValue();
                dbObject.put(varName, value);
            } else if (param instanceof Float) {
                float value = ((Float) param).floatValue();
                dbObject.put(varName, value);
            } else if (param instanceof Long) {
                long value = ((Long) param).longValue();
                dbObject.put(varName, value);
            } else if (param instanceof Boolean) {
                boolean value = ((Boolean) param).booleanValue();
                dbObject.put(varName, value);
            } else if (param instanceof Date) {
                Date value = (Date) param;
                dbObject.put(varName, value);
            }
            // 恢复访问控制权限
            field.setAccessible(accessFlag);
        }
        return dbObject;
    }

二、 JavaBean转为DBObject

      /**
     * 将DBObject转换成Bean对象
     *
     */
    public static <T> T dbObjectToBean(DBObject dbObject, T bean)
            throws IllegalAccessException, InvocationTargetException,
            NoSuchMethodException {
        if (bean == null) {
            return null;
        }
        Field[] fields = bean.getClass().getDeclaredFields();
        for (Field field : fields) {
            String varName = field.getName();
            Object object = dbObject.get(varName);
            if (object != null) {
                BeanUtils.setProperty(bean, varName, object);
            }

        }
        return bean;
    }

    // 取出Mongo中的属性值，为bean赋值
    public static <T> void setProperty(T bean, String varName, T object) {
        varName = varName.substring(0, 1).toUpperCase() + varName.substring(1);
        try {
            String type = object.getClass().getName();
            // 类型为String
            if (type.equals("java.lang.String")) {
                Method m = bean.getClass().getMethod("get" + varName);
                String value = (String) m.invoke(bean);
                if (value == null) {
                    m = bean.getClass()
                            .getMethod("set" + varName, String.class);
                    m.invoke(bean, object);
                }
            }
            // 类型为Integer
            if (type.equals("java.lang.Integer")) {
                Method m = bean.getClass().getMethod("get" + varName);
                String value = (String) m.invoke(bean);
                if (value == null) {
                    m = bean.getClass().getMethod("set" + varName,
                            Integer.class);
                    m.invoke(bean, object);
                }
            }
            // 类型为Boolean
            if (type.equals("java.lang.Boolean")) {
                Method m = bean.getClass().getMethod("get" + varName);
                String value = (String) m.invoke(bean);
                if (value == null) {
                    m = bean.getClass().getMethod("set" + varName,
                            Boolean.class);
                    m.invoke(bean, object);
                }
            }
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }