package com.cjonline.foundation.util;

import java.lang.reflect.Field;

import java.math.BigDecimal;

import java.text.SimpleDateFormat;

import java.util.Collection;

import java.util.Date;

public class JsonUtils {

/** 默认的字符串格式 */

private static String dateformat = "yyyy-MM-dd hh:mm:ss";

/**

* 获取日期字符串格式

*

* @return

*/

public static String getDateformat() {

return dateformat;

}

/**

* 设置日期字符串格式

*

* @param dateformat

*/

public void setDateformat(String dateformat) {

JsonUtils.dateformat = dateformat;

}

/**

* 获取实体bean的属性返回类型

*

* @param typeName

* 类型名称

* @param fieldValue

* 字段值

* @return

*/

private static Object toType(Object fieldValue) {

Object result = "";

if (fieldValue instanceof String) {

String value = (String) fieldValue;

if (value.contains("\r\n")) {

value = value.replaceAll("\r\n", "\\\\r\\\\n");

}

result = "\"" + value + "\"";

} else if (fieldValue instanceof Number) {

result = fieldValue;

} else if (fieldValue instanceof Boolean) {

result = fieldValue;

} else if (fieldValue instanceof BigDecimal) {

result = fieldValue;

} else if (fieldValue instanceof Date) {

SimpleDateFormat sdf = new SimpleDateFormat(getDateformat());

result = "\"" + sdf.format(fieldValue) + "\"";

} else {

result = "\"" + "\"";

;

}

return result;

}

/**

* 是将单个实体bean的格式化为json字符串

*

* @param obj

* 实体bean

* @return json字符串

* @throws IllegalAccessException

* @throws IllegalArgumentException

* @throws Exception

*/

public static String Object2JSON(Object obj, Object[] showfields) {

StringBuffer sb = new StringBuffer();

sb.append("{");

if (obj == null) {

return sb.append("}").toString();

}

Field[] fds = obj.getClass().getDeclaredFields();

for (int i = 0; i < fds.length; i++) {

fds[i].setAccessible(true);

String fieldName = fds[i].getName();

Object fieldValue = null;

try {

fieldValue = fds[i].get(obj);

} catch (Exception e) {

e.printStackTrace();

}

if (showfields == null) {

sb.append("\"" + fieldName + "\"").append(":");

sb.append(toType(fieldValue)).append(",");

} else {

for (Object showfield : showfields) {

if (showfield instanceof String) {

if (fieldName.equalsIgnoreCase((String) showfield)) {

sb.append("\"" + fieldName + "\"").append(":");

sb.append(toType(fieldValue)).append(",");

}

}

}

}

}

String result = "";

if (sb.toString().length() == 1) {

result = "{";

} else {

result = sb.substring(0, sb.length() - 1);

}

return result + "}";

}

/** * 可以对多个实体bean的集合操作，输出的是grid的格式 * * @param obj * 可以使实体bean的集合或个体 * @param showfields * 需要显示的字段 * @return * @throws Exception */ public static String ListObject2JSON(Object obj, Object[] showfields) throws Exception { StringBuffer sb = new StringBuffer(); StringBuffer rows = new StringBuffer(); sb.append("["); if (obj instanceof Collection) { @SuppressWarnings("rawtypes") Collection cc = (Collection) obj; if (cc.size() < 1) { return sb.append("]").toString(); } Object[] objects = cc.toArray(); for (Object object : objects) { rows.append(Object2JSON(object, showfields)).append(","); } rows = rows.replace(rows.length() - 1, rows.length(), ""); } sb.append(rows).append("]"); return sb.toString(); } }