PayCommonUtil

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.SAXException;

import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;
import java.util.Map.Entry;

/**
 * 工具类
 */
public class PayCommonUtil {

    private static Logger logger = LoggerFactory.getLogger(PayCommonUtil.class);

    /**
     * 自定义长度随机字符串
     * @param length
     * @return
     */
    public static String createConceStr(int length) {
        String strs = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        String str = "";
        for (int i = 0; i < length; i++) {
            // str +=strs.substring(0, new Random().nextInt(strs.length()));
            char achar = strs.charAt(new Random().nextInt(strs.length() - 1));
            str += achar;
        }
        return str;
    }


    /**
     * 获取时间戳
     * 时间戳从1970年1月1日00:00:00至今的秒数
     */
    public static long getTimeStamp() {
        Date d = new Date();
        long timeStamp = d.getTime() / 1000;     //getTime()得到的是微秒， 需要换算成秒
        return timeStamp;
    }


    /**
     * 默认16 位随机字符串
     * @return
     */
    public static String CreateNoncestr() {
        String chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        String res = "";
        for (int i = 0; i < 16; i++) {
            Random rd = new Random();
            res += chars.charAt(rd.nextInt(chars.length() - 1));
        }
        return res;
    }

    /**
     * 签名工具
     * @Description：sign签名
     * @param characterEncoding
     *            编码格式 UTF-8
     * @param parameters
     *            请求参数
     * @return
     */
    public static String createSign(String characterEncoding, Map parameters) {
        StringBuffer sb = new StringBuffer();

        //对参数按照key=value的格式，并按照参数名ASCII字典序排序如下：
        Map params = sortMap(parameters);

        Iterator> it = params.entrySet().iterator();
        while (it.hasNext()) {
            Entry entry = (Entry) it.next();
            String key = (String) entry.getKey();
            Object value = entry.getValue();//去掉带sign的项
            if (null != value && !"".equals(value) && !"sign".equals(key)
                && !"key".equals(key)) {
                sb.append(key + "=" + value + "&");
            }
        }
        sb.append("key=" + WXPayConstant.KEY);
        //注意sign转为大写
        return MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase();
    }

    /**
     * 对map根据key进行排序 ASCII 顺序
     *
     * @param map(无序的)
     * @return
     */
    public static Map sortMap(Map map) {

        List> infoIds = new ArrayList>(
            map.entrySet());
        Collections.sort(infoIds, new Comparator>() {
            public int compare(Entry o1,
                               Entry o2) {
                // return (o2.getValue() - o1.getValue());//value处理
                return (o1.getKey()).toString().compareTo(o2.getKey());
            }
        });
        Map sortmap = new TreeMap();
        for (int i = 0; i < infoIds.size(); i++) {
            String[] split = infoIds.get(i).toString().split("=");
            sortmap.put(split[0], split[1]);
        }
        return sortmap;
    }
    /**
     * @date
     * @Description：将请求参数转换为xml格式的string
     * @param parameters
     *            请求参数
     * @return
     */
    public static String getRequestXml(Map parameters) {
        StringBuffer sb = new StringBuffer();
        sb.append("");
        Iterator> iterator = parameters.entrySet().iterator();
        while (iterator.hasNext()) {
            Entry entry = (Entry) iterator.next();
            String key = (String) entry.getKey();
            String value = (String) entry.getValue().toString();
            sb.append("<" + key + ">" + value + "");
        }
        sb.append("");
        return sb.toString();
    }

    public static String setXML(String return_code, String return_msg) {
        return "";
    }


    /**
     * 检验API返回的数据里面的签名是否合法
     *
     * @param responseString API返回的XML数据字符串
     * @return API签名是否合法
     * @throws ParserConfigurationException
     * @throws IOException
     * @throws SAXException
     */
    public static boolean checkIsSignValidFromResponseString(String responseString) {

        try {
            Map map = doXMLParse(responseString);
            logger.debug(map.toString());
            String signFromAPIResponse = map.get("sign").toString();
            if ("".equals(signFromAPIResponse) || signFromAPIResponse == null) {
                logger.debug("API返回的数据签名数据不存在，有可能被第三方篡改!!!");
                return false;
            }
            logger.debug("服务器回包里面的签名是:" + signFromAPIResponse);
            map.put("sign", "");
            String signForAPIResponse = PayCommonUtil.createSign("UTF-8", map);
            if (!signForAPIResponse.equals(signFromAPIResponse)) {
                logger.debug("数据签名验证不通过");
                return false;
            }
            logger.debug("恭喜，数据签名验证通过!!!");
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * 解析xml,返回第一级元素键值对。
     * 如果第一级元素有子节点，
     * 则此节点的值是子节点的xml数据。
     *
     * @param strxml
     * @return
     * @throws JDOMException
     * @throws IOException
     */
    public static Map doXMLParse(String strxml)
        throws JDOMException, IOException {
        strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");
        if (null == strxml || "".equals(strxml)) {
            return null;
        }
        Map map = new TreeMap();
        InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8"));
        SAXBuilder builder = new SAXBuilder();
        Document doc = builder.build(in);
        Element root = doc.getRootElement();
        List list = root.getChildren();
        Iterator it = list.iterator();
        while (it.hasNext()) {
            Element e = (Element) it.next();
            String key = e.getName();
            String value = "";
            List children = e.getChildren();
            if (children.isEmpty()) {
                value = e.getTextNormalize();
            } else {
                value = getChildrenText(children);
            }
            map.put(key, value);
        }
        // 关闭流
        in.close();
        return map;
    }

    /**
     * 获取子结点的xml
     * @param children
     * @return
     */
    public static String getChildrenText(List children) {
        StringBuffer sb = new StringBuffer();
        if (!children.isEmpty()) {
            Iterator it = children.iterator();
            while (it.hasNext()) {
                Element e = (Element) it.next();
                String name = e.getName();
                String value = e.getTextNormalize();
                List list = e.getChildren();
                sb.append("<" + name + ">");
                if (!list.isEmpty()) {
                    sb.append(getChildrenText(list));
                }
                sb.append(value);
                sb.append("");
            }
        }
        return sb.toString();
    }
}