一个可以即插即用的MD5加密签名方式

import java.util.*;


import org.apache.commons.codec.digest.DigestUtils;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.util.StringUtils;


public class Md5Sgin {

private static String authKey = "OOOOOOOOOXXXXXXXXXXX";


public static HashMap<String, Object> convertToMap(String msg) throws Exception {
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonNode = mapper.readTree(msg);
@SuppressWarnings("unchecked")
HashMap<String, Object> objMap = mapper.convertValue(jsonNode,
HashMap.class);
return objMap;
}


public static String generateSignatureByMsg(String jsonMsg) throws Exception{//生成签名
HashMap<String,Object> map=convertToMap(jsonMsg);
if(map.containsKey("sign")){
map.remove("sign");// 移除个人签名
}

map.put("authKey", authKey);
return generateSignature(map);
}

public static String generateSignature( Map<String,Object> parameters){
        StringBuilder str = new StringBuilder();
        List<String> sorted = new ArrayList<String>();
        for (Map.Entry<String, Object> entry : parameters.entrySet()) {
        if(entry.getValue()!=null){
        if (entry.getValue() instanceof List) {
Object[] objArr=((List)entry.getValue()).toArray();
LinkedHashMap<String, Object> tmpMap=null;
StringBuffer sBuffer=new StringBuffer();
sBuffer.append("[");
for (int i = 0; i < objArr.length; i++) {
tmpMap=(LinkedHashMap<String, Object>) objArr[i];
StringBuffer mapBuffer=new StringBuffer();
mapBuffer.append("{");
for (Map.Entry<String,Object> tmpEntry : tmpMap.entrySet()) {
if (tmpEntry.getValue()!=null)
mapBuffer.append(tmpEntry.getKey()+"="+tmpEntry.getValue().toString()+",");
}
if (mapBuffer.length()>1) {
mapBuffer.deleteCharAt(mapBuffer.length()-1);
}
mapBuffer.append("}");
if (i==objArr.length-1) {
sBuffer.append(mapBuffer.toString());
}else {
sBuffer.append(mapBuffer.toString()+",");
}
}
        sBuffer.append("]");
        sorted.add(entry.getKey()+ "=" +sBuffer.toString());
}else {
sorted.add(entry.getKey()+ "=" + entry.getValue().toString());
}
        }
}
        sorted.sort( (String p,String q) -> p.compareTo(q) );
        sorted.forEach(str::append);
        System.out.println(DigestUtils.md5Hex(str.toString()));
        return DigestUtils.md5Hex(str.toString());
    }
    

public static String generateSignatureByMsgForCheck(String jsonStr) throws Exception {//验证签名是否正确（该处只验证body{}）
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonNode = mapper.readTree(jsonStr);
@SuppressWarnings("unchecked")
HashMap<String, Object> objMap = mapper.convertValue(jsonNode,HashMap.class);
@SuppressWarnings("unchecked")
HashMap<String,Object> mapBody=(HashMap<String, Object>) objMap.get("body");
mapBody.remove("sign");
String verifySign=generateSignature(mapBody);
return verifySign;
}

// public static void  main(String [] s) {
// String beforesign = "{\"body\":\"youcai\",\"merchantId\":\"1\",\"notifyUrl\":\"http://vpca-*******elenet.me/mer******i-pay*****pi/pay******status\",\"orderTotalAmount\":\"10\",\"orderTradeNo\":\"15561512*********3117321774\",\"payDeadLine\":\"26\",\"returnUrl\":\"localhost%3A8080%2F%23%2Forder\",\"sign\":\"f21ca8*********b2e593\",\"source\":\"web\",\"spBillCreateIp\":\"8.8.8.8\"}";
// try {
// System.out.println(beforesign);
// String aftersign = generateSignatureByMsg(beforesign);
// System.out.println(aftersign);
// } catch (Exception e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }

}