java中对TreeMap排序字符串问题

/**小弟也是从PHPer转过来的,目前实习java一些方法修改，这次改动是对treemap进行排序 url拼接,**/

敲定了,java先放一放，让我配合写后端同步验证

java生成sign,后端验证sign

生成

Object localObject1 = new TreeMap();
    ((TreeMap)localObject1).put("cartoonId", paramString1);
    final Object localObject2 = new StringBuilder();
    ((StringBuilder)localObject2).append(paramLong);
    ((StringBuilder)localObject2).append("");
    ((TreeMap)localObject1).put("chapterId", ((StringBuilder)localObject2).toString());
    ((TreeMap)localObject1).put("token", NewConstants.BASETOKEN());
    ((TreeMap)localObject1).put("timestamp", paramString2);
    ((TreeMap)localObject1).put("mark", "hahaha");
    Object localObject3 = SignUtil.md5(SignUtil.getParamLink((TreeMap)localObject1));

localObject3(sign字段)方法

package com.jj.comics.util;

import android.text.TextUtils;
import android.util.Base64;
import androidx.annotation.NonNull;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Set;
import java.util.TreeMap;

public class SignUtil
{
  public static String getParamLink(TreeMap<String, String> paramTreeMap)
  {
    StringBuilder localStringBuilder = new StringBuilder();
    paramTreeMap = paramTreeMap.entrySet().iterator();
    while (paramTreeMap.hasNext())
    {
      Map.Entry localEntry = (Map.Entry)paramTreeMap.next();
      if ((localEntry.getValue() != null) && (((String)localEntry.getValue()).length() > 0))
      {
        localStringBuilder.append((String)localEntry.getKey());
        localStringBuilder.append("=");
        localStringBuilder.append((String)localEntry.getValue());
        localStringBuilder.append("&");
      }
    }
    if (localStringBuilder.length() > 0) {
      localStringBuilder.deleteCharAt(localStringBuilder.length() - 1);
    }
    return localStringBuilder.toString();
  }
  
  @NonNull
  public static String md5(String paramString)
  {
    if (TextUtils.isEmpty(paramString)) {
      return "";
    }
    try
    {
      byte[] arrayOfByte = MessageDigest.getInstance("MD5").digest(paramString.getBytes());
      StringBuilder localStringBuilder = new java/lang/StringBuilder;
      localStringBuilder.<init>();
      int i = arrayOfByte.length;
      for (int j = 0; j < i; j++)
      {
        String str = Integer.toHexString(arrayOfByte[j] & 0xFF);
        paramString = str;
        if (str.length() == 1)
        {
          paramString = new java/lang/StringBuilder;
          paramString.<init>();
          paramString.append("0");
          paramString.append(str);
          paramString = paramString.toString();
        }
        localStringBuilder.append(paramString);
      }
      paramString = localStringBuilder.toString();
      return paramString;
    }
    catch (NoSuchAlgorithmException paramString)
    {
      paramString.printStackTrace();
    }
    return "";
  }
  
  public static String sign(String paramString)
  {
    return md5(Base64.encodeToString(paramString.getBytes(), 2)).substring(8, 24);
  }
}

然后传递数据

cartoonId chapterId token timestamp  sign=localObject3  （mark是规定 前后端一致）

我后端拿到这些数据后,应该如何验证sign是否合法

主要是后端进行 = &拼接排序 还有他的md5方法是不是和php的md5不一样啊

默认应该是put的顺序，排序要自己从新处理的。