反编译 java

1.winrar

https://www.rarlab.com/

2.github  jd-gui

http://java-decompiler.github.io/

SignNatureTest.java

package com.gatewayrmb;

import java.util.*;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.lang3.StringUtils;
import java.text.SimpleDateFormat;
import java.util.Date;
public class SignNatureTest{
    public static String createSign(Map<String, String> params, String privateKey) {
        StringBuilder sb = new StringBuilder();
        //韩
        Map<String, String> sortParams = new TreeMap<String, String>(params);

        for (Map.Entry<String, String> entry : sortParams.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue().trim();
            if (StringUtils.isNotEmpty(value))
                sb.append("&").append(key).append("=").append(value);
        }
        System.out.print(sb);
        String stringA = sb.toString().replaceFirst("&", "");
        String stringSignTemp = stringA + privateKey;
        return  DigestUtils.md5Hex(stringSignTemp);

    }

    public static String getTimestamp(){
        // int to str
        int s=2;
        String b=Integer.toString(s);
        // String.valueOf(o)
        return String.valueOf(System.currentTimeMillis());
    }

    public static String  testTime(){

        SimpleDateFormat  formats = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String stamp= formats.format(new Date());
        System.out.print(stamp);
        return  String.valueOf(stamp);
    }
    public static void main(String[] args){
        HashMap<String, String> map=new HashMap<>();
        map.put("k1","values1");
        map.put("k2","33");
        String mykey="salt";
        System.out.print("\nMD5string is: "+createSign(map,mykey));
        testTime();
//        System.out.print("i am replace class");

    }
}

　　

//dependency
  <dependencies>
    <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
      <version>3.9</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.directory.studio/org.apache.commons.codec -->
    <dependency>
      <groupId>org.apache.directory.studio</groupId>
      <artifactId>org.apache.commons.codec</artifactId>
      <version>1.3</version>
    </dependency>