Java Awesome

反编译/解密
加密/混淆
- core-lib/xjar
  - Apache-2.0, Java
- roseboy/classfinal
  - Apache-2.0, Java
  - Java Class Encryption Tool
  - 基于 -agentJava
    .jar
  - 原始的class文件并不会完全被加密，只是方法体被清空，保留方法参数、注解等信息，这是为了兼容spring，swagger等扫描注解的框架；方法体被清空后，反编译者只能看到方法名和注解，看不到方法的具体内容；当class被classloader加载时，真正的方法体会被解密注入。
  - gitee
  - java -javaagent:yourpaoject-encrypted.jar='-pwd 0000000' -jar yourpaoject-encrypted.jar
  - 为了保证项目在运行时的安全，启动jvm时请加参数: -XX:+DisableAttachMechanism
  - roseboy/classfinal/classfinal-core/src/main/java/net/roseboy/classfinal/JarDecryptor.java
  - 默认密码 org.springframework.config.Pass
  - 机器码 org.springframework.config.Code
  - 密码的 Hash org.springframework.config.PassHash
  - META-INF/.classes/
  - net.roseboy.classfinal.CoreAgent

java

import net.roseboy.classfinal.JarDecryptor;
import net.roseboy.classfinal.util.EncryptUtils;
import net.roseboy.classfinal.util.StrUtils;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

public class DecryptClassFinal {
    public static void main(String[] args) throws IOException {
        String src =System.getProperty("user.dir") +  "/tmp/META-INF/.classes";
        String dst = System.getProperty("user.dir") + "/src/main/class";


        File srcDir = new File(src);
        JarDecryptor.getInstance();
        String pass = Files.readString(Path.of(src+"/org.springframework.config.Pass"));
        char[] password =  EncryptUtils.md5(pass.toCharArray());

        System.out.printf("src:%s\n", src);
        System.out.printf("dst:%s\n", dst);
        System.out.printf("password:%s\n", pass);

        if (srcDir.isDirectory()) {
            for (File file : srcDir.listFiles()) {
                String fp = file.getName();
                if (fp.startsWith("org.springframework")) {
                    continue;
                }

                byte[] fileBytes = Files.readAllBytes(file.toPath());
                byte[] out = dec(password, fp, fileBytes);

                String[] split = fp.split("[.]");
                String fn = split[split.length-1];

                String p = dst+"/"+ fp.substring(0, fp.lastIndexOf('.')).replaceAll("[.]", "/");
                new File(p).mkdirs();
                String f = p+"/"+ fn +".class";

                System.out.println("Write to: "+f+" Len:"+out.length);
                Files.write(new File(f).toPath(), out);
            }
        }

    }

    public static byte[] dec(char[] password, String fileName, byte[] bytes){
        char[] pass;
        pass = StrUtils.merger(new char[][]{password, fileName.toCharArray()});
        return  EncryptUtils.de(bytes, pass, 1);
    }
}

bash

java -cp ~/Applications/IntelliJ\ IDEA\ Ultimate.app/Contents/plugins/java-decompiler/lib/java-decompiler.jar \
  org.jetbrains.java.decompiler.main.decompiler.ConsoleDecompiler \
  -dgs=true \
  src/main/class/ src/main/java/

JDK

如何选择 JDK 和版本？

用 Adoptium
只用 LTS 版本

发行版
- Adoptium
  - AdoptOpenJDK -> Adoptium
  - Eclipse 维护
  - Eclipse Temurin - name of the OpenJDK distribution from Adoptium
- Amazon Corretto
- Alibaba Dragonwell
- GraalVM
- Java.net
- Zulu
- Liberica
- Liberica NIK
- Microsoft
- Oracle
- Mandrel
- SapMachine
- Semeru
- Trava
JVM 实现
- Hotpot
- OpenJ9
- GraalVM
- SubstrateVM
  - GraalVM Native
whichjdk
- www.pentalog.com/blog/it-development-technology/java-versions-distributions-platforms
Version Manager

Languages

效率

lombok

Frameworks

spring
microprofile
quakus
OpenLiberty/open-liberty
- IBM
oracle/helidon
- microservices
micronaut
vertx
Sprint Cloud Vendor
- Sprint Cloud Alibaba
- Sprint Cloud GCP
- Sprint Cloud Netflix
- Sprint Cloud AWS
- Sprint Cloud Azure
- Sprint Cloud Huawei
国产
- nutzam/nutz