Springboot框架，实现请求数据解密，响应数据加密的功能。

一、简要说明：

　　在做这个功能的时候，参考了很多文章，也试了用过滤器解决。但总体来说还是很麻烦，所以换了另一种解决方案。直接实现RequestBodyAdvice和ResponseBodyAdvice两个接口 ，进行加密解密处理。

　　关于RequestBodyAdvice和ResponseBodyAdvice接口的作用，可参考该文档：

　 (1)https://blog.csdn.net/qq_16504067/article/details/73225005  

　 (2) https://blog.csdn.net/jing956899449/article/details/54315048

二、解密 DecodeRequestBodyAdvice

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.Type;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;
import lombok.extern.slf4j.Slf4j;

@Component
@ControllerAdvice(basePackages = "com.kiki.controller")
@Slf4j
public class DecodeRequestBodyAdvice implements RequestBodyAdvice {

    @Override
    public boolean supports(MethodParameter methodParameter, Type targetType,
            Class<? extends HttpMessageConverter<?>> converterType) {
        //这里设置成false 它就不会再走这个类了
        return true;
    }
    @Override
    public HttpInputMessage beforeBodyRead(HttpInputMessage request, MethodParameter parameter, Type targetType,
            Class<? extends HttpMessageConverter<?>> converterType) throws IOException {
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;
        try {
            //这个request其实就是入参 可以从这里获取流
            //入参放在HttpInputMessage里面  这个方法的返回值也是HttpInputMessage
            InputStream inputStream = request.getBody();
            if (inputStream != null) {
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                char[] charBuffer = new char[128];
                int bytesRead = -1;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } else {
                stringBuilder.append("");
            }
        } catch (IOException ex) {
            throw ex;
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    throw ex;
                }
            }
        }
        //获取请求数据
        String string = stringBuilder.toString();
        /*****************进行解密start*******************/
        log.info("【接受的请求数据】string={}",string);

        String decode =Base64Utils.decode(string);
        log.info("【解密后的请求数据】decode={}",decode);

        //把数据放到我们封装的对象中
        return new MyHttpInputMessage(request.getHeaders(), new ByteArrayInputStream(decode.getBytes("UTF-8")));
    }

    @Override
    public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
            Class<? extends HttpMessageConverter<?>> converterType) {
        return body;
    }

    @Override
    public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
            Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
        return body;
    }
    //这里实现了HttpInputMessage 封装一个自己的HttpInputMessage
    static class MyHttpInputMessage implements HttpInputMessage {
        HttpHeaders headers;
        InputStream body;

        public MyHttpInputMessage(HttpHeaders headers, InputStream body) {
            this.headers = headers;
            this.body = body;
        }

        @Override
        public InputStream getBody() throws IOException {
            return body;
        }

        @Override
        public HttpHeaders getHeaders() {
            return headers;
        }
    }

}

三、加密 EncodeResponseBodyAdvice 

import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;

@Component
@ControllerAdvice(basePackages = "com.kiki.controller")
@Slf4j
public class EncodeResponseBodyAdvice implements ResponseBodyAdvice<Object> {

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
            Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
                    ServerHttpResponse response) {
        System.out.println("response-------->"+body);
        //加密
        log.info("【接受到的数据】encode={}",body);
        String encode = Base64Utils.encode(JSON.toJSONString(body));
        return encode;
    }

}

四、工具类

import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class Base64Utils {
    /**
     * 使用Base64加密字符串
     * @return 加密之后的字符串
     * 
     */
    public static String encode(String data){
        return  Base64.getEncoder().encodeToString(data.getBytes(StandardCharsets.UTF_8));
    }
    /**
     * 使用Base64解密
     * @return 解密之后的字符串
     * 
     */
    public static String decode(String data){
        return new String(Base64.getDecoder().decode(data.replace("\"", "")),StandardCharsets.UTF_8);
    }
    public static void main(String[] args) {
        String encode = encode("{\"key\":\"kiki123\",\"value\":\"hello lmbx\"}");
        System.out.println(encode);
        String decode = decode("eyJrZXkiOiIxMjMiLCJ2YWx1ZSI6ImFhYSJ9");
        System.out.println(decode);
        
    }
}

五、bean

import lombok.Data;

@Data
public class DataBean {
    private String key;
    private String value;
}

六、Controller

import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.kiki.bean.DataBean;
@RestController
@RequestMapping("/api/")
public class DataController {
    @PostMapping("test")
    public DataBean test(@RequestBody DataBean dataBean) {
        System.out.println("controller::::"+dataBean);
        dataBean.setKey("456");
        dataBean.setValue("0000");
        return dataBean;
    }
}