RequestBodyAdvice 和 ResponseBodyAdvice 全局處理輸入輸出

使用場景

1. 需要對項目中的所有輸入進行前後空格的過濾
2. 替換一些特殊字符的輸入
3. 解密一些關鍵性字段
4. 注入一些參數在請求方法的時候
5. 返回參數統一處理，如果後臺返回空，統一返回成功信息
6. 身份證等特殊字符統一做 * 號處理等

code

主要就是用到了 RequestBodyAdvice 和 ResponseBodyAdvice 兩個接口和一個註解
@ControllerAdvice

• 請求參數去空格

package com.sanri.test.testmvc.config;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.util.Iterator;
import java.util.Map;

/**
 * 去掉前後空格和特殊字符
 */
@Slf4j
@ControllerAdvice
public class CustomRequestBodyAdvice implements RequestBodyAdvice {
    @Override
    public boolean supports(MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
        return true;
    }

    @Override
    public Object handleEmptyBody(Object body, HttpInputMessage httpInputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
        return body;
    }

    @Override
    public HttpInputMessage beforeBodyRead(HttpInputMessage httpInputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) throws IOException {
        return new CustomHttpInputMessage(httpInputMessage);
    }

    @Override
    public Object afterBodyRead(Object body, HttpInputMessage httpInputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
        return body;
    }

    class CustomHttpInputMessage implements HttpInputMessage{
        private HttpInputMessage origin;

        public CustomHttpInputMessage(HttpInputMessage httpInputMessage) {
            this.origin = httpInputMessage;
        }

        @Override
        public InputStream getBody() throws IOException {
            HttpHeaders headers = origin.getHeaders();
            InputStream body = origin.getBody();

            // 空參，get 請求，流爲空，非 application/json 請求，不處理參數
            MediaType contentType = headers.getContentType();
            if(contentType == null){return body;}
            if(!contentType.isCompatibleWith(MediaType.APPLICATION_JSON)){return body;}
            if(body == null){return body;}
            String params = IOUtils.toString(body, "utf-8");
            if(StringUtils.isBlank(params)){return body;}

            // 正式過濾 json 參數
            Object parse = JSON.parse(params);
            if (parse instanceof JSONArray) {
                JSONArray jsonArray = (JSONArray) parse;
                trimJsonArray(jsonArray);
            } else if (parse instanceof JSONObject) {
                trimJsonObject((JSONObject) parse);
            } else {
                log.error("參數不支持去空格:" + parse+ " contentType:"+contentType);
            }
            return IOUtils.toInputStream(JSON.toJSONString(parse, SerializerFeature.WriteMapNullValue), "UTF-8");
        }

        private void trimJsonObject(JSONObject jsonObject) {
            Iterator<Map.Entry<String, Object>> iterator = jsonObject.entrySet().iterator();
            while (iterator.hasNext()) {
                Map.Entry<String, Object> next = iterator.next();
                String key = next.getKey();
                Object value = next.getValue();
                if (value instanceof JSONArray) {
                    trimJsonArray((JSONArray) value);
                }else if(value instanceof JSONObject){
                    trimJsonObject((JSONObject) value);
                }else if(value instanceof  String){
                    String trimValue = StringUtils.trim(ObjectUtils.toString(value));
                    next.setValue(filterDangerString(trimValue));
                }
            }
        }

        private void trimJsonArray(JSONArray jsonArray) {
            for (int i = 0; i < jsonArray.size(); i++) {
                Object object = jsonArray.get(i);
                if(object instanceof JSONObject){
                    JSONObject jsonObject = jsonArray.getJSONObject(i);
                    trimJsonObject(jsonObject);
                }else if(object instanceof  String){
                    String trimValue = StringUtils.trim(ObjectUtils.toString(object));
                    jsonArray.set(i,trimValue);
                }

            }
        }

        @Override
        public HttpHeaders getHeaders() {
            return origin.getHeaders();
        }

        private String filterDangerString(String value) {
            if(StringUtils.isBlank(value))return value;

            value = value.replaceAll(";", "；");
            value = value.replaceAll("'", "‘");
            value = value.replaceAll("<", "《");
            value = value.replaceAll(">", "》");
            value = value.replaceAll("\\(", "（");
            value = value.replaceAll("\\)", "）");
            value = value.replaceAll("\\?", "？");
            return value;
        }

    }
}

• 使用 ResponseBodyAdvice 處理返回空返回

package com.sanri.test.testmvc.config;

import com.alibaba.fastjson.JSONObject;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import java.lang.reflect.AnnotatedType;
import java.lang.reflect.Executable;
import java.lang.reflect.Type;

/**
 * 可以定義空返回的時候返回正確的信息，如成功信息
 */
@RestControllerAdvice
public class CustomResponseBodyAdvice implements ResponseBodyAdvice {
    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        Executable executable = returnType.getExecutable();
        AnnotatedType annotatedReturnType = executable.getAnnotatedReturnType();
        Type type = annotatedReturnType.getType();
        return JSONObject.parseObject("{\"result\":0}");
    }
}

項目代碼

我弄了一個例子代碼，關於 java 中每個工具的使用，如 rabbitmq，mysql，mybatis，springboot，springmvc 可以方便初學者，更方便我自己隨時取用，github 地址
https://gitee.com/sanri/example

sanri-tools 工具

推廣下我的小工具，很實用的解決項目中的一些麻煩的事情，歡迎來 github 點星，fork
https://gitee.com/sanri/sanri-tools-maven