RequestBodyAdvice-和-ResponseBodyAdvice-全局处理输入输出

使用场景

1. 需要对项目中的所有输入进行前后空格的过滤
2. 替换一些特殊字符的输入
3. 解密一些关键性字段
4. 注入一些参数在请求方法的时候
5. 返回参数统一处理，如果后台返回空，统一返回成功信息
6. 身份证等特殊字符统一做 * 号处理等

code

主要就是用到了 RequestBodyAdvice 和 ResponseBodyAdvice 两个接口和一个注解
@ControllerAdvice

• 请求参数去空格

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;

/**
 * 去掉前后空格和特殊字符
 */
@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();

            // 空参，get 请求，流为空，非 application/json 请求，不处理参数
            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;}

            // 正式过滤 json 参数
            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("参数不支持去空格:" + 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 处理返回空返回

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;

/**
 * 可以定义空返回的时候返回正确的信息，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}");
    }
}

项目代码

我弄了一个例子代码，关于 java 中每个工具的使用，如 rabbitmq，mysql，mybatis，springboot，springmvc 可以方便初学者，更方便我自己随时取用，github 地址
https://gitee.com/sanri/example

sanri-tools 工具

推广下我的小工具，很实用的解决项目中的一些麻烦的事情，欢迎来 github 点星，fork
https://gitee.com/sanri/sanri-tools-maven