文件下载出现 IOExpcetion: closed

异常原因截图 :

异常代码位置 :

出现的原因是  使用 try-with-resources,  downloadFile 方法执行完毕, 文件流被关闭了...导致前面读取文件字节, 异常提示已经关闭...

try (Response response = OkHttpUtils.getInstance().client.newCall(new Request.Builder().url(fileUrl).build()).execute()) {

正确的写法是 : 

不使用 try-with-resources, 使用常规写法, 所以说 try-with-resources 这个语法虽然方便, 但使用起来也要注意代码上下文

    /**
     * 根据资源网络url下载文件
     *
     * @param fileUrl
     * @return
     */
    public static InputStream downloadFile(String fileUrl) {
        try {
            Response response = OkHttpUtils.getInstance().client.newCall(new Request.Builder().url(fileUrl).build()).execute();
            Assert.notNull(response, "http request error");
            Assert.isTrue(response.isSuccessful(), "http request not successful");
            ResponseBody body = response.body();
            Assert.notNull(body, "http request error");
            return body.byteStream();
        } catch (Exception e) {
            log.error("http download file error, ", e);
            throw new RuntimeException("http error.");
        }
    }

附上 OkHttpUtils 工具类, 单例实现的

package com.ckx.pricing.third.common.util;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import okhttp3.*;
import org.springframework.util.Assert;

import java.io.InputStream;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;

/**
 * @author yukun.yan
 * @description OkHttpUtils
 * @date 2023/5/29 11:38
 */
@Slf4j
public class OkHttpUtils {

    private final OkHttpClient client;

    private static final ObjectMapper objectMapper = new ObjectMapper();

    public OkHttpUtils() {
        client = new OkHttpClient.Builder()
                .protocols(Arrays.asList(Protocol.HTTP_2, Protocol.HTTP_1_1))
                .connectTimeout(60, TimeUnit.SECONDS)
                .readTimeout(60, TimeUnit.SECONDS)
                .writeTimeout(60, TimeUnit.SECONDS)
                .connectionPool(new ConnectionPool(10, 20, TimeUnit.MINUTES))
                .build();
    }

    /**
     * 执行一个http请求, 返回 响应数据
     *
     * @param request
     * @return
     */
    public static String newCall(Request request) {
        if (request == null) {
            throw new IllegalArgumentException("Request cannot be null");
        }
        try (Response response = OkHttpUtils.getInstance().client.newCall(request).execute()) {
            Assert.notNull(response, "http request error");
            Assert.isTrue(response.isSuccessful(), "http request not successful");
            ResponseBody body = response.body();
            Assert.notNull(body, "http request error");
            return body.string();
        } catch (Exception e) {
            throw new RuntimeException("http error.");
        }
    }

    /**
     * 入参解析为请求入参
     *
     * @param object
     * @param <T>
     * @return
     */
    public static <T> RequestBody toPostRequestBody(T object) {
        ObjectMapper objectMapper = new ObjectMapper();
        String jsonRequestBody = null;
        try {
            jsonRequestBody = objectMapper.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            log.error("request json error, ", e);
        }
        Assert.notNull(jsonRequestBody, "request not be null");
        MediaType JSON = MediaType.get("application/json; charset=utf-8");
        return RequestBody.create(JSON, jsonRequestBody);
    }

    /**
     * 对网络请求返回值解析, 解密标椎json格式
     *
     * @param jsonResp
     * @param tClass
     * @param <T>
     * @return
     */
    public static <T> T readResponseValue(String jsonResp, Class<T> tClass) {
        try {
            return objectMapper.readValue(jsonResp, tClass);
        } catch (JsonProcessingException e) {
            throw new RuntimeException("response to json error");
        }
    }

    /**
     * 根据资源网络url下载文件
     *
     * @param fileUrl
     * @return
     */
    public static InputStream downloadFile(String fileUrl) {
        try {
            Response response = OkHttpUtils.getInstance().client.newCall(new Request.Builder().url(fileUrl).build()).execute();
            Assert.notNull(response, "http request error");
            Assert.isTrue(response.isSuccessful(), "http request not successful");
            ResponseBody body = response.body();
            Assert.notNull(body, "http request error");
            return body.byteStream();
        } catch (Exception e) {
            log.error("http download file error, ", e);
            throw new RuntimeException("http error.");
        }
    }

    private static class OkHttpUtilsInstanceOwner {

        private static final OkHttpUtils INSTANCE = new OkHttpUtils();

    }

    /**
     * 返回该类的单例对象, 并自动初始化构造器
     *
     * @return
     */
    public static OkHttpUtils getInstance() {
        return OkHttpUtilsInstanceOwner.INSTANCE;
    }

}