8.14Java之使用HttpClient类通过POST方式上传文件

背景

简介：
因为在实际的业务当中存在上传文件的场景。经常是通过ajax发送form-data形式的表单。所以在测试的时候需要构造表单的形式进行测试。
关键参数

Content-Type:multipart/form-data;
参数：file二进制类型
构造实例：

package AmazonListingAPI;

import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.CookieStore;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.cookie.BasicClientCookie;
import org.apache.http.util.EntityUtils;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;

/**
 * 测试Amazon上传图片的API
 * @since JDK 1.8
 * @date 2021/08/14
 * @author Lucifer
 */
public class UploadFileAPITestNo2 {
    //设置文件路径
    private static File filePath = new File("C:\\Users\\Administrator\\Desktop\\Test_Work\\Test_Picture\\King.jpg");
    public static void uploadFile(String url, String cookValue){
        //设置Cookie
        CookieStore cookieStore = new BasicCookieStore();
        BasicClientCookie cookie = new BasicClientCookie("Cookie", cookValue);
        try {
            cookie.setDomain(new URL(url).getHost());
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        cookie.setPath("/");
        cookieStore.addCookie(cookie);
        CloseableHttpClient httpClient = HttpClients.custom().setDefaultCookieStore(cookieStore).build();

        String result = "";
        //每个post参数之间的分隔。随意设定，只要不会和其他的字符串重复即可。
        String boundary ="----WebKitFormBoundary0j3qBlYRoC96tFB3";
        try {
            //文件名
            String fileName = filePath.getName();
            HttpPost httpPost = new HttpPost(url);
            //设置请求头
            httpPost.setHeader("Content-Type","multipart/form-data; boundary="+boundary);

            //HttpEntity builder
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            //字符编码
            builder.setCharset(Charset.forName("UTF-8"));
            //模拟浏览器
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
            //boundary
            builder.setBoundary(boundary);
            //multipart/form-data
            builder.addPart("multipartFile",new FileBody(filePath));
            // binary
//            builder.addBinaryBody("name=\"multipartFile\"; filename=\"test.docx\"", new FileInputStream(file), ContentType.MULTIPART_FORM_DATA, fileName);// 文件流
//            //其他参数
//            builder.addTextBody("filename", fileName,  ContentType.create("text/plain", Consts.UTF_8));
            //HttpEntity
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);
            // 执行提交
            HttpResponse response = httpClient.execute(httpPost);
            //响应
            HttpEntity responseEntity = response.getEntity();
            if (responseEntity != null) {
                // 将响应内容转换为字符串
                result = EntityUtils.toString(responseEntity, Charset.forName("UTF-8"));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.err.println("result"+result);
//        return result;
    }

    public static void main(String[] args) {
        uploadFile();
    }
}
调用方法只需要传url和cookie即可，有需要可以把FIle对象作为形参