HttpClient发送http请求以及上传文件

最新推荐文章于 2025-10-29 16:26:23 发布

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#HttpClient #java #file

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1 篇文章

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本文介绍了一种在Java中封装HTTP请求的方法，包括普通请求和包含文件上传的请求。通过示例代码展示了如何创建请求体，并使用HttpClient发送POST请求。

1.封装请求体

封装普通请求体

private UrlEncodedFormEntity getUrlEntry(Map<String, Object> param) throws UnsupportedEncodingException {
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        Iterator<String> iterator = param.keySet().iterator();
        while (iterator.hasNext()) {
            String key = iterator.next();
            params.add(new BasicNameValuePair(key, (String) param.get(key)));
        }
        UrlEncodedFormEntity uefEntity = new UrlEncodedFormEntity(params, "UTF-8");
        return uefEntity;
    }

封装上传文件请求体

private MultipartEntity getMutipartEntry(Map<String, Object> param, File file) throws UnsupportedEncodingException {
        if (file == null) {
            throw new IllegalArgumentException("文件不能为空");
        }
        FileBody fileBody = new FileBody(file);
        FormBodyPart filePart = new FormBodyPart("file", fileBody);
        MultipartEntity multipartEntity = new MultipartEntity();
        multipartEntity.addPart(filePart);

        Iterator<String> iterator = param.keySet().iterator();
        while (iterator.hasNext()) {
            String key = iterator.next();
            FormBodyPart field = new FormBodyPart(key, new StringBody((String) param.get(key)));
            multipartEntity.addPart(field);

        }
        return multipartEntity;
    }

2.发送请求

发送普通请求

public String postUrl(String url,Map<String, Object> param) throws ClientProtocolException, IOException {
        String res = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httppost = new HttpPost(url);
        UrlEncodedFormEntity uefEntity = getUrlEntry(param);
        httppost.setEntity(uefEntity);
        CloseableHttpResponse response = httpClient.execute(httppost);
        HttpEntity entity = response.getEntity();
        if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
            res = EntityUtils.toString(entity, "UTF-8");
            response.close();
        } else {
            res = EntityUtils.toString(entity, "UTF-8");
            response.close();
            throw new IllegalArgumentException(res);
        }

        return res;
    }

发送上传文件请求

public String postFile(String url,Map<String, Object> param, File file) throws ClientProtocolException, IOException {
        String res = null;
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httppost = new HttpPost(url);
        httppost.setEntity(getMutipartEntry(param,file));
        CloseableHttpResponse response = httpClient.execute(httppost);
        HttpEntity entity = response.getEntity();
        if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
            res = EntityUtils.toString(entity, "UTF-8");
            response.close();
        } else {
            res = EntityUtils.toString(entity, "UTF-8");
            response.close();
            throw new IllegalArgumentException(res);
        }
        return res;
    }