CloseableHttpClient 和 MultipartFile 配合上传文件

最新推荐文章于 2024-02-22 18:39:55 发布

原创最新推荐文章于 2024-02-22 18:39:55 发布 · 6.8k 阅读

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本文介绍了一个使用Java和Spring框架实现的文件上传功能，包括后台接口的定义、Spring配置的设置、MultipartFile类型的处理以及客户端HTTP请求的构造。此外，还提供了浏览器发送multipart/form-data格式请求的数据样本。

1 后台

（1）java

@RequestMapping(value = "/showapi", method = RequestMethod.POST)
public ResponseEntity showapi(@RequestParam("file") MultipartFile multipartFile) {
        byte[] byteImg = multipartFile.getBytes();

普通的接口，只不过接收参数类型为MultipartFile

（2）spring配置

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="100000" />
    <property name="maxInMemorySize" value="100000" />
</bean>

dispatcherServlet是没有处理multipart/form-data,需要单独配置一个resolver，id="multipartResolver"默认如此设置

（3）maven依赖

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.2.1</version> <!-- makesure correct version here -->
</dependency>

2 客户端

public static String decaptcha(File file) {
    CloseableHttpClient client = HttpClients.createDefault();
    HttpPost post = new HttpPost(ReadProperties.read("captcha.url"));
    RequestConfig config = RequestConfig.custom().setSocketTimeout(30000).setConnectTimeout(20000).build();
    post.setConfig(config);

    FileBody fileBody = new FileBody(file, ContentType.DEFAULT_BINARY);
    MultipartEntityBuilder builder = MultipartEntityBuilder.create();
    builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
    builder.addPart("file", fileBody);

    // 相当于 <input type="file" class="file" name="file">,匹配@RequestParam("file")
    // .addPart()可以设置模拟浏览器<input/>的表单提交

    HttpEntity entity = builder.build();
    post.setEntity(entity);
    String result = "";

    try {
        CloseableHttpResponse e = client.execute(post);
        HttpEntity resEntity = e.getEntity();
        if(entity != null) {
            result = EntityUtils.toString(resEntity);
            System.out.println("response content:" + result);
        }
    } catch (IOException var10) {
        logger.error("请求解析验证码io异常",var10);
        var10.printStackTrace();
    }

    return result;
}