HttpClient上传下载文件

HttpClient上传下载文件

java

HttpClient

Maven依赖

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.1</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.5.1</version>
</dependency>
<dependency>
    <groupId>eu.medsea.mimeutil</groupId>
    <artifactId>mime-util</artifactId>
    <version>2.1.3</version>
</dependency>
<dependency>
    <groupId>javax</groupId>
    <artifactId>javaee-api</artifactId>
    <version>7.0</version>
</dependency>

上传文件

/**
 * 上传文件
 * 
 * @param url
 *            上传路径
 * @param file
 *            文件路径
 * @param stringBody
 *            附带的文本信息
 * @return 响应结果
 */
public static String upload(String url, String file, String stringBody) {
    String result = "";
    CloseableHttpClient httpclient = null;
    CloseableHttpResponse response = null;
    HttpEntity resEntity = null;
    try {
        httpclient = buildHttpClient();
        HttpPost httppost = new HttpPost(url);
        // 把文件转换成流对象FileBody
        FileBody bin = new FileBody(new File(file));
        StringBody comment = new StringBody(stringBody, ContentType.create(
                "text/plain", Consts.UTF_8));
        // 以浏览器兼容模式运行，防止文件名乱码。
        HttpEntity reqEntity = MultipartEntityBuilder.create()
                .setMode(HttpMultipartMode.BROWSER_COMPATIBLE)
                .addPart("bin", bin).addPart("comment", comment)
                .setCharset(Consts.UTF_8).build();
        httppost.setEntity(reqEntity);
        log.info("executing request " + httppost.getRequestLine());
        response = httpclient.execute(httppost);
        log.info(response.getStatusLine());
        resEntity = response.getEntity();
        if (resEntity != null) {
            log.info("Response content length: "
                    + resEntity.getContentLength());
            result = EntityUtils.toString(resEntity, Consts.UTF_8);
        }
    } catch (Exception e) {
        log.error("executing request " + url + " occursing some error.");
        log.error(e);
    } finally {
        try {
            EntityUtils.consume(resEntity);
            response.close();
            httpclient.close();
        } catch (IOException e) {
            log.error(e);
        }
    }
    return result;
}

下载文件

/**
 * 下载文件
 * @param url 下载url
 * @param fileName 保存的文件名（可以为null）
 */
public static void download(String url, String fileName) {
    String path = "G:/download/";
    CloseableHttpClient httpclient = null;
    CloseableHttpResponse response = null;
    HttpEntity entity = null;
    try {
        httpclient = buildHttpClient();
        HttpGet httpget = new HttpGet(url);
        response = httpclient.execute(httpget);
        entity = response.getEntity();
        // 下载
        if (entity.isStreaming()) {
            String destFileName = "data";
            if (!isBlank(fileName)) {
                destFileName = fileName;
            } else if (response.containsHeader("Content-Disposition")) {
                String dstStr = response.getLastHeader(
                        "Content-Disposition").getValue();
                dstStr = decodeHeader(dstStr);
                //使用正则截取
                Pattern p = Pattern.compile("filename=\"?(.+?)\"?$");
                Matcher m = p.matcher(dstStr);
                if (m.find()) {
                    destFileName = m.group(1);
                }
            } else {
                destFileName = url.substring(url.lastIndexOf("/") + 1);
            }
            log.info("downloading file: " + destFileName);
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(path + destFileName);
                entity.writeTo(fos);
            } finally {
                fos.close();
            }
            log.info("download complete");
        } else {
            log.error("Not Found");
            log.info(EntityUtils.toString(entity));
        }
    } catch (Exception e) {
        log.error("downloading file from " + url + " occursing some error.");
        log.error(e);
    } finally {
        try {
            EntityUtils.consume(entity);
            response.close();
            httpclient.close();
        } catch (IOException e) {
            log.error(e);
        }
    }
}

可信任的SSL的HttpClient构建方法

/**
 * 构建可信任的https的HttpClient
 * 
 * @return
 * @throws Exception
 */
public static CloseableHttpClient buildHttpClient() throws Exception {
    SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null,
            new TrustStrategy() {
                @Override
                public boolean isTrusted(X509Certificate[] arg0, String arg1)
                        throws CertificateException {
                    return true;
                }
            }).build();
    SSLConnectionSocketFactory sslSocketFactory = new SSLConnectionSocketFactory(
            sslContext, new NoopHostnameVerifier());
    Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder
            .<ConnectionSocketFactory> create()
            .register("http",
                    PlainConnectionSocketFactory.getSocketFactory())
            .register("https", sslSocketFactory).build();
    PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(
            socketFactoryRegistry);
    // set longer timeout value
    RequestConfig requestConfig = RequestConfig.custom()
            .setSocketTimeout(DEFAULT_TIMEOUT)
            .setConnectTimeout(DEFAULT_TIMEOUT)
            .setConnectionRequestTimeout(DEFAULT_TIMEOUT).build();
    CloseableHttpClient httpclient = HttpClients.custom()
            .setSSLContext(sslContext)
            .setConnectionManager(connectionManager)
            .setDefaultRequestConfig(requestConfig).build();
    return httpclient;
}

辅助方法

// 判断字符串是否为空
private static boolean isBlank(String str) {
    int strLen;
    if (str == null || (strLen = str.length()) == 0) {
        return true;
    }
    for (int i = 0; i < strLen; i++) {
        if ((Character.isWhitespace(str.charAt(i)) == false)) {
            return false;
        }
    }
    return true;
}
// 将header信息按照
// 1,iso-8859-1转utf-8;2,URLDecoder.decode;3,MimeUtility.decodeText;
// 做处理，处理后的string就为编码正确的header信息（包括中文等）
private static String decodeHeader(String header)
        throws UnsupportedEncodingException {
    return MimeUtility.decodeText(URLDecoder.decode(
            new String(header.getBytes(Consts.ISO_8859_1), Consts.UTF_8),
            UTF_8));
}

http://stackoverflow.com/questions/10960409/how-do-i-save-a-file-downloaded-with-httpclient-into-a-specific-folder