使用User-Agent防止HttpClient发送http请求时403 Forbidden和安全拦截

之前写过一个Java工具类–通过HttpClient发送http请求

最近在访问一个接口的时候被拒绝了。具体信息如下

我们用程序访问我的csdn博客地址

解决方案就是在httpclient发出请求的时候在Header中设置一个User-Agent

HTTP响应头和请求头信息对照表

具体如下

    String userAgent = "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.87 Safari/537.36";    HttpGet httpGet = new HttpGet(url);    httpGet.setHeader("User-Agent",userAgent);    response = httpclient.execute(httpGet);

我电脑的谷歌浏览器User-Agent

加上User-Agent之后访问我的博客地址

完整的代码

HttpUtil.java

package com.jrbac.util;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.apache.http.Consts;import org.apache.http.HttpEntity;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.entity.StringEntity;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.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;/** * Http工具类，发送Http请求， Get请求请将参数放在url中 Post请求请将参数放在Map中 *  * @author 程高伟 * @date 2017年1月5日 下午6:03:50 */public class HttpUtil {    private static final Logger log = LoggerFactory.getLogger(HttpUtil.class);    private static final CloseableHttpClient httpclient = HttpClients.createDefault();    private static final String userAgent = "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.87 Safari/537.36";    /**     * 发送HttpGet请求     *      * @param url     *            请求地址     * @return 返回字符串     */    public static String sendGet(String url) {        String result = null;        CloseableHttpResponse response = null;        try {            HttpGet httpGet = new HttpGet(url);            httpGet.setHeader("User-Agent", userAgent);            response = httpclient.execute(httpGet);            HttpEntity entity = response.getEntity();            if (entity != null) {                result = EntityUtils.toString(entity);            }        } catch (Exception e) {            log.error("处理失败 {}" + e);            e.printStackTrace();        } finally {            if (response != null) {                try {                    response.close();                } catch (IOException e) {                    log.error(e.getMessage());                }            }        }        return result;    }    /**     * 发送HttpPost请求，参数为map     *      * @param url     *            请求地址     * @param map     *            请求参数     * @return 返回字符串     */    public static String sendPost(String url, Map<String, String> map) {        // 设置参数        List<NameValuePair> formparams = new ArrayList<NameValuePair>();        for (Map.Entry<String, String> entry : map.entrySet()) {            formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));        }        // 编码        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(formparams, Consts.UTF_8);        // 取得HttpPost对象        HttpPost httpPost = new HttpPost(url);        // 防止被当成攻击添加的        httpPost.setHeader("User-Agent", userAgent);        // 参数放入Entity        httpPost.setEntity(formEntity);        CloseableHttpResponse response = null;        String result = null;        try {            // 执行post请求            response = httpclient.execute(httpPost);            // 得到entity            HttpEntity entity = response.getEntity();            // 得到字符串            result = EntityUtils.toString(entity);        } catch (IOException e) {            log.error(e.getMessage());        } finally {            if (response != null) {                try {                    response.close();                } catch (IOException e) {                    log.error(e.getMessage());                }            }        }        return result;    }    /**     * 发送HttpPost请求，参数为文件，适用于微信上传素材     *      * @param url     *            请求地址     * @param file     *            上传的文件     * @return 返回字符串     * @throws IOException     * @throws ClientProtocolException     */    public static String sendPost(String url, File file) {        String result = null;        HttpPost httpPost = new HttpPost(url);        // 防止被当成攻击添加的        httpPost.setHeader("User-Agent", userAgent);        MultipartEntityBuilder multipartEntity = MultipartEntityBuilder.create();        multipartEntity.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);        multipartEntity.addPart("media", new FileBody(file));        httpPost.setEntity(multipartEntity.build());        CloseableHttpResponse response = null;        try {            response = httpclient.execute(httpPost);            HttpEntity entity = response.getEntity();            result = EntityUtils.toString(entity);        } catch (IOException e) {            log.error(e.getMessage());        } finally {            // 关闭CloseableHttpResponse            if (response != null) {                try {                    response.close();                } catch (IOException e) {                    log.error(e.getMessage());                }            }        }        return result;    }    /**     * 发送HttpPost请求，参数为json字符串     *      * @param url     * @param jsonStr     * @return     */    public static String sendPost(String url, String jsonStr) {        String result = null;        // 字符串编码        StringEntity entity = new StringEntity(jsonStr, Consts.UTF_8);        // 设置content-type        entity.setContentType("application/json");        HttpPost httpPost = new HttpPost(url);        // 防止被当成攻击添加的        httpPost.setHeader("User-Agent", userAgent);        httpPost.setEntity(entity);        CloseableHttpResponse response = null;        try {            response = httpclient.execute(httpPost);            HttpEntity httpEntity = response.getEntity();            result = EntityUtils.toString(httpEntity);        } catch (IOException e) {            log.error(e.getMessage());        } finally {            // 关闭CloseableHttpResponse            if (response != null) {                try {                    response.close();                } catch (IOException e) {                    log.error(e.getMessage());                }            }        }        return result;    }    /**     * 发送不带参数的HttpPost请求     *      * @param url     * @return     */    public static String sendPost(String url) {        String result = null;        // 得到一个HttpPost对象        HttpPost httpPost = new HttpPost(url);        // 防止被当成攻击添加的        httpPost.setHeader("User-Agent", userAgent);        CloseableHttpResponse response = null;        try {            // 执行HttpPost请求，并得到一个CloseableHttpResponse            response = httpclient.execute(httpPost);            // 从CloseableHttpResponse中拿到HttpEntity            HttpEntity entity = response.getEntity();            // 将HttpEntity转换为字符串            result = EntityUtils.toString(entity);        } catch (IOException e) {            log.error(e.getMessage());        } finally {            // 关闭CloseableHttpResponse            if (response != null) {                try {                    response.close();                } catch (IOException e) {                    log.error(e.getMessage());                }            }        }        return result;    }}

参考文献

HTTP响应头和请求头信息对照表