本篇内容主要讲解“HttpClient远程请求struts2的文件流并实现下载的方法”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“HttpClient远程请求struts2的文件流并实现下载的方法”吧!
HttpClientUtil工具类:
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.net.URI;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class HttpClientUtil {
private static final Logger logger = LoggerFactory.getLogger(HttpClientUtil.class);
/**
* 封装HTTP POST方法
*
* @param
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String post(String url, Map<String, String> paramMap) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(url);
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpPost.setConfig(requestConfig);
List<NameValuePair> formparams = setHttpParams(paramMap);
UrlEncodedFormEntity param = new UrlEncodedFormEntity(formparams, "UTF-8");
httpPost.setEntity(param);
HttpResponse response = httpClient.execute(httpPost);
// logger.info("************{}", response);
String httpEntityContent = getHttpEntityContent(response);
// logger.info("************{}", httpEntityContent);
httpPost.abort();
// logger.info("************{}", httpEntityContent);
return httpEntityContent;
}
/**
* 封装HTTP POST方法
*
* @param
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static HttpResponse postForResponse(String url, Map<String, String> paramMap) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(url);
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpPost.setConfig(requestConfig);
List<NameValuePair> formparams = setHttpParams(paramMap);
UrlEncodedFormEntity param = new UrlEncodedFormEntity(formparams, "UTF-8");
httpPost.setEntity(param);
HttpResponse response = httpClient.execute(httpPost);
return response;
}
/**
* 封装HTTP POST方法
*
* @param
* @param （如JSON串）
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String post(String url, String data) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(url);
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpPost.setConfig(requestConfig);
httpPost.setHeader("Content-Type", "text/json; charset=utf-8");
httpPost.setEntity(new StringEntity(URLEncoder.encode(data, "UTF-8")));
HttpResponse response = httpClient.execute(httpPost);
String httpEntityContent = getHttpEntityContent(response);
httpPost.abort();
return httpEntityContent;
}
/**
* 封装HTTP GET方法
*
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String get(String url) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet();
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpGet.setConfig(requestConfig);
httpGet.setURI(URI.create(url));
HttpResponse response = httpClient.execute(httpGet);
String httpEntityContent = getHttpEntityContent(response);
httpGet.abort();
return httpEntityContent;
}
/**
* 封装HTTP GET方法
*
* @param
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String get(String url, Map<String, String> paramMap) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet();
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpGet.setConfig(requestConfig);
List<NameValuePair> formparams = setHttpParams(paramMap);
String param = URLEncodedUtils.format(formparams, "UTF-8");
httpGet.setURI(URI.create(url + "?" + param));
HttpResponse response = httpClient.execute(httpGet);
String httpEntityContent = getHttpEntityContent(response);
httpGet.abort();
return httpEntityContent;
}
/**
* 封装HTTP PUT方法
*
* @param
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String put(String url, Map<String, String> paramMap) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpPut httpPut = new HttpPut(url);
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpPut.setConfig(requestConfig);
List<NameValuePair> formparams = setHttpParams(paramMap);
UrlEncodedFormEntity param = new UrlEncodedFormEntity(formparams, "UTF-8");
httpPut.setEntity(param);
HttpResponse response = httpClient.execute(httpPut);
String httpEntityContent = getHttpEntityContent(response);
httpPut.abort();
return httpEntityContent;
}
/**
* 封装HTTP DELETE方法
*
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String delete(String url) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpDelete httpDelete = new HttpDelete();
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpDelete.setConfig(requestConfig);
httpDelete.setURI(URI.create(url));
HttpResponse response = httpClient.execute(httpDelete);
String httpEntityContent = getHttpEntityContent(response);
httpDelete.abort();
return httpEntityContent;
}
/**
* 封装HTTP DELETE方法
*
* @param
* @param
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public static String delete(String url, Map<String, String> paramMap) throws ClientProtocolException, IOException {
HttpClient httpClient = HttpClients.createDefault();
HttpDelete httpDelete = new HttpDelete();
//设置请求和传输超时时间
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).build();
httpDelete.setConfig(requestConfig);
List<NameValuePair> formparams = setHttpParams(paramMap);
String param = URLEncodedUtils.format(formparams, "UTF-8");
httpDelete.setURI(URI.create(url + "?" + param));
HttpResponse response = httpClient.execute(httpDelete);
String httpEntityContent = getHttpEntityContent(response);
httpDelete.abort();
return httpEntityContent;
}
/**
* 设置请求参数
*
* @param
* @return
*/
private static List<NameValuePair> setHttpParams(Map<String, String> paramMap) {
List<NameValuePair> formparams = new ArrayList<NameValuePair>();
Set<Map.Entry<String, String>> set = paramMap.entrySet();
for (Map.Entry<String, String> entry : set) {
formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
return formparams;
}
/**
* 获得响应HTTP实体内容
*
* @param response
* @return
* @throws IOException
* @throws UnsupportedEncodingException
*/
public static String getHttpEntityContent(HttpResponse response) throws IOException, UnsupportedEncodingException {
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream is = entity.getContent();
BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
String line = br.readLine();
StringBuilder sb = new StringBuilder();
while (line != null) {
sb.append(line + "\n");
line = br.readLine();
}
return sb.toString();
}
return "";
}
}spring跨域请求数据:
/**
* 跨域请求数据
* @param model
* @param code
* @return
*/
@RequestMapping(value = "/getDataFromCost")
public void getDataFromCost(ModelAndView model,Long eprjInfoId,Long cprjInfoId,Integer uploadType,String loginname,String t,String h,String eprjAuthMap){
GenericIdentityBean identityBean = this.genGenericIdentity((IdentityBean)model.getModel().get(WebReviewParam.MODEL_IDENTITY));
UserObject user = userSessionService.getUser(identityBean);
Map<String,String> postData = new HashMap<>();
//costHost = "http://localhost:8080/cost";
String url = costHost+"/token2";
if(user != null) {
Map<String, Object> paramsObject;
try {
paramsObject = this.goToCost(model, 1l);
postData.put("loginname", paramsObject.get("loginname")+"");
postData.put("t", paramsObject.get("t")+"");
postData.put("h", paramsObject.get("h")+"");
postData.put("eprjInfoId", "0");
postData.put("uploadType", "50");
postData.put("cprjInfoId", cprjInfoId+"");
postData.put("isChina", "false");
postData.put("remoteUrl", "down");
} catch (Exception e1) {
e1.printStackTrace();
}
String filename = "备份文件导出.hwp";
if(!UnitChange.isEmpty(loginname)){
try {
filename = URLDecoder.decode(loginname, "utf-8");
} catch (Exception e) {
}
}
try {
HttpResponse postForResponse = HttpClientUtil.postForResponse(url, postData);
HttpEntity entity = postForResponse.getEntity();
if(entity != null) {
InputStream is = entity.getContent();
HttpServletResponse response = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getResponse();
String contentType = "application/x-hwp";
String contentDisposition="attachment;";
filename = URLEncoder.encode(filename, "UTF-8");
contentDisposition+="filename=\""+filename+"\"";
response.setContentType(contentType);
response.setHeader("accept-ranges", "bytes");
response.setHeader("Content-Disposition", contentDisposition);
try {
ServletOutputStream outputStream = response.getOutputStream();
IOUtils.copy(is, outputStream);
outputStream.flush();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (ClientProtocolException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}//获取跨域跳转需要的一些参数
/**
* 跳转造价详细审核页面
* @return
* @throws Exception
*/
@ResponseBody
@RequestMapping(value = "/goToCost")
public Map<String,Object> goToCost(ModelAndView model,Long eprjInfoId) throws Exception{
GenericIdentityBean identityBean = this.genGenericIdentity((IdentityBean)model.getModel().get(WebReviewParam.MODEL_IDENTITY));
UserObject user = userSessionService.getUser(identityBean);
if(UnitChange.isEmpty(user.getSecretKey())) {
user.setSecretKey(UuidUtil.uuid());
userService.update(identityBean, user.getId(), user);
}
Map<String,Object> returnMap = new HashMap<>();
returnMap.put("loginname", user.getUsername());
long t = new Date().getTime();
returnMap.put("t", t);
String hash = MD5.encode16((user.getUsername()+user.getSecretKey()+t).getBytes(Charset.forName("UTF-8")));
returnMap.put("h", hash);
returnMap.put("costHost", costHost);
returnMap.put("costHost2", GlobalParameters.getServerUrl()+"/cost"); //跳转造价路径直接取当前域名+/cost
returnMap.put("returnCode",EprjParam.SUCCESS);
return returnMap;
}html页面和JS:
function downloadFile(url,paramObj){
var xhr = new XMLHttpRequest();
// xhr.open('GET', url, true); // 使用GET方式比较简单，参数直接附在URL上
xhr.open('POST', url, true); //POST的格式相对比较灵活，参数可以有比较多的形式，例如JSON，表单FORM等
xhr.responseType = "blob"; // 返回类型blob
// xhr.setRequestHeader("Content-Type","application/json");//提交的数据为json格式
xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
//后台有使用JWT的token验证,会从请求头中读取"X-token"的值,所以这里在请求头加入"X-token"
xhr.setRequestHeader("X-token", 'Bearer ' + localStorage.getItem(SAVE_AUTH));
// 定义请求完成的处理函数
xhr.onload = function () {
jQuery.messager.progress('close');
// 请求完成
if (this.status === 200) {
// 返回200
var blob = this.response;
var reader = new FileReader();
reader.readAsDataURL(blob); // 转换为base64，可以直接放入a表情href
reader.onload = function (e) {
// 转换完成，创建一个a标签用于下载
var a = document.createElement('a');
a.download = paramObj["cprjName"]+".hwp";
//可以通过导出空文件确认文件最小的长度为700000,如果长度过小,则表示远程抛出异常
if(e.target.result.indexOf("data:application/x-hwp") != -1 &&
e.target.result.length > 700000){
a.href = e.target.result;
$("body").append(a); // 修复firefox中无法触发click
a.click();
$(a).remove();
}else{
$.messager.show({ icon: "info", msg: "备份文件大小异常,可重新尝试备份操作！", position: "topCenter" ,timeout:1000, height:80});
}
}
}else{
$.messager.show({ icon: "info", msg: "备份文件大小异常,可重新尝试备份操作！", position: "topCenter" ,timeout:1000, height:80});
}
};
// 发送ajax请求,案例中我们使用POST的请求格式，参数类型为JSON
var param = {};
xhr.send(null);
jQuery.messager.progress({ title:'请稍候...', text:'正在备份导出,请稍候...', interval:800 });
}
function myDownFun(paramObj){
var url = "./iface/getDataFromCost?cprjInfoId="+paramObj["cprjInfoId"];
var rowData = $('#gcxh').treegrid('getSelected');
url += "&loginname="+encodeURIComponent(encodeURIComponent(rowData.name));
var postData = {};
postData["cprjName"] = rowData.cprjNameText;
downloadFile(url,postData);
// openPostWindow(url,data);
}
//本来可以使用form表单提交的方式,或者a连接的href进行导出,只是这两种方式不好捕捉和处理远程请求的异常exception
//<a class="easyui-linkbutton" href="${object.publicResourcesUrl }" target="_blank"
//title="备份导出" data-options="plain: true,iconCls:'fas fa-file-download e-icon fa-fw'" download>下载</a>
function openPostWindow(url,obj) {
var formStr = '';
//设置样式为隐藏，打开新标签再跳转页面前，如果有可现实的表单选项，用户会看到表单内容数据
formStr = '<form id="downTable" method="POST" action="' + url + '">';
formStr += '<input type="hidden" name="eprjInfoId" value="0" />';
formStr += '<input type="hidden" name="cprjInfoId" value="' + obj["cprjInfoId"] + '" />';
formStr += '<input type="hidden" name="uploadType" value="' + obj["uploadType"] + '" />';
formStr += '</form>';
$('body').append(formStr);
$('#downTable')[0].submit();
$('#downTable').remove();
}跨域访问的方法struts2
<action name="token2" method="token2" class="cost-importAndExportAction">
<result name="myJson" type="json"> <!-- 远程请求进度条信息,这里不用管 -->
<param name="contentType">text/html</param>
<param name="includeProperties">returnCode,message,data.*</param>
<param name="ignoreHierarchy">false</param>
<param name="enableGZIP" >true</param>
</result>
<result type="stroageStream"><!-- 远程请求文件流 -->
<param name="contentDisposition">${contentDisposition}</param>
<param name="contentType">${contentType}</param>
<param name="inputName">inputStream</param>
</result>
<result name="login" type="redirect">/default</result>
</action>java(struts2):
public String token2(){
if(VerifyString.isEmpty(loginname) || eprjInfoId == null) {
return "login";
}
if (t<System.currentTimeMillis()/1000-60) { //1分钟内有效
return "login";
}
UserObject userObject = null;
try {
userObject = userService.findByUsername(null, URLDecoder.decode(loginname, "utf-8"));
} catch (Exception e) {
}
if (userObject==null) {
throw new BaseException(this.getClass(),OrganException.USER_NOT_EXIST,"");
}
String hash
=MD5.encode16((userObject.getUsername()+userObject.getSecretKey()+t).getBytes(Charset.forName("UTF-8")));
if (!hash.equalsIgnoreCase(h)) {
throw new BaseException(this.getClass(),OrganException.USER_NOT_EXIST,"");
}
return this.download();//文件流
}struts2的xml请求配置文件
<action name="download" method="download" class="cost-personnelsAction">
<result type="stroageStream">
<param name="contentDisposition">${contentDisposition}</param>
<param name="contentType">${contentType}</param>
<param name="inputName">inputStream</param>
</result>
</action>文件流:
/**
* 导出文件
* @return
*/
@Permission(authorize=Permission.AUTHORIZE_EXPORT)
public String download()
{
Boolean isError=false;
ActionContext context=ActionContext.getContext();
if (context==null)
{
return ActionSupport.ERROR;
}
Integer fileLength=0;
HttpServletRequest request=(HttpServletRequest)context.get(ServletActionContext.HTTP_REQUEST);
HttpServletResponse response=(HttpServletResponse)context.get(ServletActionContext.HTTP_RESPONSE);;
try
{
String filename = "";
switch (this.uploadType) {
case 50:// 建设项目 工程项目备份导出
{
this.inputStream=cprjInfoService.backup(cprjInfoId, eprjInfoId);
if(this.inputStream != null){
fileLength=this.inputStream.available();
int minLength=700000;//普通工程大小
//备份的建设项目或工程项目小于700000，代表备份文件有异常，报错
if(fileLength<minLength) {
throw new Excpetion(this.getClass(), Cost.COST_ERROR, "备份文件大小异常");
}
}
}
break;
default:
break;
}
if(inputStream != null)
fileLength=inputStream.available();
else
fileLength=0;
String method=request.getMethod();
String userAgent=request.getHeader("User-Agent");
Browser browser=Browser.fromUserAgent(userAgent);
this.contentType=FileContentType.buildContentType(filename);
if("POST".equals(method))
{
filename=URLEncoder.encode(filename, "UTF-8");
}
else
{
switch(browser.getType())
{
case Browser.IE:
filename=URLEncoder.encode(filename, "UTF-8");
break;
default:
filename=new String(filename.getBytes(),"ISO8859-1");
break;
}
}
this.contentDisposition="attachment;";
this.contentDisposition+="filename=\""+filename+"\"";
response.setHeader("accept-ranges", "bytes");
// response.setHeader("content-length", String.valueOf(fileLength));
}catch(Exception e)
{
isError=true;
if(e instanceof BaseException)
{
this.returnCode=((BaseException)e).getCode();
this.message=languageException.toString((BaseException)e);
Log.error(e.getMessage(),e);
}
else
{
Log.error(e.getMessage(),e);
this.returnCode=BaseException.UNKNOWN;
this.message=languageException.toString(e);
}
response.setContentType("text/html;charset=UTF-8");
PrintWriter out;
try {
out = new PrintWriter(response.getWriter());
out.println("<html>");
out.println("<body bgcolor=\"white\">");
out.println("<span class=\"bold\">"+this.message+"</span>");
out.println("</body>");
out.println("</html>");
out.flush();
} catch (Exception e1) {
}
return ERROR;
}
finally
{
if(progress != null && userObject != null)
{
progress.put("progressValue", 102);
progress.put("progressText", "");
userService.notsupSetProgressInfo(userObject, progress);
}
}
if(!isError)
return SUCCESS;
else
return ERROR;到此，相信大家对“HttpClient远程请求struts2的文件流并实现下载的方法”有了更深的了解，不妨来实际操作一番吧！这里是亿速云网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
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