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java請求http

發布時間: 2021-03-20 21:36:45

Ⅰ java 怎麼接收http請求

用servlet接收。
具體步驟是寫一個類繼承HttpServlet，如果是接收get請求就重寫doGet(HttpServletRequest,HttpServletResponse),接收post就重寫doPost(HttpServletRequest,HttpServletResponse)，共同處理post和get就重寫service(HttpServletRequest,HttpServletResponse)
其次在web.xml定義servlet標簽，以及你這個servlet要處理的請求mapping
最後把項目部署在tomcat之類的web容器中即可。
如果使用框架的話就另當別論了，比如spring 的DispatcherServlet。當然你也可以自己寫servlet。

Ⅱ java如何調用對方http介面新手虛心求教

importjava.io.BufferedReader;
importjava.io.DataOutputStream;
importjava.io.InputStreamReader;
importjava.net.HttpURLConnection;
importjava.net.URL;
importjava.net.URLEncoder;

publicclassDemoTest1{

publicstaticfinalStringGET_URL="http://112.4.27.9/mall-back/if_user/store_list?storeId=32";
//publicstaticfinalStringPOST_URL="http://112.4.27.9/mall-back/if_user/store_list";
//妙兜測試介面
publicstaticfinalStringPOST_URL="http://121.40.204.191:8180/mdserver/service/installLock";

/**
*介面調用GET
*/
(){
try{
URLurl=newURL(GET_URL);//把字元串轉換為URL請求地址
HttpURLConnectionconnection=(HttpURLConnection)url.openConnection();//打開連接
connection.connect();//連接會話
//獲取輸入流
BufferedReaderbr=newBufferedReader(newInputStreamReader(connection.getInputStream(),"UTF-8"));
Stringline;
StringBuildersb=newStringBuilder();
while((line=br.readLine())!=null){//循環讀取流
sb.append(line);
}
br.close();//關閉流
connection.disconnect();//斷開連接
System.out.println(sb.toString());
}catch(Exceptione){
e.printStackTrace();
System.out.println("失敗!");
}
}

/**
*介面調用POST
*/
(){
try{
URLurl=newURL(POST_URL);

//將url以open方法返回的urlConnection連接強轉為HttpURLConnection連接(標識一個url所引用的遠程對象連接)
HttpURLConnectionconnection=(HttpURLConnection)url.openConnection();//此時cnnection只是為一個連接對象,待連接中

//設置連接輸出流為true,默認false(post請求是以流的方式隱式的傳遞參數)
connection.setDoOutput(true);

//設置連接輸入流為true
connection.setDoInput(true);

//設置請求方式為post
connection.setRequestMethod("POST");

//post請求緩存設為false
connection.setUseCaches(false);

//設置該HttpURLConnection實例是否自動執行重定向
connection.setInstanceFollowRedirects(true);

//設置請求頭裡面的各個屬性(以下為設置內容的類型,設置為經過urlEncoded編碼過的from參數)
//application/x-javascripttext/xml->xml數據application/x-javascript->json對象application/x-www-form-urlencoded->表單數據
//;charset=utf-8必須要，不然妙兜那邊會出現亂碼【★★★★★】
connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded;charset=utf-8");

//建立連接(請求未開始,直到connection.getInputStream()方法調用時才發起,以上各個參數設置需在此方法之前進行)
connection.connect();

//創建輸入輸出流,用於往連接裡面輸出攜帶的參數,(輸出內容為?後面的內容)
DataOutputStreamdataout=newDataOutputStream(connection.getOutputStream());

Stringapp_key="app_key="+URLEncoder.encode("","utf-8");//已修改【改為錯誤數據，以免信息泄露】
Stringagt_num="&agt_num="+URLEncoder.encode("10111","utf-8");//已修改【改為錯誤數據，以免信息泄露】
Stringpid="&pid="+URLEncoder.encode("BLZXA150401111","utf-8");//已修改【改為錯誤數據，以免信息泄露】
Stringdepartid="&departid="+URLEncoder.encode("10007111","utf-8");//已修改【改為錯誤數據，以免信息泄露】
Stringinstall_lock_name="&install_lock_name="+URLEncoder.encode("南天大門","utf-8");
Stringinstall_address="&install_address="+URLEncoder.encode("北京育新","utf-8");
Stringinstall_gps="&install_gps="+URLEncoder.encode("116.350888,40.011001","utf-8");
Stringinstall_work="&install_work="+URLEncoder.encode("小李","utf-8");
Stringinstall_telete="&install_telete="+URLEncoder.encode("13000000000","utf-8");
Stringintall_comm="&intall_comm="+URLEncoder.encode("一切正常","utf-8");

//格式parm=aaa=111&bbb=222&ccc=333&ddd=444
Stringparm=app_key+agt_num+pid+departid+install_lock_name+install_address+install_gps+install_work+install_telete+intall_comm;

//將參數輸出到連接
dataout.writeBytes(parm);

//輸出完成後刷新並關閉流
dataout.flush();
dataout.close();//重要且易忽略步驟(關閉流,切記!)

//System.out.println(connection.getResponseCode());

//連接發起請求,處理伺服器響應(從連接獲取到輸入流並包裝為bufferedReader)
BufferedReaderbf=newBufferedReader(newInputStreamReader(connection.getInputStream(),"UTF-8"));
Stringline;
StringBuildersb=newStringBuilder();//用來存儲響應數據

//循環讀取流,若不到結尾處
while((line=bf.readLine())!=null){
//sb.append(bf.readLine());
sb.append(line).append(System.getProperty("line.separator"));
}
bf.close();//重要且易忽略步驟(關閉流,切記!)
connection.disconnect();//銷毀連接
System.out.println(sb.toString());

}catch(Exceptione){
e.printStackTrace();
}
}

publicstaticvoidmain(String[]args){
//httpURLConectionGET();
httpURLConnectionPOST();
}
}

Ⅲ java怎麼主動發送http請求

實現思路就是先定義請求頭內容，之後進行請求頭設置。

定義請求頭回

LinkedHashMap<String,String> headers = new LinkedHashMap<String,String>();

headers.put("Content-type","text/xml");

headers.put("Cache-Control", "no-cache");

headers.put("Connection", "close");

給HttpPost 設置請求頭

HttpPost httpPost = new HttpPost("地址");

if (headers != null) {

for (String key : headers.keySet()) {

httpPost.setHeader(key, headers.get(key));

}

備註：只答需要在map中設置相應的請求頭內容即可。根據實際需要修改即可

Ⅳ java HTTP請求處理

javax.servlet.http.HttpResponse類用於產生返回頁面.通過HttpResponse定義的方法getOutputStream()可以獲得ServletOutputStream的實例,這樣用戶就可以利用ServletOutputStream.write方法向輸出流中寫入返回頁面的內容. 但是ServletOutputStream使用的是預設的編碼方式,如果要使返回頁面中的中文字符能夠正常顯示,最好顯示地指定所用的字元編碼方式. 通常需要構造一個 OutputStreamWriter , 常式如下:

public void doGet (HttpServletRequest req, HttpServletResponse res)

throws ServletException, IOException

{

res.setContentType("text/html");

ServletOutputStream out = res.getOutputStream();

OutputStreamWriter ow = new OutputStreamWriter(out,"GB2312");

ow.write("這是測試");

ow.flush();

ow.close();

}

Ⅳ java 接受http請求

使用servlet

public class Test extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

* @see HttpServlet#HttpServlet()

public Test() {

super();

// TODO Auto-generated constructor stub

}

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//接收get請求

// 這里寫你接收request請求後要處理的操作

}

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//接收post請求

// 這里寫你接收request請求後要處理的操作

}

Ⅵ java模擬http請求指定url

HttpClient httpclient = new DefaultHttpClient();

HttpGet httpget = new HttpGet("http://localhost/");

HttpResponse response = httpclient.execute(httpget);

HttpEntity entity = response.getEntity();

if (entity != null) {

InputStream instream = entity.getContent();

int l;

byte[] tmp = new byte[2048];

while ((l = instream.read(tmp)) != -1) {

}

}
大體上就是這樣了。

Ⅶ java如何調用對方http介面

你是指發送http請求嗎，可以使用Apache 的 HttpClient

//構建HttpClient實例
CloseableHttpClienthttpclient=HttpClients.createDefault();//設置請求超時時間
RequestConfigrequestConfig=RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).setConnectionRequestTimeout(60000).build();//指定POST請求
HttpPosthttppost=newHttpPost(url);
httppost.setConfig(requestConfig);//包裝請求體
List<NameValuePair>params=newArrayList<NameValuePair>();params.addAll(content);
HttpEntityrequest=newUrlEncodedFormEntity(params,"UTF-8");//發送請求
httppost.setEntity(request);
=httpclient.execute(httppost);//讀取響應
HttpEntityentity=httpResponse.getEntity();Stringresult=null;if(entity!=null){
result=EntityUtils.toString(entity,"UTF-8");
}

Ⅷ Java實現攔截HTTP請求的幾種方式

在Java的服務端開發當中，攔截器是很常見的業務場景，這里對Java開發當中幾種常見的攔截器的實現方式進行記錄和分析。案例說明基於Spring Boot環境。
一：實現javax.servlet.Filter介面（使用過濾器方式攔截請求）
import org.springframework.stereotype.Component;import javax.servlet.*;import java.io.IOException;import java.util.Date;@Componentpublic class TimeInterceptor implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {System.out.println("time filter init");}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {System.out.println("time filter start");long start = new Date().getTime();filterChain.doFilter(servletRequest, servletResponse);System.out.println("time filter 耗時："+(new Date().getTime()-start));System.out.println("time filter finish");}@Overridepublic void destroy() {System.out.println("time filter destroy");}}

如使用@Compent註解聲明不需要加入其它配置即可使得攔截器生效，但是默認攔截/*，會攔截所有請求。
二：使用@Bean注入自定義攔截器，依然上面的代碼，去掉@Compent註解，創建TimeWebConfig配置類：
import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import java.util.ArrayList;import java.util.List;@Configurationpublic class TimeWebConfig {@Beanpublic FilterRegistrationBean timeFilter(){FilterRegistrationBean registrationBean = new FilterRegistrationBean();TimeInterceptor interceptor = new TimeInterceptor();registrationBean.setFilter(interceptor);List<String> urls = new ArrayList<>();urls.add("/user/*");registrationBean.setUrlPatterns(urls);return registrationBean;}}

上面這兩種攔截請求的實現是基於JavaEE提供的Filter介面實現的，缺點在於，該攔截器實際上是一個過濾器，執行代碼的方法doFilter只提供了request，response等參數，當請求進入被過濾器攔截的時候，我們並不知道這個請求是由哪個控制器的哪個方法來執行的。
三：使用springMVC提供的攔截器，實現org.springframework.web.servlet.HandlerInterceptor介面：
創建自定義的攔截器：
import org.springframework.stereotype.Component;import org.springframework.web.method.HandlerMethod;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.util.Date;@Componentpublic class MyInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler) throws Exception {System.out.println("preHandler");System.out.println(((HandlerMethod) handler).getBean().getClass().getName());System.out.println(((HandlerMethod) handler).getMethod().getName());httpServletRequest.setAttribute("start", new Date().getTime());return true;}@Overridepublic void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {System.out.println("postHandler");Long start = (Long) httpServletRequest.getAttribute("start");System.out.println("time interceptor 耗時："+(new Date().getTime()-start));}@Overridepublic void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {System.out.println("afterCompletion");Long start = (Long) httpServletRequest.getAttribute("start");System.out.println("time interceptor 耗時："+(new Date().getTime()-start));System.out.println("ex is:"+e);}}

創建配置類：
import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;@Configurationpublic class WebConfig extends WebMvcConfigurerAdapter {@Autowiredprivate MyInterceptor interceptor;@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(interceptor).addPathPatterns("/user/*").excludePathPatterns("/blog/*");}}

此種方式的攔截器當中我們能夠獲取攔截的請求對應的類和方法的相關信息，缺點在於該handler對象無法獲取具體執行方法的參數信息。
四：利用Spring的切面（AOP）實現攔截器：
引入jar包：
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId></dependency>

創建切片類：
import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.Around;import org.aspectj.lang.annotation.Aspect;import org.springframework.stereotype.Component;import java.util.Date;@Aspect@Componentpublic class TimeAspect {@Around("execution(* com.qinker.controller.UserController.*(..))")public Object handlerControllerMethod(ProceedingJoinPoint point) throws Throwable {System.out.println("time aspect start");long start = new Date().getTime();Object[] args = point.getArgs();for (Object obj : args) {System.out.println("arg is:"+obj);}Object obj = point.proceed();//具體方法的返回值System.out.println("aspect 耗時："+(new Date().getTime()-start));System.out.println("time aspect end");return obj;}}
aspectj基於AOP實現的攔截器功能十分強大，具體詳解請參考spring官網網站的文檔。

Ⅸ 怎麼用java寫一個http介面

一個servlet介面就可以了啊：

HTTP Header 請求實例

下面的實例使用 HttpServletRequest 的getHeaderNames()方法讀取 HTTP 頭信息。該方法返回一個枚舉，包含與當前的 HTTP 請求相關的頭信息。

一旦我們有一個枚舉，我們可以以標准方式循環枚舉，使用hasMoreElements()方法來確定何時停止，使用nextElement()方法來獲取每個參數的名稱。

//導入必需的java庫
importjava.io.IOException;
importjava.io.PrintWriter;
importjava.util.Enumeration;

importjavax.servlet.ServletException;
importjavax.servlet.annotation.WebServlet;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;

@WebServlet("/DisplayHeader")

//擴展HttpServlet類
{

	//處理GET方法請求的方法
	publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException
	{
		//設置響應內容類型
		response.setContentType("text/html;charset=UTF-8");

		PrintWriterout=response.getWriter();
		Stringtitle="HTTPHeader請求實例-菜鳥教程實例";
		StringdocType=
			"<!DOCTYPEhtml>
";
			out.println(docType+
			"<html>
"+
			"<head><metacharset="utf-8"><title>"+title+"</title></head>
"+
			"<bodybgcolor="#f0f0f0">
"+
			"<h1align="center">"+title+"</h1>
"+
			"<tablewidth="100%"border="1"align="center">
"+
			"<trbgcolor="#949494">
"+
			"<th>Header名稱</th><th>Header值</th>
"+
			"</tr>
");

		EnumerationheaderNames=request.getHeaderNames();

		while(headerNames.hasMoreElements()){
			StringparamName=(String)headerNames.nextElement();
			out.print("<tr><td>"+paramName+"</td>
");
			StringparamValue=request.getHeader(paramName);
			out.println("<td>"+paramValue+"</td></tr>
");
		}
		out.println("</table>
</body></html>");
	}
	//處理POST方法請求的方法
	publicvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
		doGet(request,response);
	}
}

Ⅹ 怎樣編寫http請求的java程序

目前web上的消息通訊方式主要有以下幾種。輪詢，長連接，websocket輪詢：隔一段時間訪問伺服器，伺服器不管有沒有新消息都立刻返回。長連接：頁面向伺服器發出請求，由伺服器決定什麼時候返回。（如果有新消息則立刻返回，沒有的話就保持連接，直到有新消息才返回）websocket：類似JavaSocket，由Http請求模擬實現的socket。要實現長連接的關鍵就是：由伺服器端決定什麼時候返回數據。比如在servlet中。doGet(){Thread.sleep(30000);return}這就是一個長連接的例子，只是沒有任何意義而已。你要做的就是在doGet中阻塞住，while(!hasNewMsg){sleep(500)}returnnewMsg當然你的ajax超時時間要設置長一點。如果可以的話，最好可以使用websocket。

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