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java请求http

发布时间: 2021-03-20 21:36:45

Ⅰ java 怎么接收http请求

用servlet接收。
具体步骤是写一个类继承HttpServlet，如果是接收get请求就重写doGet(HttpServletRequest,HttpServletResponse),接收post就重写doPost(HttpServletRequest,HttpServletResponse)，共同处理post和get就重写service(HttpServletRequest,HttpServletResponse)
其次在web.xml定义servlet标签，以及你这个servlet要处理的请求mapping
最后把项目部署在tomcat之类的web容器中即可。
如果使用框架的话就另当别论了，比如spring 的DispatcherServlet。当然你也可以自己写servlet。

Ⅱ java如何调用对方http接口新手虚心求教

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";
//妙兜测试接口
publicstaticfinalStringPOST_URL="http://121.40.204.191:8180/mdserver/service/installLock";

/**
*接口调用GET
*/
(){
try{
URLurl=newURL(GET_URL);//把字符串转换为URL请求地址
HttpURLConnectionconnection=(HttpURLConnection)url.openConnection();//打开连接
connection.connect();//连接会话
//获取输入流
BufferedReaderbr=newBufferedReader(newInputStreamReader(connection.getInputStream(),"UTF-8"));
Stringline;
StringBuildersb=newStringBuilder();
while((line=br.readLine())!=null){//循环读取流
sb.append(line);
}
br.close();//关闭流
connection.disconnect();//断开连接
System.out.println(sb.toString());
}catch(Exceptione){
e.printStackTrace();
System.out.println("失败!");
}
}

/**
*接口调用POST
*/
(){
try{
URLurl=newURL(POST_URL);

//将url以open方法返回的urlConnection连接强转为HttpURLConnection连接(标识一个url所引用的远程对象连接)
HttpURLConnectionconnection=(HttpURLConnection)url.openConnection();//此时cnnection只是为一个连接对象,待连接中

//设置连接输出流为true,默认false(post请求是以流的方式隐式的传递参数)
connection.setDoOutput(true);

//设置连接输入流为true
connection.setDoInput(true);

//设置请求方式为post
connection.setRequestMethod("POST");

//post请求缓存设为false
connection.setUseCaches(false);

//设置该HttpURLConnection实例是否自动执行重定向
connection.setInstanceFollowRedirects(true);

//设置请求头里面的各个属性(以下为设置内容的类型,设置为经过urlEncoded编码过的from参数)
//application/x-javascripttext/xml->xml数据application/x-javascript->json对象application/x-www-form-urlencoded->表单数据
//;charset=utf-8必须要，不然妙兜那边会出现乱码【★★★★★】
connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded;charset=utf-8");

//建立连接(请求未开始,直到connection.getInputStream()方法调用时才发起,以上各个参数设置需在此方法之前进行)
connection.connect();

//创建输入输出流,用于往连接里面输出携带的参数,(输出内容为?后面的内容)
DataOutputStreamdataout=newDataOutputStream(connection.getOutputStream());

Stringapp_key="app_key="+URLEncoder.encode("","utf-8");//已修改【改为错误数据，以免信息泄露】
Stringagt_num="&agt_num="+URLEncoder.encode("10111","utf-8");//已修改【改为错误数据，以免信息泄露】
Stringpid="&pid="+URLEncoder.encode("BLZXA150401111","utf-8");//已修改【改为错误数据，以免信息泄露】
Stringdepartid="&departid="+URLEncoder.encode("10007111","utf-8");//已修改【改为错误数据，以免信息泄露】
Stringinstall_lock_name="&install_lock_name="+URLEncoder.encode("南天大门","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;

//将参数输出到连接
dataout.writeBytes(parm);

//输出完成后刷新并关闭流
dataout.flush();
dataout.close();//重要且易忽略步骤(关闭流,切记!)

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

//连接发起请求,处理服务器响应(从连接获取到输入流并包装为bufferedReader)
BufferedReaderbf=newBufferedReader(newInputStreamReader(connection.getInputStream(),"UTF-8"));
Stringline;
StringBuildersb=newStringBuilder();//用来存储响应数据

//循环读取流,若不到结尾处
while((line=bf.readLine())!=null){
//sb.append(bf.readLine());
sb.append(line).append(System.getProperty("line.separator"));
}
bf.close();//重要且易忽略步骤(关闭流,切记!)
connection.disconnect();//销毁连接
System.out.println(sb.toString());

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

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

Ⅲ java怎么主动发送http请求

实现思路就是先定义请求头内容，之后进行请求头设置。

定义请求头回

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

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

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

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

给HttpPost 设置请求头

HttpPost httpPost = new HttpPost("地址");

if (headers != null) {

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

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

}

备注：只答需要在map中设置相应的请求头内容即可。根据实际需要修改即可

Ⅳ java HTTP请求处理

javax.servlet.http.HttpResponse类用于产生返回页面.通过HttpResponse定义的方法getOutputStream()可以获得ServletOutputStream的实例,这样用户就可以利用ServletOutputStream.write方法向输出流中写入返回页面的内容. 但是ServletOutputStream使用的是缺省的编码方式,如果要使返回页面中的中文字符能够正常显示,最好显示地指定所用的字符编码方式. 通常需要构造一个 OutputStreamWriter , 例程如下:

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("这是测试");

ow.flush();

ow.close();

}

Ⅳ java 接受http请求

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请求

// 这里写你接收request请求后要处理的操作

}

/**

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

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

// 这里写你接收request请求后要处理的操作

}

Ⅵ java模拟http请求指定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) {

}

}
大体上就是这样了。

Ⅶ java如何调用对方http接口

你是指发送http请求吗，可以使用Apache 的 HttpClient

//构建HttpClient实例
CloseableHttpClienthttpclient=HttpClients.createDefault();//设置请求超时时间
RequestConfigrequestConfig=RequestConfig.custom().setSocketTimeout(60000).setConnectTimeout(60000).setConnectionRequestTimeout(60000).build();//指定POST请求
HttpPosthttppost=newHttpPost(url);
httppost.setConfig(requestConfig);//包装请求体
List<NameValuePair>params=newArrayList<NameValuePair>();params.addAll(content);
HttpEntityrequest=newUrlEncodedFormEntity(params,"UTF-8");//发送请求
httppost.setEntity(request);
=httpclient.execute(httppost);//读取响应
HttpEntityentity=httpResponse.getEntity();Stringresult=null;if(entity!=null){
result=EntityUtils.toString(entity,"UTF-8");
}

Ⅷ Java实现拦截HTTP请求的几种方式

在Java的服务端开发当中，拦截器是很常见的业务场景，这里对Java开发当中几种常见的拦截器的实现方式进行记录和分析。案例说明基于Spring Boot环境。
一：实现javax.servlet.Filter接口（使用过滤器方式拦截请求）
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 耗时："+(new Date().getTime()-start));System.out.println("time filter finish");}@Overridepublic void destroy() {System.out.println("time filter destroy");}}

如使用@Compent注解声明不需要加入其它配置即可使得拦截器生效，但是默认拦截/*，会拦截所有请求。
二：使用@Bean注入自定义拦截器，依然上面的代码，去掉@Compent注解，创建TimeWebConfig配置类：
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;}}

上面这两种拦截请求的实现是基于JavaEE提供的Filter接口实现的，缺点在于，该拦截器实际上是一个过滤器，执行代码的方法doFilter只提供了request，response等参数，当请求进入被过滤器拦截的时候，我们并不知道这个请求是由哪个控制器的哪个方法来执行的。
三：使用springMVC提供的拦截器，实现org.springframework.web.servlet.HandlerInterceptor接口：
创建自定义的拦截器：
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 耗时："+(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 耗时："+(new Date().getTime()-start));System.out.println("ex is:"+e);}}

创建配置类：
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/*");}}

此种方式的拦截器当中我们能够获取拦截的请求对应的类和方法的相关信息，缺点在于该handler对象无法获取具体执行方法的参数信息。
四：利用Spring的切面（AOP）实现拦截器：
引入jar包：
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId></dependency>

创建切片类：
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();//具体方法的返回值System.out.println("aspect 耗时："+(new Date().getTime()-start));System.out.println("time aspect end");return obj;}}
aspectj基于AOP实现的拦截器功能十分强大，具体详解请参考spring官网网站的文档。

Ⅸ 怎么用java写一个http接口

一个servlet接口就可以了啊：

HTTP Header 请求实例

下面的实例使用 HttpServletRequest 的getHeaderNames()方法读取 HTTP 头信息。该方法返回一个枚举，包含与当前的 HTTP 请求相关的头信息。

一旦我们有一个枚举，我们可以以标准方式循环枚举，使用hasMoreElements()方法来确定何时停止，使用nextElement()方法来获取每个参数的名称。

//导入必需的java库
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")

//扩展HttpServlet类
{

	//处理GET方法请求的方法
	publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException
	{
		//设置响应内容类型
		response.setContentType("text/html;charset=UTF-8");

		PrintWriterout=response.getWriter();
		Stringtitle="HTTPHeader请求实例-菜鸟教程实例";
		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名称</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>");
	}
	//处理POST方法请求的方法
	publicvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{
		doGet(request,response);
	}
}

Ⅹ 怎样编写http请求的java程序

目前web上的消息通讯方式主要有以下几种。轮询，长连接，websocket轮询：隔一段时间访问服务器，服务器不管有没有新消息都立刻返回。长连接：页面向服务器发出请求，由服务器决定什么时候返回。（如果有新消息则立刻返回，没有的话就保持连接，直到有新消息才返回）websocket：类似JavaSocket，由Http请求模拟实现的socket。要实现长连接的关键就是：由服务器端决定什么时候返回数据。比如在servlet中。doGet(){Thread.sleep(30000);return}这就是一个长连接的例子，只是没有任何意义而已。你要做的就是在doGet中阻塞住，while(!hasNewMsg){sleep(500)}returnnewMsg当然你的ajax超时时间要设置长一点。如果可以的话，最好可以使用websocket。

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