java连接http的简单介绍
今天给各位分享java连接http的知识，其中也会对进行解释，如果能碰巧解决你现在面临的问题，别忘了关注本站，现在开始吧！
本文目录一览：
如何用java实现HTTP长连接
tomcat9提供了一种叫webSocket的东西，可以实现这个，但是必须要使用tomcat9来支持
另外一个就是运用长轮询，就是前台给后台发一个请求, 然后后台一直不处理, 可以while循环或者sleep(1000), 每隔1秒去检查是否应该返回数据, 如果后台决定要刷新了, 就返回数据, 然后前台接收到返回数据后去刷新你要刷新的东西, 刷新完毕后如果需要, 再次发送这个请求。当然，为了不阻塞其它的ajax请求, 长轮询一般放在一个单独的iframe里
java如何调用对方http接口 新手虚心求教
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class DemoTest1 {
public static final String GET_URL = "";
// public static final String POST_URL = "";
// 妙兜测试接口
public static final String POST_URL = "";
/**
* 接口调用 GET
*/
public static void httpURLConectionGET() {
try {
URL url = new URL(GET_URL); // 把字符串转换为URL请求地址
HttpURLConnection connection = (HttpURLConnection) url.openConnection();// 打开连接
connection.connect();// 连接会话
// 获取输入流
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
String line;
StringBuilder sb = new StringBuilder();
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 (Exception e) {
e.printStackTrace();
System.out.println("失败!");
}
}
/**
* 接口调用 POST
*/
public static void httpURLConnectionPOST () {
try {
URL url = new URL(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)
HttpURLConnection connection = (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-javascript text/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)
DataOutputStream dataout = new DataOutputStream(connection.getOutputStream());
String app_key = "app_key="+ URLEncoder.encode("4f7bf8c8260124e6e9c6bf094951a111", "utf-8"); // 已修改【改为错误数据，以免信息泄露】
String agt_num = "agt_num="+ URLEncoder.encode("10111", "utf-8"); // 已修改【改为错误数据，以免信息泄露】
String pid = "pid="+ URLEncoder.encode("BLZXA150401111", "utf-8"); // 已修改【改为错误数据，以免信息泄露】
String departid = "departid="+ URLEncoder.encode("10007111", "utf-8"); // 已修改【改为错误数据，以免信息泄露】
String install_lock_name = "install_lock_name="+ URLEncoder.encode("南天大门", "utf-8");
String install_address = "install_address="+ URLEncoder.encode("北京育新", "utf-8");
String install_gps = "install_gps="+ URLEncoder.encode("116.350888,40.011001", "utf-8");
String install_work = "install_work="+ URLEncoder.encode("小李", "utf-8");
String install_telete = "install_telete="+ URLEncoder.encode("13000000000", "utf-8");
String intall_comm = "intall_comm="+ URLEncoder.encode("一切正常", "utf-8");
// 格式 parm = aaa=111bbb=222ccc=333ddd=444
String parm = 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)
BufferedReader bf = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
String line;
StringBuilder sb = new StringBuilder(); // 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 (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
// httpURLConectionGET();
httpURLConnectionPOST();
}
}
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。
java如何实现http长连接
通过轮询来实现长连接
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。
http长连接实现代码：
客户端：
package houlei.csdn.keepalive;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.concurrent.ConcurrentHashMap;
/**
* C/S架构的客户端对象，持有该对象，可以随时向服务端发送消息。
* p
* 创建时间：2010-7-18 上午12:17:25
* @author HouLei
* @since 1.0
*/
public class Client {
/**
* 处理服务端发回的对象，可实现该接口。
*/
public static interface ObjectAction{
void doAction(Object obj,Client client);
}
public static final class DefaultObjectAction implements ObjectAction{
public void doAction(Object obj,Client client) {
System.out.println("处理：\t"+obj.toString());//诊断程序是否正常
}
}
public static void main(String[] args) throws UnknownHostException, IOException {
String serverIp = "127.0.0.1";
int port = 65432;
Client client = new Client(serverIp,port);
client.start();
}
private String serverIp;
private int port;
private Socket socket;
private boolean running=false;
private long lastSendTime;
private ConcurrentHashMapClass, ObjectAction actionMapping = new ConcurrentHashMapClass,ObjectAction();
public Client(String serverIp, int port) {
this.serverIp=serverIp;this.port=port;
}
public void start() throws UnknownHostException, IOException {
if(running)return;
socket = new Socket(serverIp,port);
System.out.println("本地端口："+socket.getLocalPort());
lastSendTime=System.currentTimeMillis();
running=true;
new Thread(new KeepAliveWatchDog()).start();
new Thread(new ReceiveWatchDog()).start();
}
public void stop(){
if(running)running=false;
}
/**
* 添加接收对象的处理对象。
* @param cls 待处理的对象，其所属的类。
* @param action 处理过程对象。
*/
public void addActionMap(ClassObject cls,ObjectAction action){
actionMapping.put(cls, action);
}
public void sendObject(Object obj) throws IOException {
ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
oos.writeObject(obj);
System.out.println("发送：\t"+obj);
oos.flush();
}
class KeepAliveWatchDog implements Runnable{
long checkDelay = 10;
long keepAliveDelay = 2000;
public void run() {
while(running){
if(System.currentTimeMillis()-lastSendTimekeepAliveDelay){
try {
Client.this.sendObject(new KeepAlive());
} catch (IOException e) {
e.printStackTrace();
Client.this.stop();
}
lastSendTime = System.currentTimeMillis();
}else{
try {
Thread.sleep(checkDelay);
} catch (InterruptedException e) {
e.printStackTrace();
Client.this.stop();
}
}
}
}
}
class ReceiveWatchDog implements Runnable{
public void run() {
while(running){
try {
InputStream in = socket.getInputStream();
if(in.available()0){
ObjectInputStream ois = new ObjectInputStream(in);
Object obj = ois.readObject();
System.out.println("接收：\t"+obj);//接受数据
ObjectAction oa = actionMapping.get(obj.getClass());
oa = oa==null?new DefaultObjectAction():oa;
oa.doAction(obj, Client.this);
}else{
Thread.sleep(10);
}
} catch (Exception e) {
e.printStackTrace();
Client.this.stop();
}
}
}
}
}
服务端：
package houlei.csdn.keepalive;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ConcurrentHashMap;
/**
* C/S架构的服务端对象。
* p
* 创建时间：2010-7-18 上午12:17:37
* @author HouLei
* @since 1.0
*/
public class Server {
/**
* 要处理客户端发来的对象，并返回一个对象，可实现该接口。
*/
public interface ObjectAction{
Object doAction(Object rev);
}
public static final class DefaultObjectAction implements ObjectAction{
public Object doAction(Object rev) {
System.out.println("处理并返回："+rev);//确认长连接状况
return rev;
}
}
public static void main(String[] args) {
int port = 65432;
Server server = new Server(port);
server.start();
}
private int port;
private volatile boolean running=false;
private long receiveTimeDelay=3000;
private ConcurrentHashMapClass, ObjectAction actionMapping = new ConcurrentHashMapClass,ObjectAction();
private Thread connWatchDog;
public Server(int port) {
this.port = port;
}
public void start(){
if(running)return;
running=true;
connWatchDog = new Thread(new ConnWatchDog());
connWatchDog.start();
}
@SuppressWarnings("deprecation")
public void stop(){
if(running)running=false;
if(connWatchDog!=null)connWatchDog.stop();
}
public void addActionMap(ClassObject cls,ObjectAction action){
actionMapping.put(cls, action);
}
class ConnWatchDog implements Runnable{
public void run(){
try {
ServerSocket ss = new ServerSocket(port,5);
while(running){
Socket s = ss.accept();
new Thread(new SocketAction(s)).start();
}
} catch (IOException e) {
e.printStackTrace();
Server.this.stop();
}
}
}
class SocketAction implements Runnable{
Socket s;
boolean run=true;
long lastReceiveTime = System.currentTimeMillis();
public SocketAction(Socket s) {
this.s = s;
}
public void run() {
while(running run){
if(System.currentTimeMillis()-lastReceiveTimereceiveTimeDelay){
overThis();
}else{
try {
InputStream in = s.getInputStream();
if(in.available()0){
ObjectInputStream ois = new ObjectInputStream(in);
Object obj = ois.readObject();
lastReceiveTime = System.currentTimeMillis();
System.out.println("接收：\t"+obj);
ObjectAction oa = actionMapping.get(obj.getClass());
oa = oa==null?new DefaultObjectAction():oa;
Object out = oa.doAction(obj);
if(out!=null){
ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
oos.writeObject(out);
oos.flush();
}
}else{
Thread.sleep(10);
}
} catch (Exception e) {
e.printStackTrace();
overThis();
}
}
}
}
private void overThis() {
if(run)run=false;
if(s!=null){
try {
s.close();
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("关闭："+s.getRemoteSocketAddress());//关闭长连接
}
}
}
长连接的维持，是要客户端程序，定时向服务端程序，发送一个维持连接包的。
如果，长时间未发送维持连接包，服务端程序将断开连接。
java连接http的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于、java连接http的信息别忘了在本站进行查找喔。