Android编程使用HTTP协议与TCP协议实现上传文件的方法
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2023-12-18 09:16:58
本文实例讲述了android编程使用http协议与tcp协议实现上传文件的方法。分享给大家供大家参考,具体如下:
android上传文件有两种方式,第一种是基于http协...
本文实例讲述了android编程使用http协议与tcp协议实现上传文件的方法。分享给大家供大家参考,具体如下:
android上传文件有两种方式,第一种是基于http协议的httpurlconnection,第二种是基于tcp协议的socket。 这两种方式的区别是使用httpurlconnection上传时内部有缓存机制,如果上传较大文件会导致内存溢出。如果用tcp协议socket方式上传就会解决这种弊端。
http协议httpurlconnection
1. 通过url封装路径打开一个httpurlconnection
2.设置请求方式以及头字段:content-type、content-length、host
3.拼接数据发送
示例:
private static final string boundary = "---------------------------7db1c523809b2";//数据分割线 public boolean uploadhttpurlconnection(string username, string password, string path) throws exception { //找到sdcard上的文件 file file = new file(environment.getexternalstoragedirectory(), path); //仿http协议发送数据方式进行拼接 stringbuilder sb = new stringbuilder(); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"username\"" + "\r\n"); sb.append("\r\n"); sb.append(username + "\r\n"); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"password\"" + "\r\n"); sb.append("\r\n"); sb.append(password + "\r\n"); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"file\"; filename=\"" + path + "\"" + "\r\n"); sb.append("content-type: image/pjpeg" + "\r\n"); sb.append("\r\n"); byte[] before = sb.tostring().getbytes("utf-8"); byte[] after = ("\r\n--" + boundary + "--\r\n").getbytes("utf-8"); url url = new url("http://192.168.1.16:8080/14_web/servlet/loginservlet"); httpurlconnection conn = (httpurlconnection) url.openconnection(); conn.setrequestmethod("post"); conn.setrequestproperty("content-type", "multipart/form-data; boundary=" + boundary); conn.setrequestproperty("content-length", string.valueof(before.length + file.length() + after.length)); conn.setrequestproperty("host", "192.168.1.16:8080"); conn.setdooutput(true); outputstream out = conn.getoutputstream(); inputstream in = new fileinputstream(file); out.write(before); byte[] buf = new byte[1024]; int len; while ((len = in.read(buf)) != -1) out.write(buf, 0, len); out.write(after); in.close(); out.close(); return conn.getresponsecode() == 200; }
tcp协议socket
1.我们可以使用socket发送tcp请求,将上传数据分段发送
示例:
public boolean uploadbysocket(string username, string password, string path) throws exception { // 根据path找到sdcard中的文件 file file = new file(environment.getexternalstoragedirectory(), path); // 组装表单字段和文件之前的数据 stringbuilder sb = new stringbuilder(); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"username\"" + "\r\n"); sb.append("\r\n"); sb.append(username + "\r\n"); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"password\"" + "\r\n"); sb.append("\r\n"); sb.append(password + "\r\n"); sb.append("--" + boundary + "\r\n"); sb.append("content-disposition: form-data; name=\"file\"; filename=\"" + path + "\"" + "\r\n"); sb.append("content-type: image/pjpeg" + "\r\n"); sb.append("\r\n"); // 文件之前的数据 byte[] before = sb.tostring().getbytes("utf-8"); // 文件之后的数据 byte[] after = ("\r\n--" + boundary + "--\r\n").getbytes("utf-8"); url url = new url("http://192.168.1.199:8080/14_web/servlet/loginservlet"); // 由于httpurlconnection中会缓存数据, 上传较大文件时会导致内存溢出, 所以我们使用socket传输 socket socket = new socket(url.gethost(), url.getport()); outputstream out = socket.getoutputstream(); printstream ps = new printstream(out, true, "utf-8"); // 写出请求头 ps.println("post /14_web/servlet/loginservlet http/1.1"); ps.println("content-type: multipart/form-data; boundary=" + boundary); ps.println("content-length: " + string.valueof(before.length + file.length() + after.length)); ps.println("host: 192.168.1.199:8080"); inputstream in = new fileinputstream(file); // 写出数据 out.write(before); byte[] buf = new byte[1024]; int len; while ((len = in.read(buf)) != -1) out.write(buf, 0, len); out.write(after); in.close(); out.close(); return true; }
搭建服务器,完成上传功能
package cn.test.web.servlet; import java.io.file; import java.io.ioexception; import java.util.list; import javax.servlet.servletexception; import javax.servlet.http.httpservlet; import javax.servlet.http.httpservletrequest; import javax.servlet.http.httpservletresponse; import org.apache.commons.fileupload.fileitem; import org.apache.commons.fileupload.fileitemfactory; import org.apache.commons.fileupload.disk.diskfileitemfactory; import org.apache.commons.fileupload.servlet.servletfileupload; public class loginservlet extends httpservlet { private static final long serialversionuid = 1l; @override public void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { dopost(request, response); } @override public void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { boolean ismultipart = servletfileupload.ismultipartcontent(request); if (ismultipart) try { fileitemfactory factory = new diskfileitemfactory(); servletfileupload upload = new servletfileupload(factory); list<fileitem> items = upload.parserequest(request); file dir = new file(request.getsession().getservletcontext().getrealpath("/web-inf/upload")); //创建目录 dir.mkdir(); for (fileitem item : items) if (item.isformfield()) system.out.println(item.getfieldname() + ": " + item.getstring()); else{ item.write(new file(dir,item.getname().substring(item.getname().lastindexof("\\")+1))); } } catch (exception e) { e.printstacktrace(); } else { system.out.println(request.getmethod()); system.out.println(request.getparameter("username")); system.out.println(request.getparameter("password")); } } }
希望本文所述对大家android程序设计有所帮助。