阳光沙滩-让学习编程变得更加简单

安卓网路编程-http协议学习android网络编程相关的知识前，我们先学习一下http协议之前有一篇文章，是java网络编程，大家可以看看JAVA中的网路编程看完上面这篇文章，你就知道了我们今天要了解的

2019-11-22 12:44 · 网络编程 / http / 协议 / java / android

报错 java.lang.NullPointerException:Attempttoinvokevirtualmethod'voidjava.io.OutputStream.close()'onanullobjectreference atcom.example.androidnetwork.PostTestActivity$3.run(PostTestActivity.java:261)publicvoidpostFile(Viewview){newThread(newRunnable(){@Overridepublicvoidrun(){InputStreaminputStream=null;BufferedInputStreambis=null;OutputStreamoutputStream=null;try{Filefile=newFile("/storage/self/primary/Download/u=3340390700,4267772580&fm=173&app=49&f=JPEG.jpg");Stringboundary="--------------------------467592652334333334357333";Stringfilekey="file";Stringfilename=file.getName();Log.e(TAG,"run:"+filename);StringfileType="image/jpeg";URLurl=newURL(BASE_URL+"/file/upload");HttpURLConnectionconnection=(HttpURLConnection)url.openConnection();connection.setRequestMethod("POST");connection.setConnectTimeout(10000);connection.setRequestProperty("User-Agent","Android/"+Build.VERSION.SDK_INT);connection.setRequestProperty("Accept","*/*");connection.setRequestProperty("Cache-Control","no-cache");connection.setRequestProperty("Content-Type","multipart/form-data;boundary="+boundary);connection.setRequestProperty("Connection","keep-alive");connection.setDoOutput(true);connection.setDoInput(true);//连接connection.connect();outputStream=connection.getOutputStream();//准备数据StringBuilderheadersb=newStringBuilder();headersb.append("--");headersb.append(boundary);headersb.append("\r\n");headersb.append("Content-Disposition:form-data;name=\""+filekey+"\";filename=\""+filename+"\"");headersb.append("\r\n");headersb.append("Content-Type:"+fileType);headersb.append("\r\n");headersb.append("\r\n");Log.e(TAG,"run:"+headersb.toString());byte[]bytes=headersb.toString().getBytes("UTF-8");outputStream.write(bytes);//文件内容FileInputStreamfis=newFileInputStream(file);bis=newBufferedInputStream(fis);byte[]buffer=newbyte[1024];intlen;while((len=bis.read(buffer,0,buffer.length))!=-1){outputStream.write(buffer,0,len);}//写尾部信息StringBuilderfootersb=newStringBuilder();headersb.append("\r\n");footersb.append("--");footersb.append(boundary);footersb.append("--");headersb.append("\r\n");headersb.append("\r\n");outputStream.write(footersb.toString().getBytes("UTF-8"));outputStream.flush();intresponseCode=connection.getResponseCode();Log.e(TAG,"run:"+responseCode);if(responseCode==200){inputStream=connection.getInputStream();BufferedReaderbr=newBufferedReader(newInputStreamReader(inputStream));Stringline=br.readLine();Log.e(TAG,"run:"+line);}}catch(Exceptione){e.printStackTrace();}finally{if(bis!=null){try{bis.close();}catch(IOExceptione){e.printStackTrace();}}try{outputStream.close();}catch(IOExceptione){e.printStackTrace();}if(inputStream!=null){try{inputStream.close();}catch(IOExceptione){e.printStackTrace();}}}}}).start();}}

2020-04-02 17:08 · android