android.os.NetworkOnMainThreadException
在搞android開發中過程中。是關於HttpURLConnection鏈接的，我是上傳多個同一個名稱的數據到server，本來在2.3版本號上能夠執行。可是在4.2版本號上就報android.os.NetworkOnMainThreadException異常。無法將數據提交到server。
查了一些資料發現是一個APP假設在主線程中請求網絡操作，將會拋出此異常。Android這個設計是為了防止網絡請求時間過長而導致界面假死的情況發生。
解決方式有兩個，一個是使用StrictMode，二是使用線程來操作網絡請求。
第一種方法：簡單暴力，強制使用，代碼改動簡單（可是很不推薦）
在MainActivity文件的setContentView(R.layout.activity_main)以下加上例如以下代碼
|
2 3 4 |
if
(android.os.Build.VERSION.SDK_INT > 9)
{
StrictMode.ThreadPolicy
policy = new
StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
|
/**
* 表單上傳多值和多圖片
* @param url 鏈接地址
* @param handler 回調handler
* @param valus 值
* @param sameValuNames 存放須要上傳的名字同樣的value
* @param sameValueName 同樣的名字的上傳名稱
* @param imageUrl 圖片路徑（上傳名稱不同）
* @param sameImageUrlName 存放上傳多個圖片（上傳名稱同樣）
* @param sameImageName 存放上傳多個圖片要求上傳名稱同樣
*/
public static void myPostHttpConnection(String myUrl,final Handler handler,final Map<String, String> valus,final Map<String, String> sameValuNames,final String sameValueName,final Map<String, String> imageUrl,final Map<String,
String> sameImageUrlName,final String sameImageName){
//Log.d("TAG", "sameImageUrlName.size()"+sameImageUrlName.size());
//Log.d("TAG", "sameImageName"+sameImageName);
//Log.d("TAG", "sameValueName"+sameValueName);
//Log.d("TAG", "sameValuNames"+sameValuNames.size());
new AsyncTask<String,Void,String>() {
@Override
protected String doInBackground(String... params) {
try {
// 定義數據分隔線
String BOUNDARY = "------------------------7dc2fd5c0894";
// 定義最後數據分隔線
byte[] end_data = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
//Log.d("TAG", "params[0]"+params[0]);
URL url = new URL(params[0]);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent",
"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)");
conn.setRequestProperty("Charsert", "UTF-8");
conn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + BOUNDARY);
StringBuffer myparams=null;
OutputStream out=null;
out = new DataOutputStream(conn.getOutputStream());
myparams = new StringBuffer();
//不同名稱的的參數
if(valus!=null){
//Log.d("TAG", "有bu同樣參數的提交");
Iterator iter = valus.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.Entry) iter.next();
String val = entry.getValue().toString();
String key = entry.getKey().toString();
// Log.d("TAG", "bu同樣參數"+val+"==="+key);
myparams.append("--" + BOUNDARY + "\r\n");
myparams.append("Content-Disposition: form-data; name=\""+key+"\"\r\n\r\n");
myparams.append(val);
myparams.append("\r\n");
}
}
out.write(myparams.toString().getBytes());
//同樣的參數
if(sameValueName!=null){
//Log.d("TAG", "有同樣參數的提交"+sameValueName);
Iterator iter2 = sameValuNames.entrySet().iterator();
while (iter2.hasNext()) {
Map.Entry entry = (Map.Entry) iter2.next();
String val = entry.getValue().toString();
//Log.d("TAG", "同樣參數"+val);
//String key = entry.getKey().toString();
myparams.append("--" + BOUNDARY + "\r\n");
myparams.append("Content-Disposition: form-data; name=\""+sameValueName+"\"\r\n\r\n");
myparams.append(val);
myparams.append("\r\n");
}
}
out.write(myparams.toString().getBytes());
//上傳上傳名稱不同的圖片
if(imageUrl!=null){
Iterator iter3 = imageUrl.entrySet().iterator();
while (iter3.hasNext()) {
Map.Entry entry = (Map.Entry) iter3.next();
Object val = entry.getValue();
String key = entry.getValue().toString();
File file = new File(val.toString());
StringBuilder sb = new StringBuilder();
sb.append("--");
sb.append(BOUNDARY);
sb.append("\r\n");
sb.append("Content-Disposition: form-data;name=\""+key+"\";filename=\""+ file.getName() + "\"\r\n");
// 這裏不能漏掉，依據文件類型來來做處理。因為上傳的是圖片，所以這裏能夠寫成image/pjpeg
sb.append("Content-Type:image/pjpeg\r\n\r\n");
out.write(sb.toString().getBytes());
DataInputStream in = new DataInputStream(new FileInputStream(
file));
int bytes = 0;
byte[] bufferOut = new byte[1024];
while ((bytes = in.read(bufferOut)) != -1) {
out.write(bufferOut, 0, bytes);
}
out.write("\r\n".getBytes());
in.close();
}
}
//上傳上傳名稱同樣的圖片
Log.d("TAG", "上傳上傳名稱同樣的圖片");
if(sameImageName!=null){
Log.d("TAG", "上傳上傳名稱同樣的圖片"+sameImageName);
Iterator iter4 = sameImageUrlName.entrySet().iterator();
while (iter4.hasNext()) {
Map.Entry entry = (Map.Entry) iter4.next();
Object val = entry.getValue();
Log.d("TAG", "上傳上傳名稱同樣的圖片"+val);
//String key = entry.getValue().toString();
File file = new File(val.toString());
StringBuilder sb = new StringBuilder();
sb.append("--");
sb.append(BOUNDARY);
sb.append("\r\n");
sb.append("Content-Disposition: form-data;name=\""+sameImageName+"\";filename=\""+ file.getName() + "\"\r\n");
// 這裏不能漏掉，依據文件類型來來做處理，因為上傳的是圖片。所以這裏能夠寫成image/pjpeg
sb.append("Content-Type:image/pjpeg\r\n\r\n");
out.write(sb.toString().getBytes());
DataInputStream in = new DataInputStream(new FileInputStream(
file));
int bytes = 0;
byte[] bufferOut = new byte[1024];
while ((bytes = in.read(bufferOut)) != -1) {
out.write(bufferOut, 0, bytes);
}
out.write("\r\n".getBytes());
in.close();
}
}
Log.d("TAG", "上傳完畢數據");
out.write(end_data);
out.flush();
out.close();
// 定義BufferedReader輸入流來讀取URL的響應
BufferedReader reader = null;
reader = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
Log.d("TAG", "返回數據"+reader);
String line = null;
while ((line = reader.readLine()) != null) {
Log.d("TAG", "返回數據。
"+line);
Message msg=new Message();
msg.what=200;
msg.obj=line;
handler.sendMessage(msg);
MyProgressDialog.dismiss();
}
} catch (Exception e) {
Log.d("TAG", "發送POST請求出現異常。" + e);
Message msg=new Message();
msg.what=0;
//msg.obj="無網絡連接";
msg.obj="異常"+e;
handler.sendMessage(msg);
MyProgressDialog.dismiss();
}
return null;
}
@Override
protected void onPostExecute(String result) {
Log.d("TAG", "success");
}
}.execute(myUrl);
}
android.os.NetworkOnMainThreadException