java为什么我的应用程序在尝试使用DataOutputStream时崩溃
我正在尝试创建一个应用程序,使用DataOutputStream out=newdataoutputstream(httpURLConnection.getOutputStream())将信息发布到网页; 但如果我这样做,它就会崩溃
我的应用程序/src/main/AndroidManifest。xml如下所示:
<uses-permission 安卓:name="com.symbol.emdk.permission.EMDK"/>
<uses-permission 安卓:name="安卓.permission.ACCESS_NETWORK_STATE" />
<uses-permission 安卓:name="安卓.permission.INTERNET" />
<uses-permission 安卓:name="安卓.permission.BIND_NOTIFICATION_LISTENER_SERVICE" />
<uses-permission 安卓:name="安卓.permission.BIND_CARRIER_MESSAGING_SERVICE" />
<uses-permission 安卓:name="安卓.permission.ACCESS_NOTIFICATION_POLICY" />
<application
安卓:allowBackup="true"
安卓:icon="@mipmap/ic_launcher"
安卓:label="@string/app_name"
安卓:theme="@style/AppTheme" >
<uses-library 安卓:name="com.symbol.emdk"/>
class AsyncT extends AsyncTask<Void,Void,Void>
{
public String info="";
public String info2="";
@Override
protected Void doInBackground(Void... voids) {
try {
URL url = new URL("http://mypage.nu/info.php");
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setDoOutput(true);
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setUseCaches(false);
httpURLConnection.setInstanceFollowRedirects(true);
httpURLConnection.setConnectTimeout(20000);
httpURLConnection.setReadTimeout(30000);
httpURLConnection.setRequestProperty("Content-Type", "application/json");
//httpURLConnection.connect();
try {
DataOutputStream out = new DataOutputStream(httpURLConnection.getOutputStream());//Something goes wrong
}catch(IOException e){
e.printStackTrace();
}
String json="{'name':'test'}";
out.writeBytes("x="+json);
httpURLConnection.disconnect();
}...
我希望我可以检索$obj = json_decode($_POST["x"], false);
但它在试图创建DataOutputStream out = new DataOutputStream
时死亡
# 1 楼答案
你必须告诉连接你想要一个输出流
UrlConnection见第章: Java