Android：使用OutputStream通过HttpURLConnection发送JSON

我正试图用我的HttpURLConnection发送一个JSON对象。我学习了教程，我不明白为什么我的代码不起作用。HttpURLConnection可以工作，但当我调试程序时，它不包含json

我在这里称之为doInBackground：

public void clickbuttonRecieve(View v) {
    MyAsync performBackgroundTask = new MyAsync();
    performBackgroundTask.execute();
}

这是AsyncTask函数：

 private class MyAsync extends AsyncTask<Void, Void, Void> {
        String LOGIN_URL = "http://bomatec.be/webservice2.php";

        DataOutputStream wr;
        StringBuilder result = new StringBuilder();
        URL url;

        protected Void doInBackground(Void... tmps) {
            HttpURLConnection conn = null;
            try {
                url = new URL(LOGIN_URL);

                conn = (HttpURLConnection) url.openConnection();

                conn.setDoOutput(true); //moved here
                conn.setDoInput(true);
                //conn.connect();

                //conn.setReadTimeout(10000);
                //conn.setConnectTimeout(15000);

                conn.setRequestMethod("POST");


                JSONObject data = new JSONObject();

                data.put("user", "12");
                data.put("lat", "50.8");
                data.put("lng", "4.3");

                String json = data.toString();

                OutputStream wr = conn.getOutputStream();
                OutputStreamWriter osw = new OutputStreamWriter(wr, "UTF-8");
                osw.write(json);
                osw.flush();
                osw.close();

            } catch (IOException e) {
                e.printStackTrace();
                Log.e("MYAPP", e.getMessage(), e);
                return null;
            }catch (JSONException e) {
                Log.e("MYAPP", "unexpected JSON exception", e);
                e.printStackTrace();
                e.printStackTrace();
                Log.e("MYAPP", e.getMessage(), e);
                return null;
            }

            //conn.disconnect();

            return null;



        }


    }

私有类MyAsync扩展了AsyncTask{
字符串登录\u URL=”http://bomatec.be/webservice2.php";
数据输出流；
StringBuilder结果=新建StringBuilder（）；
网址；
受保护的Void doInBackground（Void…tmps）{
HttpURLConnection conn=null；
试一试{
url=新url（登录\ url）；
conn=（HttpURLConnection）url.openConnection（）；
conn.setDoOutput（true）；//搬到这里
conn.setDoInput（真）；
//连接（）；
//连接设置读取超时（10000）；
//连接设置连接超时（15000）；
conn.setRequestMethod（“POST”）；
JSONObject数据=新的JSONObject（）；
数据。put（“用户”、“12”）；
数据。投入（“lat”，“50.8”）；
数据。出售（“液化天然气”，“4.3”）；
字符串json=data.toString（）；
OutputStream wr=conn.getOutputStream（）；
OutputStreamWriter osw=新的OutputStreamWriter（wr，“UTF-8”）；
write（json）；
osw.flush（）；
osw.close（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
Log.e（“MYAPP”，e.getMessage（），e）；
返回null；
}捕获（JSONException e）{
Log.e（“MYAPP”，“意外JSON异常”，e）；
e、 printStackTrace（）；
e、 printStackTrace（）；
Log.e（“MYAPP”，e.getMessage（），e）；
返回null；
}
//连接断开（）；
返回null；
}
}

调试代码时，以下是值：

[IMG]

日志：

12-26 17:27:17.556 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)
12-26 17:27:17.556 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested
12-26 17:27:17.556 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve interface method 18095: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z
12-26 17:27:17.566 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
12-26 17:27:17.566 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode
12-26 17:27:17.566 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve interface method 18099: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;
12-26 17:27:17.566 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
12-26 17:27:18.207 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.view.ViewGroup.onRtlPropertiesChanged, referenced from method android.support.v7.widget.Toolbar.onRtlPropertiesChanged
12-26 17:27:18.207 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve virtual method 17991: Landroid/view/ViewGroup;.onRtlPropertiesChanged (I)V
12-26 17:27:18.207 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x6f at 0x0007
12-26 17:27:18.217 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations
12-26 17:27:18.217 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve virtual method 497: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
12-26 17:27:18.227 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
12-26 17:27:18.227 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType
12-26 17:27:18.227 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve virtual method 519: Landroid/content/res/TypedArray;.getType (I)I
12-26 17:27:18.227 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.widget.LinearLayout$LayoutParams.<init>, referenced from method android.support.design.widget.AppBarLayout$LayoutParams.<init>
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve direct method 18614: Landroid/widget/LinearLayout$LayoutParams;.<init> (Landroid/widget/LinearLayout$LayoutParams;)V
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x70 at 0x0000
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.widget.LinearLayout$LayoutParams.<init>, referenced from method android.support.design.widget.AppBarLayout$LayoutParams.<init>
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve direct method 18614: Landroid/widget/LinearLayout$LayoutParams;.<init> (Landroid/widget/LinearLayout$LayoutParams;)V
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x70 at 0x0000
12-26 17:27:18.797 10192-10194/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: GC_CONCURRENT freed 216K, 12% free 9585K/10887K, paused 16ms+32ms, total 222ms
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.app.Notification$Builder.setLocalOnly, referenced from method com.google.android.gms.common.GooglePlayServicesUtil.zza
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve virtual method 190: Landroid/app/Notification$Builder;.setLocalOnly (Z)Landroid/app/Notification$Builder;
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x6e at 0x00c8
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: DexOpt: access denied from Lcom/google/android/gms/common/GooglePlayServicesUtil; to field Landroid/app/Notification;.extras
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve instance field 16
12-26 17:27:19.358 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x54 at 0x00e7
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven E/dalvikvm: Could not find class 'android.os.UserManager', referenced from method com.google.android.gms.common.GooglePlayServicesUtil.zzah
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve check-cast 230 (Landroid/os/UserManager;) in Lcom/google/android/gms/common/GooglePlayServicesUtil;
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x1f at 0x000c
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven E/dalvikvm: Could not find class 'android.app.AppOpsManager', referenced from method com.google.android.gms.common.GooglePlayServicesUtil.zzb
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve check-cast 25 (Landroid/app/AppOpsManager;) in Lcom/google/android/gms/common/GooglePlayServicesUtil;
12-26 17:27:19.748 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x1f at 0x000e
12-26 17:27:19.878 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm: Could not find method android.content.pm.PackageManager.getPackageInstaller, referenced from method com.google.android.gms.common.GooglePlayServicesUtil.zzj
12-26 17:27:19.878 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven W/dalvikvm: VFY: unable to resolve virtual method 421: Landroid/content/pm/PackageManager;.getPackageInstaller ()Landroid/content/pm/PackageInstaller;
12-26 17:27:19.878 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/dalvikvm: VFY: replacing opcode 0x6e at 0x000b
12-26 17:27:23.872 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/libEGL: loaded /system/lib/egl/libEGL_mali.so
12-26 17:27:23.952 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/libEGL: loaded /system/lib/egl/libGLESv1_CM_mali.so
12-26 17:27:23.952 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/libEGL: loaded /system/lib/egl/libGLESv2_mali.so
12-26 17:27:25.434 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven D/OpenGLRenderer: Enabling debug mode 0
12-26 17:27:25.464 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/Choreographer: Skipped 172 frames!  The application may be doing too much work on its main thread.
12-26 17:27:28.116 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/Choreographer: Skipped 81 frames!  The application may be doing too much work on its main thread.
12-26 17:27:38.867 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err: java.net.ProtocolException: Connection already established
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.net.HttpURLConnection.setRequestMethod(HttpURLConnection.java:666)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at com.example.stevengerrits.bomatec_gerrits_steven.MainActivity$MyAsync.doInBackground(MainActivity.java:222)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at com.example.stevengerrits.bomatec_gerrits_steven.MainActivity$MyAsync.doInBackground(MainActivity.java:197)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at android.os.AsyncTask$2.call(AsyncTask.java:287)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.util.concurrent.FutureTask.run(FutureTask.java:137)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
12-26 17:27:38.917 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
12-26 17:27:38.947 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
12-26 17:27:38.957 10192-10722/com.example.stevengerrits.bomatec_gerrits_steven W/System.err:     at java.lang.Thread.run(Thread.java:856)

12-26 17:27:17.556 10192-10192/com.example.stevengerits.bomatec\u gerrits\u steven W/dalvikvm:VFY:找不到签名中引用的类（Landroid/view/SearchEvent；）
12-26 17:27:17.556 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.view.Window$Callback.onSearchRequested，从方法android.support.v7.view.WindowCallbackWrapper.onSearchRequested引用
12-26 17:27:17.556 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析接口方法18095:Landroid/view/Window$Callback；。onSearchRequested（Landroid/view/SearchEvent；）Z
12-26 17:27:17.566 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：在0x0002处替换操作码0x72
12-26 17:27:17.566 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.view.Window$Callback.OnWindowsStartingActionMode，从方法android.support.v7.view.WindowCallbackWrapper.OnWindowsStartingActionMode引用
12-26 17:27:17.566 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析接口方法18099:Landroid/view/Window$Callback；。OnWindowsStartingActionMode（Landroid/view/ActionMode$回调；I）Landroid/view/ActionMode；
12-26 17:27:17.566 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：在0x0002处替换操作码0x72
12-26 17:27:18.207 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.view.ViewGroup.onRtlPropertiesChanged，从方法android.support.v7.widget.Toolbar.onRtlPropertiesChanged引用
12-26 17:27:18.207 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析虚拟方法17991:Landroid/view/ViewGroup；。不动产变更（一）V
12-26 17:27:18.207 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：在0x0007处替换操作码0x6f
12-26 17:27:18.217 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.content.res.TypedArray.getChangingConfigurations，从方法android.support.v7.widget.TintTypedArray.getChangingConfigurations引用
12-26 17:27:18.217 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析虚拟方法497:Landroid/content/res/TypedArray；。getChangingConfigurations（）I
12-26 17:27:18.227 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：在0x0002处替换操作码0x6e
12-26 17:27:18.227 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.content.res.TypedArray.getType，从方法android.support.v7.widget.TintTypedArray.getType引用
12-26 17:27:18.227 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析虚拟方法519:Landroid/content/res/TypedArray；。getType（I）I
12-26 17:27:18.227 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：在0x0002处替换操作码0x6e
12-26 17:27:18.387 10192-10192/com.example.stevengerrits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.widget.LinearLayout$LayoutParams.，引用自方法android.support.design.widget.AppBarLayout$LayoutParams。
12-26 17:27:18.387 10192-10192/com.example.stevengerits.bomatec_gerrits_steven W/dalvikvm:VFY:无法解析直接方法18614:Landroid/widget/LinearLayout$LayoutParams；。（Landroid/widget/LinearLayout$LayoutParams；）V
12-26 17:27:18.387 10192-10192/com.example.stevengerits.bomatec_gerrits_steven D/dalvikvm:VFY：将操作码0x70替换为0x0000
12-26 17:27:18.387 10192-10192/com.example.stevengerits.bomatec_gerrits_steven I/dalvikvm:找不到方法android.widget.LinearLayout$LayoutParams.，引用自方法android.support.desig