我正在尝试学习与Android和php的客户端-服务器通信:
http://androidexample.com/How_To_Make_HTTP_POST_Request_To_Server_-_Android_Example/index.php?view=article_discription&援助= 64,aaid = 89
所以我成功地使应用程序(正是教程中的一个)和php-脚本工作,太(我已经测试了它与chrome扩展"高级休息客户端")。
但是当我运行应用程序并点击按钮发送数据时,TextView中的文本(我将其设置为"hello world"来测试它)消失了,没有其他任何事情发生。TextView保持清晰。
在manifest-file中我包含了
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
在application-tag前。
我现在能做什么?
所以我列出了异常,得到:
10-02 11:56:41.816 13275-13275/? V/Helloagain﹕ android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
at java.net.InetAddress.lookupHostByName(InetAddress.java:410)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:241)
at java.net.InetAddress.getAllByName(InetAddress.java:219)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
at .MainActivity.GetText(MainActivity.java:99)
at .onClick(MainActivity.java:54)
at android.view.View.performClick(View.java:4421)
at android.view.View$PerformClick.run(View.java:17904)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5214)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
at dalvik.system.NativeStart.main(Native Method)
10-02 11:56:41.826 13275-13275/? V/Helloagain﹕ java.lang.NullPointerException
at .MainActivity.GetText(MainActivity.java:134)
at .MainActivity$1.onClick(MainActivity.java:54)
at android.view.View.performClick(View.java:4421)
at android.view.View$PerformClick.run(View.java:17904)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5214)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
at dalvik.system.NativeStart.main(Native Method)
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Android默认不允许在主线程上访问互联网,所以你有两个解决方案:
-
- 创建一个可以访问internet的线程
-
- 在访问互联网之前添加这些行(您可以使用谷歌获取更多信息)
-
StrictMode。ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();StrictMode.setThreadPolicy(政策);