android之android.os.NetworkOnMainThreadException错误

android之android.os.NetworkOnMainThreadException异常

使用android测试访问web服务器的webservice时，在MainActivity的主线程中访问webservice，代码如下：

package com.example.myandroidpro;

import java.io.File;

import org.ksoap2.SoapEnvelope;

import org.ksoap2.serialization.SoapObject;

import org.ksoap2.serialization.SoapSerializationEnvelope;

import org.ksoap2.transport.HttpTransportSE;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.os.Bundle;

import android.os.Environment;

import android.os.StrictMode;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity {

    private static String NAMESPACE = "http://service.cxf.test/";

    // webService地址

    private static String URL = "http://192.168.1.119:8080/CxfWebService/services/HelloService/";

    private String method_name = null;

    private Button activity_main_btn1;

    @SuppressLint("NewApi") @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();

        StrictMode.setThreadPolicy(policy);

        

        File rootDirectory = Environment.getRootDirectory();//获取手机根目录

        File storageDirectory = Environment.getExternalStorageDirectory();//获取SD卡根目录

        for(File file : rootDirectory.listFiles()){

            System.err.println(file.isDirectory()+","+file.getName());

        } 

        

        findVIew();

        

        activity_main_btn1.setOnClickListener(new OnClickListener() {

            

            @Override

            public void onClick(View arg0) {

                //发送webservice请求

                    sayHi("zxn");    

            }

        });

        

    }

    private void findVIew() {

        activity_main_btn1 = (Button) findViewById(R.id.activity_main_btn1);

    }

    private String sayHi(String name) {

        String result = null;

        // （1） 指定webservice的命名空间和调用的方法名

        method_name = "sayHi";

        SoapObject soapObj = new SoapObject(NAMESPACE, method_name);

        /**

         * （2） 设置调用方法的参数值，如果没有参数，可以省略。 要注意的是，参数必须和服务声明的@WebParam里面的变量名对应

         */

        soapObj.addProperty("name", name);

        // （3） 生成调用Webservice方法的SOAP请求信息。该信息由SoapSerializationEnvelope对象描述

        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(

                SoapEnvelope.VER11);

        // envelope.bodyOut = rpc;

        envelope.dotNet = false;

        envelope.setOutputSoapObject(soapObj);

        // （4）创建HttpTransportsSE对象。通过AndroidHttpTransport类的构造方法可以指定WebService的WSDL文档的URL

        HttpTransportSE ht = new HttpTransportSE(URL);

        try {

            // (5)使用call方法调用WebService方法

            ht.call(null, envelope);

            // （6）使用getResponse方法获得WebService方法的返回结果

            if (envelope.getResponse() != null) {

                System.out.println(envelope.getResponse());

                result = String.valueOf(envelope.getResponse());

                Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT)

                        .show();

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

        return result;

    }

}

由于在主线程中访问网络，android版本为4.3，导致如下异常：

05-15 02:00:05.769: W/System.err(2269): android.os.NetworkOnMainThreadException

05-15 02:00:05.799: W/System.err(2269):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)

05-15 02:00:05.799: W/System.err(2269):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)

05-15 02:00:05.810: W/System.err(2269):  at libcore.io.IoBridge.connectErrno(IoBridge.java:144)

05-15 02:00:05.810: W/System.err(2269):  at libcore.io.IoBridge.connect(IoBridge.java:112)

05-15 02:00:05.869: D/dalvikvm(2269): GC_FOR_ALLOC freed 345K, 14% free 2674K/3076K, paused 48ms, total 52ms

05-15 02:00:05.869: W/System.err(2269):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)

05-15 02:00:05.880: W/System.err(2269):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)

05-15 02:00:05.880: W/System.err(2269):  at java.net.Socket.connect(Socket.java:842)

05-15 02:00:05.889: W/System.err(2269):  at libcore.net.http.HttpConnection.(HttpConnection.java:76)

05-15 02:00:05.889: W/System.err(2269):  at libcore.net.http.HttpConnection.(HttpConnection.java:50)

05-15 02:00:05.899: W/System.err(2269):  at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)

05-15 02:00:05.899: W/System.err(2269):  at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)

05-15 02:00:05.899: W/System.err(2269):  at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)

05-15 02:00:05.899: W/System.err(2269):  at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)

05-15 02:00:05.899: W/System.err(2269):  at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)

05-15 02:00:05.909: W/System.err(2269):  at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)

05-15 02:00:05.909: W/System.err(2269):  at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)

05-15 02:00:05.909: W/System.err(2269):  at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)

05-15 02:00:05.909: W/System.err(2269):  at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)

05-15 02:00:05.919: W/System.err(2269):  at org.ksoap2.transport.ServiceConnectionSE.openOutputStream(ServiceConnectionSE.java:126)

05-15 02:00:05.919: W/System.err(2269):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:185)

05-15 02:00:05.929: W/System.err(2269):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:118)

05-15 02:00:05.929: W/System.err(2269):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:113)

05-15 02:00:05.969: W/System.err(2269):  at com.example.myandroidpro.MainActivity.sayHi(MainActivity.java:77)

05-15 02:00:05.969: W/System.err(2269):  at com.example.myandroidpro.MainActivity.access$0(MainActivity.java:58)

05-15 02:00:05.969: W/System.err(2269):  at com.example.myandroidpro.MainActivity$1.onClick(MainActivity.java:47)

05-15 02:00:05.969: W/System.err(2269):  at android.view.View.performClick(View.java:4240)

05-15 02:00:05.979: W/System.err(2269):  at android.view.View$PerformClick.run(View.java:17721)

05-15 02:00:05.979: W/System.err(2269):  at android.os.Handler.handleCallback(Handler.java:730)

05-15 02:00:06.012: W/System.err(2269):  at android.os.Handler.dispatchMessage(Handler.java:92)

05-15 02:00:06.012: W/System.err(2269):  at android.os.Looper.loop(Looper.java:137)

05-15 02:00:06.019: W/System.err(2269):  at android.app.ActivityThread.main(ActivityThread.java:5103)

05-15 02:00:06.019: W/System.err(2269):  at java.lang.reflect.Method.invokeNative(Native Method)

05-15 02:00:06.019: W/System.err(2269):  at java.lang.reflect.Method.invoke(Method.java:525)

05-15 02:00:06.034: W/System.err(2269):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)

05-15 02:00:06.034: W/System.err(2269):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)

05-15 02:00:06.039: W/System.err(2269):  at dalvik.system.NativeStart.main(Native Method)

原因：

android.os.NetworkOnMainThreadException是说不要在主线程中访问网络，这个是android3.0版本开始就强制程序不能在主线程中访问网络，要把访问网络放在独立的线程中。

解决：

在开发中，为了防止访问网络阻塞主线程，一般都要把访问网络放在独立线程中或者异步线程AsyncTask中。

 先在AndroidManifest.xml文件manifest节点中添加如下配置：

1、想要忽略这些强制策略问题的话，可以在onCreate()方法里面加上

StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();

StrictMode.setThreadPolicy(policy);

并在方法上加上@SuppressLint("NewApi")，重试，OK。

2、将网络访问放到单独线程中：

package com.example.myandroidpro;

import java.io.File;

import org.ksoap2.SoapEnvelope;

import org.ksoap2.serialization.SoapObject;

import org.ksoap2.serialization.SoapSerializationEnvelope;

import org.ksoap2.transport.HttpTransportSE;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.os.Bundle;

import android.os.Environment;

import android.os.Handler;

import android.os.Looper;

import android.os.Message;

import android.os.StrictMode;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity {

private static String NAMESPACE = "http://service.cxf.test/";

// webService地址

private static String URL = "http://192.168.1.119:8080/CxfWebService/services/HelloService/";

private String method_name = null;

private Button activity_main_btn1;

private int ANDROID_ACCESS_CXF_WEBSERVICES = 001; 

private Handler handler = new Handler(){

@Override

public void handleMessage(Message msg) {

String result = (String) msg.getData().get("result");

String obj = (String) msg.obj;//

activity_main_btn1.setText("请求结果为："+result);

}

};

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        

        File rootDirectory = Environment.getRootDirectory();//获取手机根目录

        File storageDirectory = Environment.getExternalStorageDirectory();//获取SD卡根目录

        for(File file : rootDirectory.listFiles()){

         System.err.println(file.isDirectory()+","+file.getName());

        } 

        

        findVIew();

        

        activity_main_btn1.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View view) {

Thread accessWebServiceThread = new Thread(new WebServiceHandler());

accessWebServiceThread.start();

}

});

        

    }

    class WebServiceHandler implements Runnable{

@Override

public void run() {

Looper.prepare();

String result = sayHi("zxn");

Message message = new Message();

Bundle bundle = new Bundle();

bundle.putString("result", result);

message.what = ANDROID_ACCESS_CXF_WEBSERVICES;//设置消息标示

message.obj = "zxn";

message. setData(bundle);//消息内容

handler.sendMessage(message);//发送消息

Looper.loop();

}

    

    }

    

private void findVIew() {

activity_main_btn1 = (Button) findViewById(R.id.activity_main_btn1);

}

private String sayHi(String name) {

String result = null;

// （1） 指定webservice的命名空间和调用的方法名

method_name = "sayHi";

SoapObject soapObj = new SoapObject(NAMESPACE, method_name);

/**

 * （2） 设置调用方法的参数值，如果没有参数，可以省略。 要注意的是，参数必须和服务声明的@WebParam里面的变量名对应

 */

soapObj.addProperty("name", name);

// （3） 生成调用Webservice方法的SOAP请求信息。该信息由SoapSerializationEnvelope对象描述

SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(

SoapEnvelope.VER11);

// envelope.bodyOut = rpc;

envelope.dotNet = false;

envelope.setOutputSoapObject(soapObj);

// （4）创建HttpTransportsSE对象。通过AndroidHttpTransport类的构造方法可以指定WebService的WSDL文档的URL

HttpTransportSE ht = new HttpTransportSE(URL);

try {

// (5)使用call方法调用WebService方法

ht.call(null, envelope);

// （6）使用getResponse方法获得WebService方法的返回结果

if (envelope.getResponse() != null) {

System.out.println(envelope.getResponse());

result = String.valueOf(envelope.getResponse());

Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT)

.show();

}

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

}

MainActivity的相应布局如下：

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

   

        android:layout_height="fill_parent"

        android:orientation="vertical">

       

            android:id="@+id/activity_main_tv1"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:text="@string/hello_world" />

       

            android:id="@+id/activity_main_btn1"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:text="@string/test_for_cxf_webservice" />

   

3、将网络访问放到异步任务AsyncTask中，代码如下：

package com.example.myandroidpro;

import java.io.File;

import org.ksoap2.SoapEnvelope;

import org.ksoap2.serialization.SoapObject;

import org.ksoap2.serialization.SoapSerializationEnvelope;

import org.ksoap2.transport.HttpTransportSE;

import android.app.Activity;

import android.os.AsyncTask;

import android.os.Bundle;

import android.os.Environment;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class MainActivity extends Activity {

private static String NAMESPACE = "http://service.cxf.test/";

// webService地址

private static String URL = "http://192.168.1.119:8080/CxfWebService/services/HelloService/";

private String method_name = null;

private Button activity_main_btn1;

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        

        File rootDirectory = Environment.getRootDirectory();//获取手机根目录

        File storageDirectory = Environment.getExternalStorageDirectory();//获取SD卡根目录

        for(File file : rootDirectory.listFiles()){

         System.err.println(file.isDirectory()+","+file.getName());

        } 

        

        findVIew();

        

        activity_main_btn1.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View view) {

accessWSAction();

}

private void accessWSAction() {

new AsyncTask() {

//在doInBackground 执行完成后，onPostExecute 方法将被UI 线程调用，

// 后台的计算结果将通过该方法传递到UI 线程，并且在界面上展示给用户.

protected void onPostExecute(Object result) {

super.onPostExecute(result);

activity_main_btn1.setText("请求结果为："+result);//可以更新UI

}

//该方法运行在后台线程中，因此不能在该线程中更新UI，UI线程为主线程

protected Object doInBackground(String... params) {

String result = sayHi("zxn");

// activity_main_btn1.setText("请求结果为："+result);

return result;

}

}.execute();

}

});

    }

private void findVIew() {

activity_main_btn1 = (Button) findViewById(R.id.activity_main_btn1);

}

private String sayHi(String name) {

String result = null;

// （1） 指定webservice的命名空间和调用的方法名

method_name = "sayHi";

SoapObject soapObj = new SoapObject(NAMESPACE, method_name);

/**

 * （2） 设置调用方法的参数值，如果没有参数，可以省略。 要注意的是，参数必须和服务声明的@WebParam里面的变量名对应

 */

soapObj.addProperty("name", name);

// （3） 生成调用Webservice方法的SOAP请求信息。该信息由SoapSerializationEnvelope对象描述

SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(

SoapEnvelope.VER11);

// envelope.bodyOut = rpc;

envelope.dotNet = false;

envelope.setOutputSoapObject(soapObj);

// （4）创建HttpTransportsSE对象。通过AndroidHttpTransport类的构造方法可以指定WebService的WSDL文档的URL

HttpTransportSE ht = new HttpTransportSE(URL);

try {

// (5)使用call方法调用WebService方法

ht.call(null, envelope);

// （6）使用getResponse方法获得WebService方法的返回结果

if (envelope.getResponse() != null) {

System.out.println(envelope.getResponse());

result = String.valueOf(envelope.getResponse());

// Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT)

// .show();

}

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

}