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);
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：
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;
}
}