我试图创建一个SIP客户端，参考Android SIP演示。我已经创建了自己的类，但是当我尝试执行它时，我得到空指针异常。源代码是：
package com.example.sipclient;
import java.text.ParseException;
import android.net.sip.SipException;
import android.net.sip.SipManager;
import android.net.sip.SipProfile;
import android.net.sip.SipRegistrationListener;
import android.os.Bundle;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity{
EditText etUsername,etPassword,etIP;
Button bProfileBuilder,bRegisterProfile,bCloseProfile;
Intent intent = new Intent();
PendingIntent pendingIntent = null;
public SipManager mSipManager = null;
public SipProfile mSipProfile = null;
SipProfile.Builder builder = null;
boolean build=false,register=false,close=false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Instantiate SIP Manager
fSipInstantiate();
etUsername = (EditText)findViewById(R.id.username);
etPassword = (EditText)findViewById(R.id.password);
etIP = (EditText)findViewById(R.id.ip);
etUsername.setText("abhinav");
etPassword.setText("abhinav");
etIP.setText("192.168.0.1");
bProfileBuilder = (Button)findViewById(R.id.buildProfile);
bRegisterProfile = (Button)findViewById(R.id.registerProfile);
bCloseProfile = (Button)findViewById(R.id.closeProfile);
bProfileBuilder.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//Build SIP Profile
fSipProfileBuild();
build=true;
}
});
bRegisterProfile.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//Register SIP Profile to server
if(build=true)
{
fSipRegister();
register=true;
close=false;
}
else
genToast("Build Profile First");
}
});
bCloseProfile.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//Close SIP Profile
if(register==true)
{
fSipProfileClose();
close=true;
register=false;
genToast("Profile Closed Successfully");
}
else
genToast("Profile Already Closed");
}
});
}
public void fSipInstantiate(){
if(mSipManager == null){
mSipManager = SipManager.newInstance(this);
genToast("Instantiate Successful");
return;
}
genToast("Instantiate Failed");
return;
}
public void fSipProfileBuild(){
try {
builder = new SipProfile.Builder(etUsername.getText().toString(),etIP.getText().toString());
builder.setPassword(etPassword.getText().toString());
mSipProfile = builder.build();
genToast("Profile Build Successful");
} catch (ParseException e) {
genToast("Profile Build Failed");
e.printStackTrace();
}
fSetIntentFilter();
return;
}
public void fSetIntentFilter(){
//Set Up an Intent filter to recieve calls
try {
intent.setAction("android.SipDemo.INCOMING_CALL");
pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, Intent.FILL_IN_DATA);
mSipManager.open(mSipProfile,pendingIntent,null);
genToast("Intent Filter Set");
}catch (SipException e) {
// TODO Auto-generated catch block
genToast("Intent Filter failed");
e.printStackTrace();
}
return;
}
public void fSipRegister(){
try {
mSipManager.setRegistrationListener(mSipProfile.getUriString(), new SipRegistrationListener() {
@Override
public void onRegistrationFailed(String localProfileUri, int errorCode,
String errorMessage) {
bRegisterProfile.setText("Failed");
}
@Override
public void onRegistrationDone(String localProfileUri, long expiryTime) {
bRegisterProfile.setText("Ready");
}
@Override
public void onRegistering(String localProfileUri) {
bRegisterProfile.setText("Registering");
}
});
} catch (SipException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void fSipProfileClose() {
if (mSipManager == null) {
return;
}
try {
if (mSipProfile != null) {
mSipManager.close(mSipProfile.getUriString());
genToast("Profile Closed Successfully");
bRegisterProfile.setText("Register Profile");
}
} catch (Exception ee) {
genToast("Failed to Close Profile");
}
}
public void genToast(String TText){
Toast toast = Toast.makeText(getApplicationContext(), TText, Toast.LENGTH_SHORT);
toast.show();
return;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
在这里，按下按钮＆＃34; bProfileBuilder＆＃34;，我得到一个空指针异常。当我按下按钮＆＃34; bRegisterProfile＆＃34;时，会发生同样的事情。我似乎无法弄清楚出了什么问题。 StackTrace显示：
08-28 03:28:58.756: W/dalvikvm(21034): threadid=1: thread exiting with uncaught exception (group=0x41b139a8)
08-28 03:28:58.791: E/AndroidRuntime(21034): FATAL EXCEPTION: main
08-28 03:28:58.791: E/AndroidRuntime(21034): java.lang.NullPointerException
08-28 03:28:58.791: E/AndroidRuntime(21034): at com.example.sipclient.MainActivity.fSetIntentFilter(MainActivity.java:127)
08-28 03:28:58.791: E/AndroidRuntime(21034): at com.example.sipclient.MainActivity.fSipProfileBuild(MainActivity.java:118)
08-28 03:28:58.791: E/AndroidRuntime(21034): at com.example.sipclient.MainActivity$1.onClick(MainActivity.java:59)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.view.View.performClick(View.java:4212)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.view.View$PerformClick.run(View.java:17476)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.os.Handler.handleCallback(Handler.java:800)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.os.Handler.dispatchMessage(Handler.java:100)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.os.Looper.loop(Looper.java:194)
08-28 03:28:58.791: E/AndroidRuntime(21034): at android.app.ActivityThread.main(ActivityThread.java:5371)
08-28 03:28:58.791: E/AndroidRuntime(21034): at java.lang.reflect.Method.invokeNative(Native Method)
08-28 03:28:58.791: E/AndroidRuntime(21034): at java.lang.reflect.Method.invoke(Method.java:525)
08-28 03:28:58.791: E/AndroidRuntime(21034): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
08-28 03:28:58.791: E/AndroidRuntime(21034): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
08-28 03:28:58.791: E/AndroidRuntime(21034): at dalvik.system.NativeStart.main(Native Method)
请帮助。
答案 0 :(得分：0)
我觉得这不会导致空指针异常，但是你的寄存器配置文件OnClickListener中有这个。
if(build=true)
{
fSipRegister();
register=true;
close=false;
}
我只是想指出这一点，万一你错过了。
另外，您是否尝试在其他设备上运行应用程序？ mSipManager.open()的第三个参数是监听器，根据android引用（http://developer.android.com/reference/android/net/sip/SipManager.html），它可以被赋予null值。
当我尝试使用SipDemo代码时，我可以在除一个Google Nexus 10.1之外的多个设备上运行它，因为它总是停在该行并告诉我有一个空指针异常。如果你已经在其他设备上试用了你的应用程序，我不确定问题是什么。