首先简单介绍一下sip协议，sip是会话启动协议，主要用于网络多媒体通话。必须是android2.3或其以上版本才可以调用Sip api，并且设备必须支持sip才可以进行sip通话。

SIP使用的api主要放在android.net.sip中，其中最核心的类为SipManager.java，关系图如下所示：

本地的SipProfile存放在一个xml文件中，主要用于保存sip的username,domain和password，SharedPreference配置文件如下所示：

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"><EditTextPreferenceandroid:name="SIP Username"android:summary="Username for your SIP Account"android:defaultValue=""android:title="Enter Username"android:key="namePref" /><EditTextPreferenceandroid:name="SIP Domain"android:summary="Domain for your SIP Account"android:defaultValue=""android:title="Enter Domain"android:key="domainPref" /><EditTextPreferenceandroid:name="SIP Password"android:summary="Password for your SIP Account"android:defaultValue=""android:title="Enter Password"android:key="passPref"android:password="true" />
</PreferenceScreen>

更新SharedPreference的代码如下：

public void updatePreferences() {Intent settingsActivity = new Intent(getBaseContext(),SipSettings.class);startActivity(settingsActivity);}

调用updatePreferences()方法会有如下的效果图显示：

通过此界面可以修改本地的SipProfile帐号信息。

接打电话时需要更新对方SipProfile的信息，代码如下：

/*** Updates the status box at the top of the UI with a messege of your choice.* @param status The String to display in the status box.*/public void updateStatus(final String status) {// Be a good citizen.  Make sure UI changes fire on the UI thread.this.runOnUiThread(new Runnable() {public void run() {TextView labelView = (TextView) findViewById(R.id.sipLabel);labelView.setText(status);}});}/*** Updates the status box with the SIP address of the current call.* @param call The current, active call.*/public void updateStatus(SipAudioCall call) {String useName = call.getPeerProfile().getDisplayName();if(useName == null) {useName = call.getPeerProfile().getUserName();}updateStatus(useName + "@" + call.getPeerProfile().getSipDomain());}

拨电话代码如下：

/*** Make an outgoing call.*/public void initiateCall() {updateStatus(sipAddress);try {SipAudioCall.Listener listener = new SipAudioCall.Listener() {// Much of the client's interaction with the SIP Stack will// happen via listeners.  Even making an outgoing call, don't// forget to set up a listener to set things up once the call is established.@Overridepublic void onCallEstablished(SipAudioCall call) {call.startAudio();call.setSpeakerMode(true);call.toggleMute();updateStatus(call);}@Overridepublic void onCallEnded(SipAudioCall call) {updateStatus("Ready.");}};call = manager.makeAudioCall(me.getUriString(), sipAddress, listener, 30);}catch (Exception e) {Log.i("WalkieTalkieActivity/InitiateCall", "Error when trying to close manager.", e);if (me != null) {try {manager.close(me.getUriString());} catch (Exception ee) {Log.i("WalkieTalkieActivity/InitiateCall","Error when trying to close manager.", ee);ee.printStackTrace();}}if (call != null) {call.close();}}}

接电话代码如下：

// Set up the intent filter.  This will be used to fire an// IncomingCallReceiver when someone calls the SIP address used by this// application.IntentFilter filter = new IntentFilter();filter.addAction("android.SipDemo.INCOMING_CALL");callReceiver = new IncomingCallReceiver();this.registerReceiver(callReceiver, filter);

package com.example.android.sip;import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.sip.*;/*** Listens for incoming SIP calls, intercepts and hands them off to WalkieTalkieActivity.*/
public class IncomingCallReceiver extends BroadcastReceiver {/*** Processes the incoming call, answers it, and hands it over to the* WalkieTalkieActivity.* @param context The context under which the receiver is running.* @param intent The intent being received.*/@Overridepublic void onReceive(Context context, Intent intent) {System.out.println("IncomingCallReceiver::::::");SipAudioCall incomingCall = null;try {SipAudioCall.Listener listener = new SipAudioCall.Listener() {@Overridepublic void onRinging(SipAudioCall call, SipProfile caller) {try {call.answerCall(30);} catch (Exception e) {e.printStackTrace();}}};WalkieTalkieActivity wtActivity = (WalkieTalkieActivity) context;incomingCall = wtActivity.manager.takeAudioCall(intent, listener);incomingCall.answerCall(30);incomingCall.startAudio();incomingCall.setSpeakerMode(true);if(incomingCall.isMuted()) {incomingCall.toggleMute();}wtActivity.call = incomingCall;wtActivity.updateStatus(incomingCall);} catch (Exception e) {if (incomingCall != null) {incomingCall.close();}}}
}

设置本地sip:

/*** Handles SIP authentication settings for the Walkie Talkie app.*/
public class SipSettings extends PreferenceActivity {@Overridepublic void onCreate(Bundle savedInstanceState) {// Note that none of the preferences are actually defined here.// They're all in the XML file res/xml/preferences.xml.super.onCreate(savedInstanceState);addPreferencesFromResource(R.xml.preferences);System.out.println("SipSettings::::::::::");}
}