Android 之 Wi-Fi通信
阅读前提：本文通信所用的模块是STM32中的EPS8266模块与三星Note3-N9500进行通信。STM32作为客户端，三星Note3-N9500作为服务端，在两者通信的过程中并无借助路由器作为中介者。但需要获取Note3-N9500中所在的IP地址，将IP地址应用到STM32所编写的程序当中
1.在AndroidManifest中添加权限
/**允许程序改变网络状态*/
"android.permission.CHANGE_NETWORK_STATE"/>
/**允许程序改变Wi-Fi的状态*/
"android.permission.CHANGE_WIFI_STATE"/>
/**允许程序获取网络状态信息*/
"android.permission.ACCESS_NETWORK_STATE"/>
/**允许程序访问Wi-Fi网络状态信息*/
"android.permission.ACCESS_WIFI_STATE"/>
/**允许程序唤醒锁定*/
"android.permission.WAKE_LOCK"/>
/**允许程序访问网络*/
"android.permission.INTERNET"/> 2.创建WiFiUtil工具类
import android.content.Context;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.util.Log;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.ServerSocket;
import java.util.List;
public class WiFiUtil {
private String TAG = "WiFiUtil";
private static WiFiUtil INSTANCE;
private WifiManager wifiManager;
private WifiManager.WifiLock wifiLock;
private ServerSocket serverSocket;
private WiFiUtil(Context context){
wifiManager = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
}
public static WiFiUtil getInstance(Context context){
if (INSTANCE == null){
INSTANCE = new WiFiUtil(context);
}
return INSTANCE;
}
/**打开Wi-Fi*/
public void openWiFi(){
if (!wifiManager.isWifiEnabled()){
wifiManager.setWifiEnabled(true);
}
}
/**关闭Wi-Fi*/
public void closeWiFi(){
if (wifiManager.isWifiEnabled()){
wifiManager.setWifiEnabled(false);
}
}
/**检查当前Wi-Fi网卡状态*/
private void checkWiFiState(){
int state = wifiManager.getWifiState();
if (state == WifiManager.WIFI_STATE_DISABLING){
Log.d(TAG,"WIFI_STATE_DISABLED->Wi-Fi网卡不可用");
}else if (state == WifiManager.WIFI_STATE_DISABLED){
Log.d(TAG,"WIFI_STATE_DISABLED->Wi-Fi网卡正在关闭");
}else if (state == WifiManager.WIFI_STATE_ENABLING){
Log.d(TAG,"WIFI_STATE_ENABLING->Wi-Fi网卡正在打开");
}else if (state == WifiManager.WIFI_STATE_ENABLED){
Log.d(TAG,"WIFI_STATE_ENABLED->Wi-Fi网卡可用");
}else if (state == WifiManager.WIFI_STATE_UNKNOWN){
Log.d(TAG,"WIFI_STATE_UNKNOWN->Wi-Fi网卡状态未知");
}
}
/**开始扫描设备周围Wi-Fi热点*/
private void startScan(){
if (wifiManager.startScan()){
Log.d(TAG,"扫描设备周围Wi-Fi热点成功");
}else{
Log.d(TAG,"扫描设备周围Wi-Fi热点失败");
}
}
/**获取设备周围Wi-Fi热点信息*/
private List getWiFiList(){
Log.d(TAG,"获取设备周围Wi-Fi热点信息");
return wifiManager.getScanResults();
}
/**获取当前连接Wi-Fi热点信息*/
private WifiInfo getConnectWiFiInfo(){
/**
*Log.d("获取NetWorkID：",String.valueOf(wifiInfo.getNetworkId()));
*Log.d("获取BSSID：",wifiInfo.getBSSID());
*Log.d("获取SSID：",wifiInfo.getSSID());
*Log.d("获取IP地址：",String.valueOf(wifiInfo.getIpAddress()));
*Log.d("获取Mac地址：",wifiInfo.getMacAddress());
*Log.d("获取连接的速度：",wifiInfo.getSupplicantState().toString());
*Log.d("获取客户端的连通性",wifiInfo.getDetailedStateOf(wifiInfo.getSupplicantState()).toString());
*/
Log.d(TAG,"获取当前连接Wi-Fi热点信息");
return wifiManager.getConnectionInfo();
}
/**获取设备中已保存Wi-Fi热点信息*/
private List getWiFiConfiguration(){
Log.d(TAG,"获取设备中已保存Wi-Fi热点信息");
return wifiManager.getConfiguredNetworks();
}
/**断开当前连接Wi-Fi热点*/
private boolean disconnectWiFi(){
Log.d(TAG,"断开当前连接Wi-Fi热点");
return wifiManager.disconnect();
}
/**连接到指定Wi-Fi热点*/
private boolean connectDefaultWiFi(int defaultNetWorkID){
Log.d(TAG,"连接到指定Wi-Fi热点");
return wifiManager.enableNetwork(defaultNetWorkID,true);
}
/**创建Wi-Fi锁*/
private void createdWiFiLock(){
wifiLock = wifiManager.createWifiLock(WifiManager.WIFI_MODE_FULL_HIGH_PERF,"SCM-CONNECTION");
Log.d(TAG,"创建Wi-Fi锁");
}
/**锁定当前连接Wi-Fi热点*/
private void lockConnectWiFi(){
wifiLock.acquire();
Log.d(TAG,"锁定当前Wi-Fi热点");
}
/**解锁当前连接Wi-Fi热点*/
private void unlockConnectWiFi(){
if (wifiLock.isHeld()){
wifiLock.release();
}
Log.d(TAG,"解锁当前连接Wi-Fi热点");
}
/**设备开启Wi-Fi热点*/
public void createdWiFiHotspots(String SSID,String PASSWORD){
closeWiFi();
/**设置WiFiConfiguration参数*/
WifiConfiguration wifiConfiguration = new WifiConfiguration();
/**Wi-Fi热点名称*/
wifiConfiguration.SSID = SSID;
/**Wi-Fi热点连接密码*/
wifiConfiguration.preSharedKey = PASSWORD;
/**Wi-Fi热点是否隐藏*/
wifiConfiguration.hiddenSSID = false ;
/**Wi-Fi热点配置是否启用*/
wifiConfiguration.status = WifiConfiguration.Status.ENABLED;
/**IEEE 802.11认证算法 OPEN*/
wifiConfiguration.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
/**组秘钥TKIP+CCMP*/
wifiConfiguration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
wifiConfiguration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
/**秘钥管理WPA_PSK*/
wifiConfiguration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
/**对称秘钥TKIP+CCMP*/
wifiConfiguration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
wifiConfiguration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
try {
Method Enable_Method = wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, Boolean.TYPE);
boolean status = (Boolean) Enable_Method.invoke(wifiManager, wifiConfiguration, true);
if (status) {
Log.d(TAG,"SSID："+SSID);
Log.d(TAG,"PASSWORD："+PASSWORD);
} else {
Log.d(TAG,"设备热点创建失败");
}
} catch (Exception e) {
e.printStackTrace();
Log.d(TAG,"设备热点创建失败");
}
receiveDataFromSCM();
}
/**设备关闭Wi-Fi热点*/
public void closedWiFiHotspots() {
try {
Method AP_Method = wifiManager.getClass().getMethod("getWifiApConfiguration");
AP_Method.setAccessible(true);
WifiConfiguration wifiConfiguration = (WifiConfiguration) AP_Method.invoke(wifiManager);
Method Enable_Method = wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
Enable_Method.invoke(wifiManager, wifiConfiguration, false);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
/**判断当前Wi-Fi热点是否为默认的Wi-Fi热点*/
public void discriminationConnectWiFi(int defaultNetWorkID){
WifiInfo wifiInfo = getConnectWiFiInfo();
/**当前连接的NetWorkID*/
int NetWorkID = wifiInfo.getNetworkId();
/**当前Wi-Fi热点是否为指定Wi-Fi热点
* true->对当前Wi-Fi热点进行锁定
* false->对当前Wi-Fi热点进行断开，重新连接到指定Wi-Fi热点并且锁定
* */
if (defaultNetWorkID == NetWorkID){
Log.d(TAG,"当前Wi-Fi是默认Wi-Fi");
createdWiFiLock();
lockConnectWiFi();
}else {
if (disconnectWiFi()){
Log.d(TAG,"断开当前Wi-Fi连接成功");
if (connectDefaultWiFi(defaultNetWorkID)){
Log.d(TAG,"连接到指定Wi-Fi成功");
createdWiFiLock();
lockConnectWiFi();
}else {
Log.d(TAG,"连接到指定Wi-Fi失败");
}
}else {
Log.d(TAG,"断开当前Wi-Fi连接失败");
}
}
}
/**Logcat设备中所有保留的Wi-Fi热点信息*/
public void logoutAllWifiConfiguration(){
final List wifiConfigurationList = getWiFiConfiguration();
WifiConfiguration item;
final int SIZE = wifiConfigurationList.size();
for (int i=0 ; i"NetWorkID："+String.valueOf(item.networkId));
Log.d(TAG,"Statue："+String.valueOf(item.status));
Log.d(TAG,"SSID："+item.SSID);
if (item.BSSID == null) {
Log.d(TAG, "BSSID：null" );
}else {
Log.d(TAG,"BSSID："+item.BSSID);
}
Log.d(TAG,">>>>>>>>>>>>>>>>>>>>");
}
}
/**创建Client端Socket*/
/**创建Server端Socket*/
private void receiveDataFromSCM() {
new Thread(new ReceiveSCMDataRun(8080)).start();
} 3.创建ReceiveSCMDataRun方法类
import android.util.Log;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class ReceiveSCMDataRun implements Runnable{
private ServerSocket serverSocket;
private Socket socket;
public ReceiveSCMDataRun(int PORT){
try{
serverSocket = new ServerSocket(PORT);
}catch (IOException e){
e.printStackTrace();
}
}
@Override
public void run(){
try {
Log.d("socket","正在等待客户端的连接");
socket = serverSocket.accept();
Log.d("socket","连接成功");
}catch (IOException e){
e.printStackTrace();
}
/*一般情况下是每获取一个socket的入站连接，打开一个输入流，但Android服务端程序与单片机连接为一一对应关系，所以Android只接受一个客户端的入站连接*/
while (true){
try {
/*获取客户端的输入流*/
InputStream inputStream = socket.getInputStream();
/*size用于检测inputStream中的是否有可读取的数据流*/
int size = inputStream.available();
/*temp存储读取一个字节*/
byte[] temp = new byte[1];
if (size != 0){
/*read(byte[] b[])方法会返回一个整型*/
inputStream.read(temp);
String HEXString = bytesToHexString(temp);
/*打印输出获取的数据*/
Log.d("HEXString",HEXString);
/*手动清空temp中的数据，避免占用内存*/
temp = null;
}
}catch (IOException e){
e.printStackTrace();
}catch (NullPointerException e){
e.printStackTrace();
}
}
}
/**将输入的byte数组转换为16进制的字符串*/
private String bytesToHexString(byte[] bytes){
String HEXString = "";
for (int i = 0;i < bytes.length; i++) {
String hex = Integer.toHexString(bytes[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
HEXString += hex.toUpperCase();
}
return HEXString;
}
}