一、首先写一个WifiManage.java主要获取手机内的wifi名和密码
    1.wifi密码一般存储在/data/misc/wifi/wpa_supplicant.conf.想要访问该文件，需要root权限，所以首先我们得获取手机的root权限。
   2.获取终端信息输入输出流：用DataOutputStream和DataInputStream.
   3.往终端输入命令
   4.通过dataInputStream获取命令执行结果，并以UTF-8的编码转换成字符串.
   5.使用正则表达式过滤出wifi的用户名和密码。
     主要的一些代码：
   public List<WifiInfo> WifiRead() {
        List<WifiInfo> wifiInfos=new ArrayList<WifiInfo>();  
        //获取手机root权限
        Process process = null;  
        DataOutputStream dataOutputStream = null;  
        DataInputStream dataInputStream = null;  
        StringBuffer wifiConf = new StringBuffer();
        try{
             //获取手机root权限
            process = Runtime.getRuntime().exec("su");  
            //获得终端信息输入输出流
            dataOutputStream = new DataOutputStream(process.getOutputStream());  
            dataInputStream = new DataInputStream(process.getInputStream());  
            //往终端输入命令
            dataOutputStream  
                    .writeBytes("cat /data/misc/wifi/*.conf\n");  
            dataOutputStream.writeBytes("exit\n");  
            dataOutputStream.flush();
                        //通过dataInputStream获取命令执行结果，并以UTF-8的编码转换成字符串。
            InputStreamReader inputStreamReader = new InputStreamReader(  
                    dataInputStream, "UTF-8");  
            BufferedReader bufferedReader = new BufferedReader(  
                    inputStreamReader);  
            String line = null;  
            while ((line = bufferedReader.readLine()) != null) {  
                wifiConf.append(line);  
            }  
            bufferedReader.close();  
            inputStreamReader.close();  
            process.waitFor();  
                    } catch (Exception e) {  
            throw e;  
        } finally {  
            try {  
                if (dataOutputStream != null) {  
                    dataOutputStream.close();  
                }  
                if (dataInputStream != null) {  
                    dataInputStream.close();  
                }  
                process.destroy();  
            } catch (Exception e) {  
                throw e;  
            }  
        }     
             //使用正则表达式过滤出wifi的用户名和密码。  
        Pattern network = Pattern.compile("network=\\{([^\\}]+)\\}", Pattern.DOTALL);  
        Matcher networkMatcher = network.matcher(wifiConf.toString() );  
        while (networkMatcher.find() ) {  
            String networkBlock = networkMatcher.group();  
            Pattern ssid = Pattern.compile("ssid=\"([^\"]+)\"");  
            Matcher ssidMatcher = ssid.matcher(networkBlock);  
                        if (ssidMatcher.find() ) {     
                WifiInfo wifiInfo=new WifiInfo();  
                wifiInfo.Ssid=ssidMatcher.group(1);  
                Pattern psk = Pattern.compile("psk=\"([^\"]+)\"");  
                Matcher pskMatcher = psk.matcher(networkBlock);  
                if (pskMatcher.find() ) {  
                    wifiInfo.Password=pskMatcher.group(1);  
                } else {  
                    wifiInfo.Password="无密码";  
                }          
                wifiInfos.add(wifiInfo);  
            }  
              
        }  
  
        return wifiInfos;  
}
}
二、建一个WifiInfo类来存放WIFIManage获取的wifi名和密码
三、在主界面将WifiInfo显示出来

原文链接：http://www.apkbus.com/blog-687880-59496.html