Android CPU监控想法，思路，核心技术和代码
核心算法描述：
第一步：获取正在运行的进程， 保存在集合当中 ： List<IsRunningAppInfo> appList
第二步：读取总使用的CPU， 路径在 private static String path = "/proc/stat";
第三步：读取所有运行进程CPU，路径在 "/proc/" + pid + "/stat"; //pid为进程号
第四步：读取所有运行线程CPU，路径在 "/proc/" + pid + "/task" + tid +"/stat"; //pid为进程号，tid为线程号
第五步：读取好文件的信息，分别保存在不同集合当中，然后回调回去，存入数据库（根据需求，可灵活运用），避免一边读取文件，一边保存数据库当中，不然将耗费大量的时间，产生的误差特别的大
第六步：数据的内容保存好后，到另外一个activity中，从数据库中读取数据，并列表显示出数据。注意：读取的时候，可能会碰到读取文件的内容的时候，还没有读好（算所占比例的时候会出现出现“除数为0”），需要定义一个handle，在handle当中读取数据（读的过程中，判断是否数据存储完毕），并显示读取的数据，不能在activity当中不然会出现“AndroidRunTime”错误。
获取正在运行的进程：
/** * 获取正在运行的进程 * * @return */public List<IsRunningAppInfo> queryRunningApp() {List<IsRunningAppInfo> listRunApp = new ArrayList<IsRunningAppInfo>();am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);List<RunningAppProcessInfo> list = am.getRunningAppProcesses();RunningAppProcessInfo runningPro = null;IsRunningAppInfo appInfo = null;for (int i = 0; i < list.size(); i++) {runningPro = list.get(i);appInfo = new IsRunningAppInfo();appInfo.setPid(runningPro.pid);appInfo.setProcessName(runningPro.processName);appInfo.setUid(runningPro.uid);pkgManager(appInfo);listRunApp.add(appInfo);}return listRunApp;}/** * 获取应用程序的 程序名，图标 * * @param appInfo * @throws NameNotFoundException */public void pkgManager(IsRunningAppInfo appInfo) {try {PackageManager pm = context.getPackageManager();PackageInfo pkInfo;pkInfo = pm.getPackageInfo(appInfo.getProcessName(), 0);appInfo.setIcon(pkInfo.applicationInfo.loadIcon(pm));appInfo.setAppName(pkInfo.applicationInfo.loadLabel(pm).toString());} catch (NameNotFoundException e) {e.printStackTrace();}}读取CPU文件：public void cpuMain() {sqliteHelp.clearAllTableData(new String[] {Config.TBL_CPUMONITOR_PROCESSCPU,Config.TBL_CPUMONITOR_TheadCPU,Config.TBL_CPUMONITOR_TOTALCPU }); // 在读取文件前清空所有表数据R_W_File rw = new R_W_File();rw.clearFileData(new File(rw.getSdcardPath(), "result.txt"));i = 0;while (i < 2) {queryRunningApp(); // 获取正在运行的应用程序信息if (i == 0) {readTotalCPU(i); // 捕捉时，总CPU}readProcessCPU(i); // 进程CPU--->线程CPUreadThreadCPU(i);i++;}}/** * 获取正在运行的应用程序 */protected void queryRunningApp() {IsRunningAppProgress pro = new IsRunningAppProgress(context);appList = pro.queryRunningApp();}/** * 总CPU使用量 */protected void readTotalCPU(int i) {AsyncTask_TotalCPU taskTotalCPU = new AsyncTask_TotalCPU(context);taskTotalCPU.execute(i, null, null);}/** * 进程CPU */protected void readProcessCPU(int i) {AsyncTask_ProgressCPU taskProcessCPU = null;taskProcessCPU = new AsyncTask_ProgressCPU(new ProcessCallback(),appList);taskProcessCPU.execute(i, null, null);}/** * 线程CPU */protected void readThreadCPU(int i) {AsyncTask_TheadCPU taskThreadCPU = new AsyncTask_TheadCPU(new ThreadCallback(), appList);taskThreadCPU.execute(i, null, null);}/** * 回调方法 */class ThreadCallback implements ICallbacks {@Overridepublic <T> void call(T t1, T t2) {if ((Integer) t2 == 1) {readTotalCPU(1); // 捕捉时，总CPU}@SuppressWarnings("unchecked")Map<String[], IsRunningAppInfo> saveThreadCPUMap = (Map<String[], IsRunningAppInfo>) t1;saveThreadData(saveThreadCPUMap, (Integer) t2);}}/** * 回调方法 */class ProcessCallback implements ICallbacks {@Overridepublic <T> void call(T t1, T t2) {@SuppressWarnings("unchecked")Map<String[], IsRunningAppInfo> saveProCPUMap = (Map<String[], IsRunningAppInfo>) t1;saveProData(saveProCPUMap, (Integer) t2);}}public void saveThreadData(Map<String[], IsRunningAppInfo> saveThreadCPUMap, int j) {Set<String[]> key = saveThreadCPUMap.keySet();Iterator<String[]> it = key.iterator();String[] str = null;IsRunningAppInfo appInfo = null;ContentValues cv = null;while (it.hasNext()) {str = it.next();appInfo = saveThreadCPUMap.get(str);cv = new ContentValues();cv.put("processName", appInfo.getProcessName());cv.put("pid", appInfo.getPid());cv.put("tid", Long.valueOf(str[0]));cv.put("utime", Long.valueOf(str[13]));cv.put("stime", Long.valueOf(str[14]));cv.put("numTimes", j);sqliteHelp.append(Config.TBL_CPUMONITOR_TheadCPU, cv);}if (j == 1) {writeData();}}/** * 保存进程数据 * * @param saveProCPUMap * @param j */private void saveProData(Map<String[], IsRunningAppInfo> saveProCPUMap,int j) {Set<String[]> key = saveProCPUMap.keySet();Iterator<String[]> it = key.iterator();String[] str = null;IsRunningAppInfo runApp = null;ContentValues cv = null;while (it.hasNext()) {str = it.next();runApp = saveProCPUMap.get(str);cv = new ContentValues();if (runApp.getIcon() == null) {cv.put("icon",FormatImage.getInstace().getDrawableToByte(context.getResources().getDrawable(R.drawable.ic_launcher_default)));} elsecv.put("icon",FormatImage.getInstace().getDrawableToByte(runApp.getIcon()));if (runApp.getAppName() == null || runApp.getAppName().equals("")) {cv.put("appName", runApp.getProcessName());} elsecv.put("appName", runApp.getAppName());cv.put("processName", runApp.getProcessName());cv.put("pid", runApp.getPid());cv.put("utime", str[13]);cv.put("stime", str[14]);cv.put("cutime", str[15]);cv.put("cstime", str[16]);cv.put("numTimes", j);sqliteHelp.append(Config.TBL_CPUMONITOR_PROCESSCPU, cv);}if (j == 1) {writeData();}}public void writeData() {try {R_W_File files = new R_W_File();File mFile = new File(files.getSdcardPath(), "result.txt");files.writeFileDataAtTail(mFile, "1");} catch (IOException e) {e.printStackTrace();}}}显示CPU列表数据：public View getView(int position, View convertView, ViewGroup parent) {ProcessCPU pro = list.get(position);if (convertView == null) {convertView = inflater.inflate(layoutId, null);appView = new AppView(convertView);convertView.setTag(appView);} else {appView = (AppView) convertView.getTag();}appView.pkgName.setText(pro.getProcessName());appView.appIcon.setBackgroundDrawable(pro.getIcon()); // 图标appView.appName.setText(pro.getAppName()); // 应用名appView.pb.setMax(100);if (pro.getProcessName().equals("system"))Log.e("systemValue:" + pro.getUtime() + " ==totalCPU:" + totalCPU);double schedule = Double.valueOf(String.format("%.2f", pro.getUtime()* 100.00 / totalCPU));appView.pb.setProgress((int) schedule);appView.tvPb.setText("" + schedule + "%");return convertView;}handle中读取并显示数据：@Overridepublic void handleMessage(Message msg) {super.handleMessage(msg);dialog = (Dialog) msg.obj;queryTotalCPU();queryProcessList();if (adapterCpuChart == null) {adapterCpuChart = new Adapter_cpu_chart(context,R.layout.adapter_cpu_chart, list, totalCPU);}lvChart.setAdapter(adapterCpuChart);adapterCpuChart.notifyDataSetChanged();pbBar.closeDialogProgressBar(dialog);}/** * 查找总共CPU时间片 每次进行数据查询的时候，将表中的数据重新请空 */public void queryTotalCPU() {sql = "select (max(num1)-min(num1)) as total from "+ "(select (t.user+t.nice+t.system+t.iowait+t.irq+t.softirq+t.stealstolen+t.guest) as num1 "+ "from TotalCPU t)";cursor = sqliteHelp.query(sql);int index = -1;long allValue = -1;long ownValue = -1;long ownThreadCPU = -1;if (cursor.moveToFirst()) {index = cursor.getColumnIndex("total");allValue = cursor.getLong(index);}sqliteHelp.closeDb();sql = "select (max(num2)-min(num2)) as ownCPU from (select (p.utime+p.stime+p.cstime+p.cutime) as num2 "+ "from ProcessCPU p "+ "where p.processName='"+ pkgName+ "') ";cursor = sqliteHelp.query(sql);if (cursor.moveToFirst()) {index = cursor.getColumnIndex("ownCPU");ownValue = cursor.getLong(index);}sqliteHelp.closeDb();sql = "select max(num3)-min(num3) as ownThreadCPU "+ "from (select (t.utime+t.stime) as num3 "+ "from ThreadCPU t " + "where t.processName='" + pkgName+ "') ";cursor = sqliteHelp.query(sql);if (cursor.moveToFirst()) {index = cursor.getColumnIndex("ownThreadCPU");ownThreadCPU = cursor.getLong(index);}sqliteHelp.closeDb();totalCPU = (allValue - ownValue - ownThreadCPU);Log.e("allValue:" + allValue + " " + " ownValue:" + ownValue+ " ownThreadCPU" + ownThreadCPU);}/** * 查找所有进程的CPU时间片 */public void queryProcessList() {sql = "select p.processName,p.appName,p.icon,sum(temp.utime) as utime "+ "from (select processName,(max(utime)-min(utime)) as utime "+ "from (select processName,appName,icon, (utime+stime+cutime+cstime) as utime "+ "from ProcessCPU where processName <> '"+ pkgName+ "' and numTimes=0 "+ "union all "+ "select processName,appName,icon, (utime+stime+cutime+cstime) as utime "+ "from ProcessCPU where processName <> '"+ pkgName+ "' and numTimes=1 ) "+ "group by processName "+ "union all select processName,(max(utime)-min(utime)) as utime "+ "from (select processName, sum(utime+stime) as utime "+ "from ThreadCPU where processName <> '"+ pkgName+ "' and numTimes=0 "+ "group by processName union all select processName, sum(utime+stime) as utime "+ "from ThreadCPU where processName <> '"+ pkgName+ "' and numTimes=1 "+ "group by processName) group by processName) as temp,ProcessCPU p "+ "where p.processName=temp.processName group by p.processName "+ "order by utime desc limit 10";list = new ArrayList<ProcessCPU>();cursor = sqliteHelp.query(sql);ProcessCPU proCPU = null;if (cursor.moveToFirst()) {do {proCPU = new ProcessCPU();int processName = cursor.getColumnIndex("processName");int appName = cursor.getColumnIndex("appName");int icon = cursor.getColumnIndex("icon");int utime = cursor.getColumnIndex("utime");proCPU.setAppName(cursor.getString(appName));proCPU.setProcessName(cursor.getString(processName));proCPU.setIcon(FormatImage.getInstace().getByteToDrawable(cursor.getBlob(icon)));proCPU.setUtime(cursor.getLong(utime));list.add(proCPU);} while (cursor.moveToNext());}sqliteHelp.closeDb();}读取进程CPU：public void readFile() {String[] str = null;for (int i = 0; i < list.size(); i++) {runApp = list.get(i);file = new File(getPath(runApp.getPid()));try {fis = new FileInputStream(file);br = new BufferedReader(new InputStreamReader(fis));String readLine;while ((readLine = br.readLine()) != null) {str = readLine.split(" ");}br.close();fis.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}saveProCPUMap.put(str, runApp);}}/** * 获取每个进程的 文件路径 * * @param pid * @return */public String getPath(long pid) {return "/proc/" + pid + "/stat";}读取线程CPU：public void queryThreadCPU(List<IsRunningAppInfo> list) throws IOException {for (int i = 0; i < list.size(); i++) {IsRunningAppInfo appInfo = list.get(i);queryThreadCPU(appInfo);}}/** * 根据每一个pid获取CPU使用率 * * @param pid * @return * @throws IOException */public void queryThreadCPU(IsRunningAppInfo appInfo) throws IOException {path = "/proc/" + appInfo.getPid() + "/task";file = new File(path);if (file.exists() && file != null) {files = file.listFiles();if (files != null) {queryThreadCPU(files, appInfo);}}}/** * 查询某一个进程的 线程CPU使用情况 * * @param files * @return * @throws IOException */private void queryThreadCPU(File[] files, IsRunningAppInfo appInfo)throws IOException {String readLine;String[] tStr = null;for (int i = 0; i < files.length; i++) {File f = files[i];path = f.getPath() + "/stat";file = new File(path);fis = new FileInputStream(file);br = new BufferedReader(new InputStreamReader(fis));while ((readLine = br.readLine()) != null) {tStr = readLine.split(" ");}}saveThreadCPUMap.put(tStr, appInfo);}@Overrideprotected void onPostExecute(Void result) {super.onPostExecute(result);}读取总CPU：public Long readFile() {String[] str = null;file = new File(path);try {fis = new FileInputStream(file);br = new BufferedReader(new InputStreamReader(fis));String readLine;if ((readLine = br.readLine()) != null) {str = readLine.split(" ");}br.close();fis.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return changeArray(str);}private Long changeArray(String[] str) {Log.e("长度：" + str.length);ContentValues cv = new ContentValues();cv.put("user", Long.valueOf(str[2]));cv.put("nice", Long.valueOf(str[3]));cv.put("system", Long.valueOf(str[4]));cv.put("idle", Long.valueOf(str[5]));cv.put("iowait", Long.valueOf(str[6]));cv.put("irq", Long.valueOf(str[7]));cv.put("softirq", Long.valueOf(str[8]));cv.put("stealstolen", Long.valueOf(str[9]));cv.put("guest", Long.valueOf(str[10]));cv.put("numTimes", i);return sqliteHelp.append(Config.TBL_CPUMONITOR_TOTALCPU, cv);}