5.0获取当前打开的应用信息

public String getForegroundApp() {
File[] files = new File("/proc").listFiles();
int lowestOomScore = Integer.MAX_VALUE;
String foregroundProcess = null;


for (File file : files) {
if (!file.isDirectory()) {
continue;
}


int pid;
try {
pid = Integer.parseInt(file.getName());
} catch (NumberFormatException e) {
continue;
}


try {
String cgroup = read(String.format("/proc/%d/cgroup", pid));


String[] lines = cgroup.split("\n");


if (lines.length != 2) {
continue;
}


String cpuSubsystem = lines[0];
String cpuaccctSubsystem = lines[1];


if (!cpuaccctSubsystem.endsWith(Integer.toString(pid))) {
// not an application process
continue;
}


if (cpuSubsystem.endsWith("bg_non_interactive")) {
// background policy
continue;
}


String cmdline = read(String.format("/proc/%d/cmdline", pid));
// String cmdline = read(String.format("ps -A |grep pid", pid));


Log.e("cmdline",cmdline);
if (cmdline.contains("com.android.systemui")) {
continue;
}


int uid = Integer.parseInt(
cpuaccctSubsystem.split(":")[2].split("/")[1].replace("uid_", ""));
if (uid >= 1000 && uid <= 1038) {
// system process
continue;
}


int appId = uid - AID_APP;
int userId = 0;
// loop until we get the correct user id.
// 100000 is the offset for each user.
while (appId > AID_USER) {
appId -= AID_USER;
userId++;
}


if (appId < 0) {
continue;
}


// u{user_id}_a{app_id} is used on API 17+ for multiple user account support.
// String uidName = String.format("u%d_a%d", userId, appId);
File oomScoreAdj = new File(String.format("/proc/%d/oom_score_adj", pid));
if (oomScoreAdj.canRead()) {
int oomAdj = Integer.parseInt(read(oomScoreAdj.getAbsolutePath()));
if (oomAdj != 0) {
continue;
}
}
int oomscore = Integer.parseInt(read(String.format("/proc/%d/oom_score", pid)));
if (oomscore < lowestOomScore) {
lowestOomScore = oomscore;
foregroundProcess = cmdline;
}


} catch (Exception e) {
e.printStackTrace();
}
}


return foregroundProcess;
}