有时候程序出现异常停止，而logcat 的相关信息很快会被冲掉，因而不能够及时的获取异常信息。所以，借鉴别人的代码，写一个工具类，将相关logcat信息及时的保存到文件。
工具类代码:
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.SimpleDateFormat;
import java.util.Date;
public class LogcatFileManager {
private static LogcatFileManager INSTANCE = null;
private static String PATH_LOGCAT;
private LogDumper mLogDumper = null;
private int mPId;
private SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyyMMdd");
private SimpleDateFormat simpleDateFormat2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
public static LogcatFileManager getInstance() {
if (INSTANCE == null) {
INSTANCE = new LogcatFileManager();
}
return INSTANCE;
}
private LogcatFileManager() {
mPId = android.os.Process.myPid();
}
private void setFolderPath(String folderPath) {
File folder = new File(folderPath);
if (!folder.exists()) {
folder.mkdirs();
}
if (!folder.isDirectory())
throw new IllegalArgumentException("The logcat folder path is not a directory: " + folderPath);
PATH_LOGCAT = folderPath.endsWith("/") ? folderPath : folderPath + "/";
}
public void start(String saveDirectoy) {
setFolderPath(saveDirectoy);
if (mLogDumper == null)
mLogDumper = new LogDumper(String.valueOf(mPId), PATH_LOGCAT);
mLogDumper.start();
}
public void stop() {
if (mLogDumper != null) {
mLogDumper.stopLogs();
mLogDumper = null;
}
}
private class LogDumper extends Thread {
private Process logcatProc;
private BufferedReader mReader = null;
private boolean mRunning = true;
String cmds = null;
private String mPID;
private FileOutputStream out = null;
public LogDumper(String pid, String dir) {
mPID = pid;
try {
out = new FileOutputStream(new File(dir, "logcat-" + simpleDateFormat1.format(new Date()) + ".log"), true);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
/**
*
* log level：*:v , *:d , *:w , *:e , *:f , *:s
*
* Show the current mPID process level of E and W log.
*
* */
// cmds = "logcat *:e *:w | grep \"(" + mPID + ")\"";
// cmds = "logcat | grep \"(" + mPID + ")\"";//show log of all level
// cmds = "logcat -s way";//Print label filtering information
cmds = "logcat *:e *:i | grep \"(" + mPID + ")\"";
}
public void stopLogs() {
mRunning = false;
}
@Override
public void run() {
try {
logcatProc = Runtime.getRuntime().exec(cmds);
mReader = new BufferedReader(new InputStreamReader(logcatProc.getInputStream()), 1024);
String line = null;
while (mRunning && (line = mReader.readLine()) != null) {
if (!mRunning) {
break;
}
if (line.length() == 0) {
continue;
}
if (out != null && line.contains(mPID)) {
out.write((simpleDateFormat2.format(new Date()) + " " + line + "\n").getBytes());
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (logcatProc != null) {
logcatProc.destroy();
logcatProc = null;
}
if (mReader != null) {
try {
mReader.close();
mReader = null;
} catch (IOException e) {
e.printStackTrace();
}
}
if (out != null) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
out = null;
}
}
}
}
}
然后在相应的application 或 activity中加入如下代码：
private void startLogcatManager() { String folderPath = null; if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {// save in SD card first folderPath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "BDT-Logcat"; } else {// If the SD card does not exist, save in the directory of application. folderPath = this.getFilesDir().getAbsolutePath() + File.separator + "BDT-Logcat"; } LogcatFileManager.getInstance().start(folderPath); } private void stopLogcatManager() { LogcatFileManager.getInstance().stop(); }
在对应application 或 activity 对应onCreate()方法及onTerminate()调用对应接口，代码如下：
@Override public void onCreate() { super.onCreate(); startLogcatManager(); } @Override public void onTerminate() { stopLogcatManager(); super.onTerminate(); }