我想过滤一个 logcat
String myCommand="logcat -f /sdcard/output.txt"; //no filters, keep writing
myCommand="logcat -d -f /sdcard/output.txt"; //no filters, just a dump
对我来说很好，但对 mytag 来说不行。
我也在用代码：
String myCommand="logcat myTag *:S"; //the equivalent of logcat -s myTag
myCommand="logcat -s myTag:D";
myCommand="logcat -s myTag:E myTag2:D";
myCommand="logcat myTag:E myTag2:D";
但它返回空文件。
【问题讨论】：
标签： android
try {
File filename = new File(Environment.getExternalStorageDirectory()+"/gphoto4.html");
filename.createNewFile();
String cmd = "logcat -d -f "+filename.getAbsolutePath();
Runtime.getRuntime().exec(cmd);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
也用
String cmd = "logcat -v time -r 100 -f <filename> [TAG]:I [MyApp]:D *:S";
Runtime.getRuntime().exec(cmd);
-v -> Sets the output format for log messages.
-r -> for specifying the size of file.
-f -> file to which you want to write the logs.
[TAG] -> Tag of your application's log.
[MyApp] -> Your application name.
【讨论】：
File filename = new File(Environment.getExternalStorageDirectory()+"/mylog.log");
filename.createNewFile();
String cmd = "logcat -d -f"+filename.getAbsolutePath();
Runtime.getRuntime().exec(cmd);
它对我有用。但对于所有 logcat 输出，不是特殊标签（mytag）。
【讨论】：
public class LogTest extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
Process process = Runtime.getRuntime().exec("logcat -d");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder log=new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
}
TextView tv = (TextView)findViewById(R.id.textView1);
tv.setText(log.toString());
} catch (IOException e) {
}
}
}
你也需要
<uses-permission android:name="android.permission.READ_LOGS" />
引用here
【讨论】：
我创建了一个用于将 logcat 保存到文件的类，请检查：
import android.os.Environment;
import android.util.Log;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
/**
* This singleton class is for debug purposes only. Use it to log your selected classes into file. <br> Needed permissions:
* READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE, READ_LOGS" <br><br>Example usage:<br> <code> FileLogHelper.getInstance().addLogTag(TAG);</code>
* <p/>
* Created by bendaf on 2016-04-28
*/
public class FileLogHelper{
private static final String cmdBegin = "logcat -f ";
private static final boolean shouldLog = true; //TODO: set to false in final version of the app
private static final String TAG = "FileLogHelper";
private String logFileAbsolutePath;
private String cmdEnd = " *:F";
private boolean isLogStarted = false;
private static FileLogHelper mInstance;
private FileLogHelper(){}
public static FileLogHelper getInstance(){
if(mInstance == null){
mInstance = new FileLogHelper();
}
return mInstance;
}
public void initLog(){
if(!isLogStarted && shouldLog){
SimpleDateFormat dF = new SimpleDateFormat("yy-MM-dd_HH_mm''ss", Locale.getDefault());
String fileName = "logcat_" + dF.format(new Date()) + ".txt";
File outputFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/logcat/");
if(outputFile.mkdirs() || outputFile.isDirectory()){
logFileAbsolutePath = outputFile.getAbsolutePath() + "/" + fileName;
startLog();
}
}
}
private void startLog(){
if(shouldLog){
try{
File prevLogFile = new File(logFileAbsolutePath);
prevLogFile.delete();
Runtime.getRuntime().exec(cmdBegin + logFileAbsolutePath + cmdEnd);
isLogStarted = true;
}catch(IOException ignored){
Log.e(TAG, "initLogCat: failed");
}
}
}
/**
* Add a new tag to file log.
*
* @param tag The android {@link Log} tag, which should be logged into the file.
* @param priority The priority which should be logged into the file. Can be V, D, I, W, E, F
*
* @see <a href="http://developer.android.com/tools/debugging/debugging-log.html#filteringOutput">Filtering Log Output</a>
*/
public void addLogTag(String tag, String priority){
String newEntry = " " + tag + ":" + priority;
if(!cmdEnd.contains(newEntry)){
cmdEnd = newEntry + cmdEnd;
if(isLogStarted){
startLog();
}else{
initLog();
}
}
}
/**
* Add a new tag to file log with default priority, which is Verbose.
*
* @param tag The android {@link Log} tag, which should be logged into the file.
*/
public void addLogTag(String tag){
addLogTag(tag, "V");
}
}
例如，在 onCreate() 中调用 FileLogHelper.getInstance().addLogTag(<YOUR_TAG>); 函数，该文件夹将被放置为默认的外部存储，在大多数手机上为 /storage/emulated/0/。
如果您在代码中发现任何错误，请告诉我！
【讨论】：
Dagger is a fully static, compile-time dependency injection framework for both Java and Android. It is an adaptation of an earlier version created by Square and now maintained by Google.
部分手机无法写入外部目录。所以我们必须写入android缓存目录
public static void writeLogToFile(Context context) {
String fileName = "logcat.txt";
File file= new File(context.getExternalCacheDir(),fileName);
if(!file.exists())
file.createNewFile();
String command = "logcat -f "+file.getAbsolutePath();
Runtime.getRuntime().exec(command);
}
上述方法会将所有日志写入文件。另外请在 Manifest 文件中添加以下权限
<uses-permission android:name="android.permission.READ_LOGS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
【讨论】：
public static void printLog()
{
String filename = Environment.getExternalStorageDirectory().getPath() + File.separator + "myandroidapp.log";
String command = "logcat -f "+ filename + " -v time *:V";
try{
Runtime.getRuntime().exec(command);
}
catch(IOException e){
e.printStackTrace();
}
}
【讨论】：