Here is the code I use--it truncates the lines at the 4000 limit while also breaking the line at new lines rather than in the middles of the line. Makes for an easier to read log file.
Usage:
Logger.debugEntire("....");
Implementation:
package ...;
import android.util.Log;
import java.util.Arrays;
public class Logger {
private static final String LOG_TAG = "MyRockingApp";
/** @see <a href="http://stackoverflow.com/a/8899735" /> */
private static final int ENTRY_MAX_LEN = 4000;
/**
* @param args If the last argument is an exception than it prints out the stack trace, and there should be no {}
* or %s placeholder for it.
*/
public static void d(String message, Object... args) {
log(Log.DEBUG, false, message, args);
}
/**
* Display the entire message, showing multiple lines if there are over 4000 characters rather than truncating it.
*/
public static void debugEntire(String message, Object... args) {
log(Log.DEBUG, true, message, args);
}
public static void i(String message, Object... args) {
log(Log.INFO, false, message, args);
}
public static void w(String message, Object... args) {
log(Log.WARN, false, message, args);
}
public static void e(String message, Object... args) {
log(Log.ERROR, false, message, args);
}
private static void log(int priority, boolean ignoreLimit, String message, Object... args) {
String print;
if (args != null && args.length > 0 && args[args.length-1] instanceof Throwable) {
Object[] truncated = Arrays.copyOf(args, args.length -1);
Throwable ex = (Throwable) args[args.length-1];
print = formatMessage(message, truncated) + '\n' + android.util.Log.getStackTraceString(ex);
} else {
print = formatMessage(message, args);
}
if (ignoreLimit) {
while (!print.isEmpty()) {
int lastNewLine = print.lastIndexOf('\n', ENTRY_MAX_LEN);
int nextEnd = lastNewLine != -1 ? lastNewLine : Math.min(ENTRY_MAX_LEN, print.length());
String next = print.substring(0, nextEnd /*exclusive*/);
android.util.Log.println(priority, LOG_TAG, next);
if (lastNewLine != -1) {
// Don't print out the \n twice.
print = print.substring(nextEnd+1);
} else {
print = print.substring(nextEnd);
}
}
} else {
android.util.Log.println(priority, LOG_TAG, print);
}
}
private static String formatMessage(String message, Object... args) {
String formatted;
try {
/*
* {} is used by SLF4J so keep it compatible with that as it's easy to forget to use %s when you are
* switching back and forth between server and client code.
*/
formatted = String.format(message.replaceAll("\\{\\}", "%s"), args);
} catch (Exception ex) {
formatted = message + Arrays.toString(args);
}
return formatted;
}
}
