Anroid 工具类 —— 日志

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

//这个类可以让maven根据dev或prod自动生成，里面只有一个isDebugEnabled变量
import com.newland.mtype.common.RunningModel;

import android.content.Context;
import android.content.Intent;
import android.os.Environment;
import android.util.Log;

/**
 * 日志工厂

 */
public class DeviceLoggerFactory {
	
	enum Level {
		Debug,
		Info,
		Warn,
		Error
	}
	
	public static final byte NONE = 0x00;
	public static final byte CONSOLE = 0x01;
	public static final byte BROADCAST = 0x02;
	public static final byte FILE = 0x04;
	public static final byte ALL = (byte) 0xFF;
	
	public static final String ACTION_LOG = "LOG";
	public static final String EXTRA_LEVEL = "LEVEL";
	public static final String EXTRA_TAG = "TAG";
	public static final String EXTRA_MSG = "MSG";
	
	private static final SimpleDateFormat SDF_DATE = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss", Locale.getDefault());
	private static final SimpleDateFormat SDF_TIME = new SimpleDateFormat("hh:mm:ss.SSS", Locale.getDefault());
	
	private static Context context;
	private static byte logType = CONSOLE;
	
	private static File file = null;
	
	public static void init(Context context, byte logType) {
		DeviceLoggerFactory.context = context;
		DeviceLoggerFactory.logType = logType;
	}
	
	private static void initFile() {
		//这里的path无论有没有申明权限都能拿到，通常值为 "/storage/emulated/0"
		if(file != null && file.exists()) return;
		String sdPath = Environment.getExternalStorageDirectory().getAbsolutePath();
		String logDir = sdPath + "/newland/log/";
		String fileName = SDF_DATE.format(new Date()) + ".txt";
		File dir = new File(logDir);
		//当路径不存在时，必须调用mkdirs主动创建，BufferedWriter和OutputStreamWriter都不会帮我们创建目录
		if(!dir.exists()) {
			dir.mkdirs();
		}
		file = new File(logDir + fileName);
		if(!file.exists()) {
			try {
				file.createNewFile();
			} catch (IOException e) {
				e.printStackTrace();
				file = null;
			}
		}
	}
	
	public static DeviceLogger getLogger(final String tag) {
		return new DeviceLogger() {
			
			private void recordLog(Level level, String msg) {
				//debug的日志只有在允许打印时，才会打印。其它日志是无论什么情况都打印
				if(logType == NONE) return;
				if(RunningModel.isDebugEnabled && level == Level.Debug || level != Level.Debug) {
					if((logType & BROADCAST) != 0 && context != null) {
						Intent intent = new Intent(ACTION_LOG);
						//由于extra只能存放一些基本变量，因此需要将枚举类转为string
						intent.putExtra(EXTRA_LEVEL, level.toString());
						intent.putExtra(EXTRA_TAG, tag);
						intent.putExtra(EXTRA_MSG, msg);
						context.sendBroadcast(intent);
					}
					if((logType & FILE) != 0) {
						initFile();
						if(file != null) {
							try {
								//FileOutputStream的第二个参数表示是否append（如果文件存在，是追加还是清空重写）
								BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true)));
								bw.write(level + " " + SDF_TIME.format(new Date()) + " " + tag + " " + msg + "\r\n");
								//close方法自带flush，所以前面就不用多此一举的去flush了
								bw.close();
							} catch (FileNotFoundException e) {
								e.printStackTrace();
							} catch (IOException e) {
								e.printStackTrace();
							}
						}
					}
					if((logType & CONSOLE) != 0) {
						switch(level) {
						case Debug:
							Log.d(tag, msg);
							break;
						case Info:
							Log.i(tag, msg);
							break;
						case Warn:
							Log.w(tag, msg);
							break;
						case Error:
							Log.e(tag, msg);
							break;
						}
					}
				}
			}
			
			private void recordLog(Level level, String msg, Throwable e) {
				recordLog(level, msg + "\r\n\t" + e.getMessage());
			}
			
			
			@Override
			public void debug(String msg) {
				recordLog(Level.Debug, msg);
			}
			
			@Override
			public void debug(String msg, Throwable e) {
				recordLog(Level.Debug, msg, e);
			}

			@Override
			public void info(String msg) {
				recordLog(Level.Info, msg);
			}
			
			@Override
			public void info(String msg, Throwable e) {
				recordLog(Level.Info, msg, e);
			}
			@Override
			public void warn(String msg) {
				recordLog(Level.Warn, msg);
			}
			
			@Override
			public void warn(String msg, Throwable e) {
				recordLog(Level.Warn, msg, e);
			}
			@Override
			public void error(String msg) {
				recordLog(Level.Error, msg);
			}
			
			@Override
			public void error(String msg, Throwable e) {
				recordLog(Level.Error, msg, e);
			}

		};
	}
}