Android 日誌工具類[支援保存到SD卡] @ 自由手記

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.UnknownHostException;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.annotation.SuppressLint;
import android.os.Environment;
import android.util.Log;

/**
* Android开发调试日志工具类[支持保存到SD卡] 
* 
*
* 需要一些权限: 
* <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
* <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /> 
*
* @author PMTOAM
*
*/
@SuppressLint("SimpleDateFormat")
public class MyLog
{

public static final String CACHE_DIR_NAME = "dPhoneLog";

public static boolean isDebugModel = true;// 是否输出日志
public static boolean isSaveDebugInfo = true;// 是否保存调试日志
public static boolean isSaveCrashInfo = true;// 是否保存报错日志

public static void v(final String tag, final String msg)
{
if (isDebugModel)
{
Log.v(tag, "--> " + msg);
}
}

public static void d(final String tag, final String msg)
{
if (isDebugModel)
{
Log.d(tag, "--> " + msg);
}
}

public static void i(final String tag, final String msg)
{
if (isDebugModel)
{
Log.i(tag, "--> " + msg);
}
}

public static void w(final String tag, final String msg)
{
if (isDebugModel)
{
Log.w(tag, "--> " + msg);
}
}

/**
* 调试日志，便于开发跟踪。
* @param tag
* @param msg
*/
public static void e(final String tag, final String msg)
{
if (isDebugModel)
{
Log.e(tag, "--> " + msg);
}

if (isSaveDebugInfo)
{
new Thread()
{
public void run()
{
write(time() + tag + " --> " + msg + "\n");
};
}.start();
}
}

/**
* try catch 时使用，上线产品可上传反馈。
* @param tag
* @param tr
*/
public static void e(final String tag, final Throwable tr)
{
if (isSaveCrashInfo)
{
new Thread()
{
public void run()
{
write(time() + tag + " [CRASH] --> "
+ getStackTraceString(tr) + "\n");
};
}.start();
}
}

/**
* 获取捕捉到的异常的字符串
* @param tr
* @return
*/
public static String getStackTraceString(Throwable tr)
{
if (tr == null)
{
return "";
}

Throwable t = tr;
while (t != null)
{
if (t instanceof UnknownHostException)
{
return "";
}
t = t.getCause();
}

StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
tr.printStackTrace(pw);
return sw.toString();
}

/**
* 标识每条日志产生的时间
* @return
*/
private static String time()
{
return "["
+ new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(
System.currentTimeMillis())) + "] ";
}

/**
* 以年月日作为日志文件名称
* @return
*/
private static String date()
{
return new SimpleDateFormat("yyyy-MM-dd").format(new Date(System
.currentTimeMillis()));
}

/**
* 保存到日志文件
* @param content
*/
public static synchronized void write(String content)
{
try
{
FileWriter writer = new FileWriter(getFile(), true);
writer.write(content);
writer.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}

/**
* 获取日志文件路径
* @return
*/
public static String getFile()
{
File sdDir = null;

if (Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED))
sdDir = Environment.getExternalStorageDirectory();

File cacheDir = new File(sdDir + File.separator + CACHE_DIR_NAME);
if (!cacheDir.exists())
cacheDir.mkdir();

File filePath = new File(cacheDir + File.separator + date() + ".txt");

return filePath.toString();
}

}
来自：http://blog.csdn.net/wangyuexing_blog/article/details/39005239