1. 无法连接电脑进行调试（usb线被usbotg占用）
2. Log不容易被抓取
3. Bug出现很随机，不是必出现
4. 其他自己脑补

0.说明

这篇文章最早是在我的CSDN博客上面发布了:http://blog.csdn.net/grackergao/article/details/18322749 .现在讲他转移到了这里,代码的Github地址 :https://github.com/Gracker/Android-Utils/blob/master/Log2File.java

1.Log2File工具类源码

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Date;

import android.content.Context;
import android.os.Environment;

public class Log2File
{
  private static boolean logInit;
  private static BufferedWriter writer;

  private Log2File()
  {

  }

  /**
   * 初始化Log,创建log文件
   * @param ctx
   * @param fileName
   * @return
   */
  public static boolean init(Context ctx, String fileName)
  {
    if(!logInit)
    {
      String state = Environment.getExternalStorageState();
      if (Environment.MEDIA_MOUNTED.equals(state))
      {
        File sdDir = Environment.getExternalStorageDirectory();
        File logDir = new File(sdDir.getAbsolutePath() + "/log2file/" +
            ctx.getPackageName() + "/");

        try {
          if(!logDir.exists())
          {
            logDir.mkdirs();
          }

          File logFile = new File(logDir, fileName);
          logFile.createNewFile();

          writer = new BufferedWriter(new FileWriter(logFile, true));
          logInit = true;
        } catch (IOException e) {
          e.printStackTrace();
        }

      }

    }

    return logInit;
  }

  /**
   * 写一条log
   * @param msg
   */
  public static void w(String msg)
  {
    if(logInit)
    {
      try {
        Date date = new Date();
        writer.write("[" + date.toLocaleString() + "] " + msg);
        writer.newLine();
        writer.flush();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  /**
   * 关闭log
   */
  public static void close()
  {
    if(logInit)
    {
      try {
        writer.close();
        writer = null;

      } catch (IOException e) {
        e.printStackTrace();
      }

      logInit = false;
    }
  }
}

2.Log2File类的使用

这个工具类的使用比较简单

1.首先调用init进行初始化

Log2File.init(context, fileName);

Log2File.w(String msg);

Log2File.close();