软件中log日志的创建_小小测试

                       知足常乐
Log工具类：

package com.zzl.test;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import android.util.Log;

/**
 * Created by zzl
 * Date: 2012-03-03
 * 记录log日志文件的工具类
 */ 

public class LogTool {
	private static LogTool instance;
    private PrintWriter logPrint;
    private String logFile = "";
    private String taskNo = "";//任务号
	private String rootDir = "/sdcard/SGWS/log";//日记文件为sdcard/SGWS/任务号/日志文件

    /**
     * 配置没有头的log
    */
    private LogTool(){
        checkDate();//检查日期如果改变新建log文件
    } 
    public static LogTool getInstance() {
		if (instance == null) {
			instance = new LogTool();
		}
		return instance; 
	}
    /**
     * 配置log文件名的头
    */
    public LogTool(String logName){
        checkDate();
    } 
    /**
     * 将java.util.Date格式转换为字符串格式”yyyy-MM-dd HH:mm:ss“
     * 如Sat May 11 17:24:21 CST 2002 to '20002-05011 17:24:21'  
     * @param time Date日期
     * @return字符串
     */
    public String dateToString(Date time){
    	SimpleDateFormat formatter;
    	formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    	String ctime = formatter.format(time);
    	return ctime;
    }
    /**
     * 得到log文件名
    */
    private String getLogFile(){
        String date = "";
        Calendar cd = Calendar.getInstance();
        int y = cd.get(Calendar.YEAR);
        int m = cd.get(Calendar.MONTH) + 1;
        int d = cd.get(Calendar.DAY_OF_MONTH); 
       /* if(null==taskNo || "".equals(taskNo)){
        	date = rootDir+"log/" + logName + y + "-"; 
        }else{
        	date = rootDir+taskNo+"/log/" + logName + y + "-"; 
        }*/
        date = rootDir+"/"+ y + "-"; 
        if(m < 10)
            date += 0; 
        date += m + "-"; 
        if(d < 10)
            date += 0; 
        date += d + ".log"; 
        return date;
    } 

    /**
     * 配置log属性，如果没有新建log文件
    */
    private void newLog(){
        logFile = getLogFile();//创建log文件名 
        try{
        	File filePath = new File(rootDir);
        	if(!filePath.exists()){
        		filePath.mkdirs();
        	}
        	File file = new File(logFile);
        	if(!file.exists()){
        		file.createNewFile();
        	}
        	//(new File(logFile)).mkdir(); 
            logPrint = new PrintWriter(new FileWriter(logFile, true), true);
        }catch(IOException e){
        	File filePath = new File(rootDir);
        	if(!filePath.exists()){
        		filePath.mkdirs();
        	}
        	File file = new File(logFile);
        	if(!file.exists()){
        		try {
					file.createNewFile();
				} catch (IOException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}
        	}
            
            try{
                logPrint = new PrintWriter(new FileWriter(logFile, true), true);
            }catch(IOException ex){
                System.err.println("无法打开日志文件：" + logFile);
                logPrint = new PrintWriter(System.err);
            }
        }
    } 

    /**
     * 检查日期如果改变新建log文件
    */
    private void checkDate(){
    	Log.e("LogTool.checkDate()文件名：", logFile);
        if(logFile == null || logFile.trim().equals("") || !logFile.equals(getLogFile())){
            newLog();
        }
    } 

    /**
     * 将文本信息写入日志文件，缺省为userdir/log
    */
    public void log(String msg) {
    	//this.taskNo = taskNo;
        checkDate();
        logPrint.println(dateToString(new Date()) + "\t" + msg+"\r\n");
        logPrint.close();
    } 

    /**
     * 将文本信息与异常写入日志文件
    */
    public void log(Throwable e, String msg) {
    	//this.taskNo = taskNo;
        checkDate();
        logPrint.println(dateToString(new Date()) + "\t" + msg+"\r\n");
        e.printStackTrace(logPrint);
        logPrint.close();
    }
}

Activity中调用：

package com.zzl.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Button btn = (Button) findViewById(R.id.button1);
        
        btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View arg0) {
				LogTool.getInstance().log("MainActivity.onCreate.btn.OnClickListener");
			}
		});
    }
}

即的权限的添加，ok ！