Android 日志工具

目标实现功能

• 打印日志到控制台和文件中
• 日志支持在logcat 窗口 有链接跳转到对应的位置，文件中就直接拷贝内容到logcat 窗口 也支持链接
• 文件支持设置文件大小和最大数量

使用方法：

LogUtil.d("process------------>");

一共有两个文件LogUtil和LogFileUtil，代码如下：

import android.util.Log;
/**
 * 输出各种级别的log到控制台
 * msg字符长度不受限制，默认的Log是受限制的，超过的部分不输出
 * 输出的log头有链接，可以点击链接到执行代码文件位置
 * 可以直接输出msg,使用默认Tag
 * 支持设置 LEVEL，小于LEVEL级别以下不再打印log
 */
public class LogUtil {
    private static final String TAG = "LogUtil";
    public static int LEVEL = Log.VERBOSE;
    public static void v(String TAG, String msg) {
        if (LEVEL <= Log.VERBOSE) {
            logWithLink(Log.VERBOSE, TAG, msg);
        }
    }
    public static void d(String TAG, String msg) {
        if (LEVEL <= Log.DEBUG) {
            logWithLink(Log.DEBUG, TAG, msg);
        }
    }
    public static void i(String TAG, String msg) {
        if (LEVEL <= Log.INFO) {
            logWithLink(Log.INFO, TAG, msg);
        }
    }
    public static void w(String TAG, String msg) {
        if (LEVEL <= Log.WARN) {
            logWithLink(Log.WARN, TAG, msg);
        }
    }
    public static void e(String TAG, String msg) {
        if (LEVEL <= Log.ERROR) {
            logWithLink(Log.ERROR, TAG, msg);
        }
    }
    public static void v(String msg) {
        if (LEVEL <= Log.VERBOSE) {
            logWithLink(Log.VERBOSE, TAG, msg);
        }
    }
    public static void d(String msg) {
        if (LEVEL <= Log.DEBUG) {
            logWithLink(Log.DEBUG, TAG, msg);
        }
    }
    public static void i(String msg) {
        if (LEVEL <= Log.INFO) {
            logWithLink(Log.INFO, TAG, msg);
        }
    }
    public static void w(String msg) {
        if (LEVEL <= Log.WARN) {
            logWithLink(Log.WARN, TAG, msg);
        }
    }
    public static void e(String msg) {
        if (LEVEL <= Log.ERROR) {
            logWithLink(Log.ERROR, TAG, msg);
        }
    }
    //Log输出的最大长度
    private static int LOG_MAX_LENGTH = 2000;//2000
    /**
     * 循环打印log，解决msg过长不打印问题
     */
    private static void LogWrapperLoop(int logPriority, String TAG, String msg) {
        int msgLength = msg.length();
        /**
         * adb  lgh=3
         *  ^
         *  |   index=1
         * print a
         */
        int index = 0;//输出字符的位置
        while (index < msgLength) {
            if (index   LOG_MAX_LENGTH > msgLength) {
                LogWrapper(logPriority, TAG, msg.substring(index, msgLength));
            } else {
                LogWrapper(logPriority, TAG, msg.substring(index, index   LOG_MAX_LENGTH));
            }
            index  = LOG_MAX_LENGTH;
        }
    }
    private static void LogWrapper(int logPriority, String TAG, String msg) {
        switch (logPriority) {
            case Log.VERBOSE:
                LogFileUtil.v(TAG, msg);
                Log.v(TAG, msg);
                break;
            case Log.DEBUG:
                LogFileUtil.d(TAG, msg);
                Log.d(TAG, msg);
                break;
            case Log.INFO:
                LogFileUtil.i(TAG, msg);
                Log.i(TAG, msg);
                break;
            case Log.WARN:
                LogFileUtil.w(TAG, msg);
                Log.w(TAG, msg);
                break;
            case Log.ERROR:
                LogFileUtil.e(TAG, msg);
                Log.e(TAG, msg);
                break;
            case Log.ASSERT:
                break;
            default:
                break;
        }
    }
    /**
     * 带有链接的log打印
     */
    private static void logWithLink(int logPriority, String TAG, String msg) {
        StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
        int index = 4;
        String className = stackTrace[index].getFileName();
        String methodName = stackTrace[index].getMethodName();
        int lineNumber = stackTrace[index].getLineNumber();
        methodName = methodName.substring(0, 1).toUpperCase()   methodName.substring(1);
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("[ (").append(className).append(":").append(lineNumber).append(")#").append(methodName).append(" ] ");
        stringBuilder.append(msg);
        String logStr = stringBuilder.toString();
        LogWrapperLoop(logPriority, TAG, logStr);
    }
}

import android.util.Log;

import java.io.File;
import java.io.FileWriter;
import java.io.FilenameFilter;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Date;
import java.util.concurrent.Executors;

/**
 * 将日志打印到文件：
 * <p>
 * 支持设置文件最大大小LOG_SIZE_MAX  KB，超过大小重新创建文件（由于文件名是以毫秒为维度理论不会重复）
 * 支持文件总个数LOG_FILE_TOTAL，超过总个数删除最先创建的文件
 * 支持设置日志文件输出目录LOG_FILE_PRINT_DIR
 */
public class LogFileUtil {
    // 日志文件总数
    private static final int LOG_FILE_TOTAL = 10;
    // 单日志文件大小上限 KB
    private static final long LOG_SIZE_MAX = 5 * 1024;
    // 日志文件输出文件夹
    private static final String LOG_FILE_PRINT_DIR = "/sdcard/MyProject/log/info/";
    // 文件名格式
    private static final SimpleDateFormat FILE_NAME_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss-SSS");
    //创建一个可重用固定线程数的线程池
    private static java.util.concurrent.ExecutorService singleThreadPool = Executors.newSingleThreadExecutor();

    public static final void v(String TAG, String msg) {
        printLog("VERBOSE", TAG, msg);
    }
    public static final void d(String TAG, String msg) {
        printLog("DEBUG", TAG, msg);
    }
    public static final void i(String TAG, String msg) {
        printLog("INFO ", TAG, msg);
    }
    public static final void w(String TAG, String msg) {
        printLog("WARN ", TAG, msg);
    }
    public static final void e(String TAG, String msg) {
        printLog("ERROR", TAG, msg);
    }
    private static void printLog(final String level, final String TAG, final String msg) {
        singleThreadPool.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    FileWriter fileWriter = new FileWriter(getFile(), true);
                    fileWriter.write(formatLog(level, TAG, msg));
                    fileWriter.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

    }

    //格式化日志
    private static String formatLog(String level, String TAG, String msg) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        StringBuilder builder = new StringBuilder();
        builder.append(dateFormat.format(new Date(System.currentTimeMillis()))   " ");
        builder.append("["   level   "] ");
        builder.append("["   TAG   "] ");
        builder.append(msg);
        builder.append("\n");
        return builder.toString();
    }

    // 获取需要输出的日志文件
    private static File getFile() {
        // 确认文件夹是否存在
        File fileDir = new File(LOG_FILE_PRINT_DIR);
        if (!fileDir.exists()) {
            fileDir.mkdirs();
        }
        // 获取文件夹下的日志文件
        File[] fileList = fileDir.listFiles(new FilenameFilter() {
            @Override
            public boolean accept(File dir, String name) {
                return name.endsWith(".log");
            }
        });
        int fileCount = fileList == null ? 0 : fileList.length;

        // 没有日志文件时，直接创建新文件
        if (fileCount == 0) {
            return createLogFile();
        }
        // 只有一个日志文件时
        if (fileCount == 1) {
            return isCreateLogFile(fileList[0]);
        }
        // 对日志排序，排序结果为升序
        Arrays.sort(fileList, new Comparator<File>() {
            @Override
            public int compare(File file1, File file2) {
                String file1Name = "";
                String file2Name = "";
                try {
                    file1Name = file1.getName().split(".log")[0];
                    file2Name = file2.getName().split(".log")[0];

                    Date dateFile1 = FILE_NAME_FORMAT.parse(file1Name);
                    Date dateFile2 = FILE_NAME_FORMAT.parse(file2Name);
                    return dateFile1.getTime() < dateFile2.getTime() ? -1 : 1;
                } catch (Exception e) {
                    Log.i("LogUtil", "file1Name:"   file1Name   ",   file2Name:"   file2Name);
                    e.printStackTrace();

                }
                return 0;
            }
        });
        File lastFile = fileList[fileCount - 1];
        // 日志文件未超过最大控制个数
        if (fileCount < LOG_FILE_TOTAL) {
            return isCreateLogFile(lastFile);
        }
        if (sizeOf(lastFile) >= LOG_SIZE_MAX) {
            // 删除时间最早的一个文件
            fileList[0].delete();
        }
        return isCreateLogFile(lastFile);
    }

    // 确认是否需要创建新日志文件
    private static File isCreateLogFile(File file) {
        // 超过日志文件大小上限，需要创建新日志文件
        if (sizeOf(file) >= LOG_SIZE_MAX) {
            return createLogFile();
        }
        return file;
    }

    // 创建一个新的日志文件
    private static File createLogFile() {
        return new File(LOG_FILE_PRINT_DIR   FILE_NAME_FORMAT.format(new Date(System.currentTimeMillis()))   ".log");
    }
    // 计算文件大小，返回单位 KB
    private static long sizeOf(File file) {
        long length = file.length();
        return length / 1024;
    }

}

来源：https://www./content-4-888351.html