Android 读写日志文件

重要的点

1. 把错误信息保存到一个String变量中

public static void print(String str){
        FileWriter fw = null;
        BufferedWriter bw = null;
        try {
            fw =  new FileWriter(logFilePath);
            bw =  new BufferedWriter(fw);
            bw.write(str);
            bw.write("\n");
            bw.newLine();
            bw.flush();
            bw.close();
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

2. 获取文件的大小

FileInputStream is = new FileInputStream(logFile);
                int length = is.available();

3. 获取Android Cache 目录

public static final String logFilePath = MyApplication.getMyApplicationContext().getCacheDir()+"/myLog.txt";

4. 读取文件的方法 并转换成String

private void readFile() {
        File file = new File(LogFileUtil.logFilePath);
        if (file.exists()) {
            try {
                FileInputStream fis = new FileInputStream(file);
                int length = fis.available();
                logFileInfo = "文件路径： \n" + LogFileUtil.logFilePath + "\n";
                logFileInfo = logFileInfo + "length: " + length + " byte\n";
                byte[] buffer = new byte[length];
                fis.read(buffer);
                String ss = new String(buffer, "UTF-8");
                mTvLogContent.setText(ss);
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
                mTvLogContent.setText("读取日志错误");
            }
        }
    }