-2

我正在尝试为 Android 开发应用程序，但我不知道如何在 Android 手机中写入/读取文件。

通常我会做以下事情：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;

public class Test {

    public static void main(String[] args) {
        try {
            String path = "file.txt";
            BufferedWriter bw = new BufferedWriter(new FileWriter(path));
            bw.write("XYZ");
            bw.close();

            BufferedReader br = new BufferedReader(new FileReader(path));
            String line = "", data = "";
            while ((line = br.readLine()) != null) {
                data = data + line;
            }
            br.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
4

2 回答 2

3

你很接近。这是我做的事情，我检查是否有 SD 卡，如果没有，它将保存在本地（请记住，因为它是一个 Android 应用程序，所以您的所有数据都将保存在手机上），然后您创建如果没有目录，则写入文件。如果您有任何问题，请告诉我。这更多是为了写入，但读取同样简单，您只需创建一个缓冲读取器，给它文件，然后读取；就像您在代码中所做的一样。

我希望这有帮助：

SimpleDateFormat photoFormat = new SimpleDateFormat("ddMMyy-hhmmss");

        // create formating for date
        SimpleDateFormat sdf = new SimpleDateFormat("MMMddyy-hhmmss");
        /*
         * This sections checks the phone to see if there is a SD card. if
         * there is an SD card, a directory is created on the SD card to
         * store the test log results. If there is not a SD card, then the
         * directory is created on the phones internal hard drive
         */
        // if there is no SD card
        if (Environment.getExternalStorageState() == null) {
            directory = new File(Environment.getDataDirectory()
                    + "/RobotiumTestLog/");
            photoDirectory = new File(Environment.getDataDirectory()
                    + "/Robotium-Screenshots/");

            // if no directory exists, create new directory
            if (!directory.exists()) {
                directory.mkdir();
            }

            // if phone DOES have sd card
        } else if (Environment.getExternalStorageState() != null) {
            // search for directory on SD card
            directory = new File(Environment.getExternalStorageDirectory()
                    + "/RobotiumTestLog/");
            photoDirectory = new File(
                    Environment.getExternalStorageDirectory()
                            + "/Robotium-Screenshots/");

            // if no directory exists, create new directory to store test
            // results
            if (!directory.exists()) {
                directory.mkdir();
            }
        }// end of SD card checking

        /*
         * Below is where the name of the test log is created.This can be
         * changed for any other test methods
         */
        String fileName = "TravelTestResults.csv";

        /*
         * Checks for existing test logs, and if they exist, they are
         * deleted, creating a new test log for each testing method
         */
        File logResults = new File(directory, fileName);
        if (logResults.exists()) {
            logResults.delete();
        }
        if (!logResults.exists()) {
            logResults.createNewFile();
        }
        /*
         * This creates the writing stream to log the test results This
         * stream MUST be closed, using bw.close(), for the test results to
         * show on the log. If the stream is not closed, when you open the
         * text file that the results are stored in, the page will be blank.
         */
        bw = new BufferedWriter(new FileWriter(logResults, true));
        bw.write("Test Run, Test Result, Comments \"\n\"");
                    bw.close();
于 2012-07-11T22:23:47.367 回答
3

该文档有一个关于如何最好地访问文件系统的相当不错的指南。

于 2012-07-11T22:48:13.343 回答