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  • android 文件读写

    public static String _getJsonString(String fileName)
    throws IOException {
    if ((fileName == null) || fileName.isEmpty()) {
    return "";
    }
    String retString = "";
    FileInputStream fis = null;
    String state = Environment.getExternalStorageState();
    if (state.equals(Environment.MEDIA_MOUNTED)) {
    File file = new File(Environment.getExternalStorageDirectory()
    + "/" + fileName + ".json");
    if (file.exists()) {
    fis = new FileInputStream(file);
    byte[] buffer = new byte[fis.available()];
    fis.read(buffer);
    fis.close();

    retString = new String(buffer);
    } else {

    }
    }
    return retString;
    }
    写:

    public static void saveSettingFile(String fileName, String content) {
    FileOutputStream fos = null;
    String state = Environment.getExternalStorageState();
    if (state.equals(Environment.MEDIA_MOUNTED)) {
    File file = new File(Environment.getExternalStorageDirectory()
    + "/" + fileName + ".json");
    try {
    fos = new FileOutputStream(file);
    byte[] buffer = content.getBytes();
    fos.write(buffer);
    fos.close();
    } catch (FileNotFoundException e) {
    e.printStackTrace();
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    }
    Gson 读写:

    public static void saveServerInfo(String fileName, String content) {
    FileOutputStream fos = null;
    String state = Environment.getExternalStorageState();
    if (state.equals(Environment.MEDIA_MOUNTED)) {
    File file = new File(Environment.getExternalStorageDirectory()
    + "/" + fileName + ".json");
    try {
    fos = new FileOutputStream(file);
    byte[] buffer = content.getBytes();
    fos.write(buffer);
    fos.close();
    } catch (FileNotFoundException e) {
    e.printStackTrace();
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    }

    public static ServerInfo getServerInfo(String fileName)
    throws IOException {
    ServerInfo serverInfo = new ServerInfo();
    if ((fileName == null) || fileName.isEmpty()) {
    serverInfo = null;
    return serverInfo;
    }
    FileInputStream fis = null;
    String state = Environment.getExternalStorageState();
    if (state.equals(Environment.MEDIA_MOUNTED)) {
    File file = new File(Environment.getExternalStorageDirectory()
    + "/" + fileName + ".json");
    if (file.exists()) {
    fis = new FileInputStream(file);
    byte[] buffer = new byte[fis.available()];
    fis.read(buffer);
    fis.close();

    Gson gson = new Gson();
    serverInfo = gson.fromJson(new String(buffer),
    ServerInfo.class);
    } else {
    serverInfo = null;
    }
    }
    return serverInfo;
    }
    调用:

    public void onSetIPAndPort(View view) {
    ServerInfo serverInfo = new ServerInfo();
    try {
    serverInfo = JsonFileWriteAndRead.getServerInfo("videochat");
    } catch (IOException e) {
    e.printStackTrace();
    }

    //写入ip和端口
    String ip = ipSet.getText().toString();
    String port = portSet.getText().toString();
    serverInfo.setIpString(ip);
    serverInfo.setPortString(port);
    Gson gson = new Gson();
    if (ip.isEmpty() || port.isEmpty()) {
    Toast.makeText(this, "地址或端口为空", Toast.LENGTH_SHORT).show();
    } else {
    JsonFileWriteAndRead.saveServerInfo("videochat", gson.toJson(serverInfo));
    Toast.makeText(this, "地址和端口已经写入文件", Toast.LENGTH_SHORT).show();
    }
    }
    --------------------- 

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  • 原文地址:https://www.cnblogs.com/ly570/p/10971100.html
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