我正在尝试将用户设置保存到一个文件中,以便以后可以从中读取。但我无法让它正常工作。我已尝试阅读此内容,但仍有问题。
Map<String, String> userSettings = new HashMap<>();
public void updateUserSettings(){
userSettings.clear();
userSettings.put("item0", item0);
userSettings.put("item1", item1);
userSettings.put("item2", item2);
userSettings.put("item3", item3);
userSettings.put("item4", item4);
userSettings.put("item5", item5);
userSettings.put("item6", item6);
userSettings.put("item7", item7);
userSettings.put("i0", Float.toString(i0));
userSettings.put("i1", Float.toString(i1));
userSettings.put("i2", Float.toString(i2));
userSettings.put("i3", Float.toString(i3));
userSettings.put("i4", Float.toString(i4));
userSettings.put("i5", Float.toString(i5));
userSettings.put("i6", Float.toString(i6));
userSettings.put("i7", Float.toString(i7));
userSettings.put("huvudMaskin", huvudMaskin);
userSettings.put("minorMaskin1", minorMaskin1);
userSettings.put("minorMaskin2", minorMaskin2);
userSettings.put("maskinTid", Float.toString(maskinTid));
writeSettings();
}
public void writeSettings() {
try
{
FileOutputStream fos = context.openFileOutput("test.ser", Context.MODE_PRIVATE);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(userSettings);
oos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public void readSetttings() {
try
{
FileInputStream fileInputStream = new FileInputStream(context.getFilesDir()+"test.ser");
ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
Map myHashMap = (Map)objectInputStream.readObject();
userSettings = null;
userSettings = myHashMap;
}
catch(ClassNotFoundException | IOException | ClassCastException e) {
e.printStackTrace();
}
executeSettings();
}
我拥有该应用程序的读写权限。
我没有从中得到任何东西。我检查了 HashMap ,它按预期工作。我也尝试了很多不同的方法,唯一成功的方法是将字符串保存到 .txt 文件中。
最佳答案
private String subFolder = "/userdata";
private String file = "test.ser";
public void writeSettings() {
File cacheDir = null;
File appDirectory = null;
if (android.os.Environment.getExternalStorageState().
equals(android.os.Environment.MEDIA_MOUNTED)) {
cacheDir = getApplicationContext().getExternalCacheDir();
appDirectory = new File(cacheDir + subFolder);
} else {
cacheDir = getApplicationContext().getCacheDir();
String BaseFolder = cacheDir.getAbsolutePath();
appDirectory = new File(BaseFolder + subFolder);
}
if (appDirectory != null && !appDirectory.exists()) {
appDirectory.mkdirs();
}
File fileName = new File(appDirectory, file);
FileOutputStream fos = null;
ObjectOutputStream out = null;
try {
fos = new FileOutputStream(fileName);
out = new ObjectOutputStream(fos);
out.writeObject(userSettings);
} catch (IOException ex) {
ex.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (fos != null)
fos.flush();
fos.close();
if (out != null)
out.flush();
out.close();
} catch (Exception e) {
}
}
}
public void readSetttings() {
File cacheDir = null;
File appDirectory = null;
if (android.os.Environment.getExternalStorageState().
equals(android.os.Environment.MEDIA_MOUNTED)) {
cacheDir = getApplicationContext().getExternalCacheDir();
appDirectory = new File(cacheDir + subFolder);
} else {
cacheDir = getApplicationContext().getCacheDir();
String BaseFolder = cacheDir.getAbsolutePath();
appDirectory = new File(BaseFolder + subFolder);
}
if (appDirectory != null && !appDirectory.exists()) return; // File does not exist
File fileName = new File(appDirectory, file);
FileInputStream fis = null;
ObjectInputStream in = null;
try {
fis = new FileInputStream(fileName);
in = new ObjectInputStream(fis);
Map<String, String> myHashMap = (Map<String, String> ) in.readObject();
userSettings = myHashMap;
System.out.println("count of hash map::"+userSettings.size() + " " + userSettings);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (StreamCorruptedException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}finally {
try {
if(fis != null) {
fis.close();
}
if(in != null) {
in.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
关于java - 如何将 HashMap 保存到 Android 中的文件?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41392602/