Android 使用SharedPreferences存取数据
这里还包含了文件存储，注意这个文件是与app关联的，app删掉，文件不存在了。
SharedPreferences很常用，因此我把它整理成一个工具类，使用方法如下
存：CacheUtil.getInstance().setString(“key”, “value”);
取： CacheUtil.getInstance().getString(“key”);
工具源码：CacheUtil.java。
由于使用了apply方法进行提交保存，我这里设置了隔一定时间自动保存，这样能有效提高保存的效率，也减少了代码量，尤其在批量保存时，当然这里也提供了较实时的提交方法applyNow();。
地址：https://github.com/LINC365/jars/blob/master/CacheUtil.java
package ******p;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Handler;
import android.text.TextUtils;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
/**
* 公共存储工具，
* created by lkl
* 2019年8月9日11:50:20
*/
public class CacheUtil {
private static final StringERROR_FILENAME_EMPTY ="文件名不能为空";
private static final StringERROR_FILEDATA_EMPTY ="存储内容不能为空";
private static final StringERROR_FILE_NOT_EXIST ="文件不存在";
private static final int ZERO =0;
private static final boolean FALSE=false;
private static final StringEMPTY="";
private static SharedPreferencessp;
private static CacheUtilinstance;
private static SharedPreferences.Editoredt;
private CacheUtil() {
sp = MyApplication.getInstance().getApplicationContext().getSharedPreferences("myapps1", Context.MODE_PRIVATE);
}
private SharedPreferences.EditorgetEditor() {
if (edt ==null) {
synchronized (SharedPreferences.Editor.class) {
if (edt ==null) {
edt =sp.edit();
}
}
}
return edt;
}
public static CacheUtilgetInstance() {
if (instance ==null) {
synchronized (CacheUtil.class) {
if (instance ==null) {
instance =new CacheUtil();
}
}
}
return instance;
}
public void setInt(String key, int value) {
getEditor().putInt(key, value);
apply();
}
public int getInt(String key) {
return sp.getInt(key, ZERO);
}
public void setString(String key, String value) {
getEditor().putString(key, value);
apply();
}
public StringgetString(String key) {
return sp.getString(key, EMPTY);
}
public void setLong(String key, long value) {
getEditor().putLong(key, value);
apply();
}
public long getLong(String key) {
return sp.getLong(key, ZERO);
}
public void setBoolean(String key, boolean b) {
getEditor().putBoolean(key, b);
apply();
}
public boolean getBoolean(String key) {
return sp.getBoolean(key, FALSE);
}
public void removeContent(String name) {
getEditor().remove(name);
apply();
}
public void clearContent() {
getEditor().clear();
apply();
}
public void crearContent(String key) {
getEditor().remove(key);
apply();
}
public void applyNow() {
handler.post(runnable);
}
private void apply() {
if (!isWating) {
isWating =true;
handler.postDelayed(runnable, 500);
}
oneTimeSaveCount++;
}
private int oneTimeSaveCount =0;
private boolean isWating =false;
private Handlerhandler =new Handler();
private Runnablerunnable =new Runnable() {
@Override
public void run() {
try {
getEditor().apply();
isWating =false;
oneTimeSaveCount =0;
}catch (Exception e) {
Logger.e("键值保存失败数据量(" +oneTimeSaveCount +")" + e.getMessage());
oneTimeSaveCount =0;
}
}
};
public void saveDataToFile(final String fileName, final String data, final OnMyFileSaveListener onMyFileSaveListener) {
if (TextUtils.isEmpty(fileName)) {
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(EMPTY, ERROR_FILENAME_EMPTY);
}
return;
}
if (TextUtils.isEmpty(data)) {
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, ERROR_FILEDATA_EMPTY);
}
return;
}
new Thread(new Runnable() {
@Override
public void run() {
FileOutputStream out;
BufferedWriter writer =null;
try {
//设置文件名称，以及存储方式
out = MyApplication.getInstance().getApplicationContext().openFileOutput(fileName, Context.MODE_PRIVATE);
//创建一个OutputStreamWriter对象，传入BufferedWriter的构造器中
writer =new BufferedWriter(new OutputStreamWriter(out));
//向文件中写入数据
writer.write(data);
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onSavedListener(data.getBytes().length, data.getBytes().length, fileName);
}
}catch (IOException e) {
// Logger.e("文件存储失败[" + fileName + "][" + data.substring(data.length() / 3) + "...]" + e.getMessage());
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, e.getMessage());
}
}finally {
try {
assert writer !=null;
writer.close();
}catch (IOException e) {
// Logger.e("文件存储writer.close()失败[" + fileName + "]" + e.getMessage());
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, "[writer.close()]" + e.getMessage());
}
}
}
}
}).start();
}
private void resetFileContentEmpty(final String fileName, final OnMyFileSaveListener onMyFileSaveListener){
if (TextUtils.isEmpty(fileName)) {
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(EMPTY, ERROR_FILENAME_EMPTY);
}
return;
}
if (!fileExist(fileName)) {
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, ERROR_FILE_NOT_EXIST);
}
return;
}
new Thread(new Runnable() {
@Override
public void run() {
FileOutputStream out;
BufferedWriter writer =null;
try {
//设置文件名称，以及存储方式
out = MyApplication.getInstance().getApplicationContext().openFileOutput(fileName, Context.MODE_PRIVATE);
//创建一个OutputStreamWriter对象，传入BufferedWriter的构造器中
writer =new BufferedWriter(new OutputStreamWriter(out));
//向文件中写入数据
writer.write(EMPTY);
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onSavedListener(EMPTY.getBytes().length, EMPTY.getBytes().length, fileName);
}
}catch (IOException e) {
// Logger.e("文件存储失败[" + fileName + "][" + data.substring(data.length() / 3) + "...]" + e.getMessage());
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, e.getMessage());
}
}finally {
try {
assert writer !=null;
writer.close();
}catch (IOException e) {
// Logger.e("文件存储writer.close()失败[" + fileName + "]" + e.getMessage());
if (onMyFileSaveListener !=null) {
onMyFileSaveListener.onErrorListener(fileName, "[writer.close()]" + e.getMessage());
}
}
}
}
}).start();
}
public void getDataFromFile(final String fileName, final OnMyFileGetListener onMyFileGetListener) {
if (TextUtils.isEmpty(fileName)) {
if (onMyFileGetListener !=null) {
onMyFileGetListener.onErrorListener(EMPTY, ERROR_FILENAME_EMPTY);
}
return;
}
if (!fileExist(fileName)) {
if (onMyFileGetListener !=null) {
onMyFileGetListener.onErrorListener(fileName, ERROR_FILE_NOT_EXIST);
}
return;
}
new Thread(new Runnable() {
@Override
public void run() {
FileInputStream in;
BufferedReader reader =null;
StringBuilder content =new StringBuilder();
try {
//设置将要打开的存储文件名称
in = MyApplication.getInstance().getApplicationContext().openFileInput(fileName);
//FileInputStream -> InputStreamReader ->BufferedReader
reader =new BufferedReader(new InputStreamReader(in));
String line;
//读取每一行数据，并追加到StringBuilder对象中，直到结束
while ((line = reader.readLine()) !=null) {
content.append(line);
}
if (onMyFileGetListener !=null) {
onMyFileGetListener.onGetedListener(content.length(), fileName, content.toString());
}
}catch (IOException e) {
if (onMyFileGetListener !=null) {
onMyFileGetListener.onErrorListener(fileName, e.getMessage());
}
}finally {
if (reader !=null) {
try {
reader.close();
}catch (IOException e) {
if (onMyFileGetListener !=null) {
onMyFileGetListener.onErrorListener(fileName, "[writer.close()]" + e.getMessage());
}
}
}
}
}
}).start();
}
public void deleteFile(final String fileName) {
if (TextUtils.isEmpty(fileName)) {
return;
}
if (!fileExist(fileName)) {
return;
}
new Thread(new Runnable() {
@Override
public void run() {
try {
resetFileContentEmpty(fileName, new OnMyFileSaveListener() {
@Override
public void onSavedListener(int i1, int i2, String fileName) {
if (i1 ==0) {
Logger.i("退出登录后，" + fileName +"已置空");
}else{
Logger.i("退出登录后，无法将" + fileName +"置空");
}
}
@Override
public void onErrorListener(String fileName, String errorMsg) {
Logger.i("退出登录后，无法将" + fileName +"置空");
}
});
}catch (Exception e) {
Logger.e("文件删除失败" + e.getMessage());
}
}
}).start();
}
private static String[]list_dbfile;
private static String[]getList_dbfile() {
if (list_dbfile ==null ||list_dbfile.length <=0) {
list_dbfile = MyApplication.getInstance().getApplicationContext().fileList();
}
return list_dbfile;
}
public boolean fileExist(String fileName) {
if (TextUtils.isEmpty(fileName)) {
return false;
}
for (String s :getList_dbfile()) {
if (fileName.equals(s)) {
return true;
}
}
return false;
}
public interface OnMyFileGetListener {
void onGetedListener(int i1, String fileName, String data);
void onErrorListener(String fileName, String errorMsg);
}
public interface OnMyFileSaveListener {
void onSavedListener(int i1, int i2, String fileName);
void onErrorListener(String fileName, String errorMsg);
}
}
