hashmap和SharedPreferences存储
把hashmap转换成string,然后存到共享参数里面,然后从共享参数取数据
step1: HelloActivity
package com.example.myapplication;
import static com.example.myapplication.ExtrasKt.FIRST_GUID_NET;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import com.google.gson.Gson;
import java.util.HashMap;
public class HelloActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hello);
Button btn_hello = findViewById(R.id.btn_hello);
btn_hello.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
hashmapTest();
}
});
}
private void hashmapTest() {
HashMap<String, String> testHashMap = new HashMap<String, String>();
testHashMap.put("A4:C1:07:7F:74:2B", "通断器");
testHashMap.put("A7:C1:07:7F:74:2B", "随意贴");
Gson gson = new Gson();
String hashMapString = gson.toJson(testHashMap);
SpUtils.putString(HelloActivity.this, FIRST_GUID_NET, hashMapString);
Intent intent = new Intent(HelloActivity.this,FirstActivity.class);
startActivity(intent);
}
}
step2: FirstActivity
package com.example.myapplication;
import static com.example.myapplication.ExtrasKt.FIRST_GUID_NET;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.util.HashMap;
public class FirstActivity extends AppCompatActivity {
private TextView tv_first;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first);
tv_first = findViewById(R.id.tv_first);
Button btn_hello = findViewById(R.id.btn_first);
btn_hello.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
hashmapTest();
}
});
}
private void hashmapTest() {
Gson gson = new Gson();
String data = SpUtils.getString(FirstActivity.this, FIRST_GUID_NET, "");
Type type = new TypeToken<HashMap<String, String>>() {}.getType();
HashMap<String, String> testHashMap2 = gson.fromJson(data, type);
String toastString = testHashMap2.get("A4:C1:07:7F:74:2B") + " | " + testHashMap2.get("A7:C1:07:7F:74:2B");
tv_first.setText(toastString);
}
}
step3: Extras
package com.example.myapplication
const val LAST_FLOAT_X = "LAST_FLOAT_X"
const val LAST_FLOAT_Y = "LAST_FLOAT_Y"
const val FIRST_START = "first_start"
const val FIRST_GUID = "first_guid"
const val FIRST_TOKEN = "first_token"
const val BLE_TOKEN = "ble_token"
const val FIRST_GUID_MAIN = "first_guid_main"
const val FIRST_GUID_NET = "first_guid_net"
const val WALL_BG = "wall_bg"
const val WALL_BG_COLOR = "wall_bg_color"
const val RULE_URL = "https://mg.mindordz.com/privacy"
step4: SpUtils
package com.example.myapplication;
import android.content.Context;
import android.content.SharedPreferences;
import android.util.Log;
/**
* 文件:SpUtils
* 时间:2018/9/5.
* 备注:
*/
public class SpUtils {
public static String PREFERENCE_NAME = "rebate_sp";
private SpUtils() {
throw new AssertionError();
}
/**
* put string preferences
*
* @param context
* @param key The name of the preference to modify
* @param value The new value for the preference
* @return True if the new values were successfully written to persistent storage.
*/
public static boolean putString(Context context, String key, String value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value);
return editor.commit();
}
/**
* get string preferences
*
* @param context
* @param key The name of the preference to retrieve
* @return The preference value if it exists, or null. Throws ClassCastException if there is a preference with this
* name that is not a string
* @see #getString(Context, String, String)
*/
public static String getString(Context context, String key) {
return getString(context, key, null);
}
/**
* get string preferences
*
* @param context
* @param key The name of the preference to retrieve
* @param defaultValue Value to return if this preference does not exist
* @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with
* this name that is not a string
*/
public static String getString(Context context, String key, String defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getString(key, defaultValue);
}
/**
* put int preferences
*
* @param context
* @param key The name of the preference to modify
* @param value The new value for the preference
* @return True if the new values were successfully written to persistent storage.
*/
public static boolean putInt(Context context, String key, int value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putInt(key, value);
return editor.commit();
}
/**
* get int preferences
*
* @param context
* @param key The name of the preference to retrieve
* @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this
* name that is not a int
* @see #getInt(Context, String, int)
*/
public static int getInt(Context context, String key) {
return getInt(context, key, -1);
}
/**
* get int preferences
*
* @param context
* @param key The name of the preference to retrieve
* @param defaultValue Value to return if this preference does not exist
* @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with
* this name that is not a int
*/
public static int getInt(Context context, String key, int defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getInt(key, defaultValue);
}
/**
* put long preferences
*
* @param context
* @param key The name of the preference to modify
* @param value The new value for the preference
* @return True if the new values were successfully written to persistent storage.
*/
public static boolean putLong(Context context, String key, long value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putLong(key, value);
return editor.commit();
}
/**
* get long preferences
*
* @param context
* @param key The name of the preference to retrieve
* @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this
* name that is not a long
* @see #getLong(Context, String, long)
*/
public static long getLong(Context context, String key) {
return getLong(context, key, -1);
}
/**
* get long preferences
*
* @param context
* @param key The name of the preference to retrieve
* @param defaultValue Value to return if this preference does not exist
* @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with
* this name that is not a long
*/
public static long getLong(Context context, String key, long defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getLong(key, defaultValue);
}
/**
* put float preferences
*
* @param context
* @param key The name of the preference to modify
* @param value The new value for the preference
* @return True if the new values were successfully written to persistent storage.
*/
public static boolean putFloat(Context context, String key, float value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putFloat(key, value);
return editor.commit();
}
/**
* get float preferences
*
* @param context
* @param key The name of the preference to retrieve
* @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this
* name that is not a float
* @see #getFloat(Context, String, float)
*/
public static float getFloat(Context context, String key) {
return getFloat(context, key, -1);
}
/**
* get float preferences
*
* @param context
* @param key The name of the preference to retrieve
* @param defaultValue Value to return if this preference does not exist
* @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with
* this name that is not a float
*/
public static float getFloat(Context context, String key, float defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getFloat(key, defaultValue);
}
/**
* put boolean preferences
*
* @param context
* @param key The name of the preference to modify
* @param value The new value for the preference
* @return True if the new values were successfully written to persistent storage.
*/
public static boolean putBoolean(Context context, String key, boolean value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean(key, value);
return editor.commit();
}
/**
* get boolean preferences, default is false
*
* @param context
* @param key The name of the preference to retrieve
* @return The preference value if it exists, or false. Throws ClassCastException if there is a preference with this
* name that is not a boolean
* @see #getBoolean(Context, String, boolean)
*/
public static boolean getBoolean(Context context, String key) {
return getBoolean(context, key, false);
}
/**
* get boolean preferences
*
* @param context
* @param key The name of the preference to retrieve
* @param defaultValue Value to return if this preference does not exist
* @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with
* this name that is not a boolean
*/
public static boolean getBoolean(Context context, String key, boolean defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getBoolean(key, defaultValue);
}
}
end