Android之SharedPreferencesUtils，支持对象，List

有3点厉害的地方

1.使用方便，因为获取了泛型T的class

2.用流处理对象的转化

3.支持List

package com.example.test;

import android.content.Context;
import android.content.SharedPreferences;
import android.util.Base64;
import android.util.Log;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.util.List;

public abstract class SharedPreferencesUtils<T> {
    private Context context;
    private Class<T> clx;
    private String fileName;

private String fileName = "default";

private int mode = Context. MODE_PRIVATE; public SharedPreferencesUtils(Context context) { this. context = context; } public SharedPreferencesUtils(Context context, Class< T> clx) { this. context = context; this. clx = clx; } public SharedPreferencesUtils setFileName(String fileName) { this. fileName = fileName; return this; } public void put(String key, String val) { SharedPreferences sp = context.getSharedPreferences( fileName, mode); SharedPreferences.Editor editor = sp.edit(); editor.putString(key, val); editor.apply(); } public void put(String key, int val) { SharedPreferences sp = context.getSharedPreferences( fileName, mode); SharedPreferences.Editor editor = sp.edit(); editor.putInt(key, val); editor.apply(); } public void put(String key, boolean val) { SharedPreferences sp = context.getSharedPreferences( fileName, mode); SharedPreferences.Editor editor = sp.edit(); editor.putBoolean(key, val); editor.apply(); } public void put(String key, float val) { SharedPreferences sp = context.getSharedPreferences( fileName, mode); SharedPreferences.Editor editor = sp.edit(); editor.putFloat(key, val); editor.apply(); } public void put(String key, long val) { SharedPreferences sp = context.getSharedPreferences( fileName, mode); SharedPreferences.Editor editor = sp.edit(); editor.putLong(key, val); editor.apply(); } public void put(String key, Object val) { ByteArrayOutputStream bos = new ByteArrayOutputStream(); try { ObjectOutputStream os = new ObjectOutputStream(bos); os.writeObject(val); } catch (IOException e) { e.printStackTrace(); } byte[] bytes = bos.toByteArray(); String base64String = Base64. encodeToString(bytes, Base64. NO_WRAP); put(key, base64String); } public T get(String key) { SharedPreferences sp = context.getSharedPreferences( fileName, Context. MODE_PRIVATE); Class< T> tClass = (Class< T>) ((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[ 0]; if (tClass == String. class) { return ( T) sp. getString(key, ""); } else if (tClass == Integer. class) { return ( T)(Integer)sp.getInt(key, 0); } else if (tClass == Float. class) { return ( T)(Float)sp.getFloat(key, 0.0f); } else if (tClass == Long. class) { return ( T)(Long)sp.getLong(key, 0L); } else if (tClass == Boolean. class) { return ( T)(Boolean)sp.getBoolean(key, false); } else { String s = sp. getString(key, ""); byte[] bytes = Base64. decode(s, Base64. NO_WRAP); ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes); ObjectInputStream objectInputStream; try { objectInputStream = new ObjectInputStream(byteArrayInputStream); try { return ( T)objectInputStream.readObject(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } catch (IOException e) { e.printStackTrace(); } return null; } } public List< T> getList(String key) { SharedPreferences sp = context.getSharedPreferences( fileName, Context. MODE_PRIVATE); String s = sp. getString(key, ""); Class< T> tClass = (Class< T>) ((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[ 0]; byte[] bytes = Base64. decode(s, Base64. NO_WRAP); ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes); ObjectInputStream objectInputStream = null; try { objectInputStream = new ObjectInputStream(byteArrayInputStream); try { //我不知道能否直接强转 sorry return (List< T>) objectInputStream.readObject(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } catch (IOException e) { e.printStackTrace(); } return null; }}

如果用fastJson会很方便，但是这是工具类，为了这个工具类去下载一个jar包？肯定不划算啊，所以必须也要封装一个流转化形式的

使用起来非常方便

new 一下，set一下FileName，条理很清晰，最后放就是put，取就是get