android 对象保存到SP

1.工具类

package com.you.me.utils;

import android.app.Activity;
import android.app.ActivityManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.util.Base64;

import android.widget.TextView;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

/**
* @author cao_zhi_qing
* @version Revision: 1.0 Date: 2015/1/2
*/
public class ContextUtils {
/**
* 把对象保存到以String形式保存到sp中
* @param context 上下文
* @param t 泛型参数
* @param spName sp文件名
* @param keyName 字段名
* @param
*/
public static void saveObj2SP(Context context, T t, String spName, String keyName) {

    SharedPreferences preferences = context.getSharedPreferences(spName, Context.MODE_PRIVATE);    ByteArrayOutputStream bos;    ObjectOutputStream oos = null;    try {        bos = new ByteArrayOutputStream();        oos = new ObjectOutputStream(bos);        oos.writeObject(t);        byte[] bytes = bos.toByteArray();

// String ObjStr = new String(bytes,0,bytes.length);
String ObjStr = Base64.encodeToString(bytes, Base64.DEFAULT);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(keyName, ObjStr);
editor.commit();
} catch (IOException e) {
e.printStackTrace();
} finally {
//关闭流
if (oos != null) {
try {
oos.flush();
oos.close();
} catch (IOException e) {
e.printStackTrace();
}

        }    }}/** * sp文件名 和 字段名相同 * @param context * @param t * @param spName * @param  */public static  void saveObj2SP(Context context, T t, String spName) {    saveObj2SP(context, t, spName, spName);}/** *从sp中读取对象 * @param context * @param spName sp文件名 * @param keyNme 字段名 * @param     泛型参数 * @return */public static  T getObjFromSp(Context context, String spName, String keyNme) {    SharedPreferences preferences = context.getSharedPreferences(spName, Context.MODE_PRIVATE);    byte[] bytes = Base64.decode(preferences.getString(keyNme, ""), Base64.DEFAULT);    ByteArrayInputStream bis;    ObjectInputStream ois = null;    T obj = null;    try {        bis = new ByteArrayInputStream(bytes);        ois = new ObjectInputStream(bis);        obj = (T) ois.readObject();    } catch (IOException e) {        e.printStackTrace();    } catch (ClassNotFoundException e) {        e.printStackTrace();    } finally {        if (ois != null) {            try {                ois.close();            } catch (IOException e) {                e.printStackTrace();            }        }    }    return obj;}public static  T getObjFromSp(Context context, String spName){    return  getObjFromSp(context,spName,spName);}

}

2.被保存的对象要先序列化 Serializable。
package com.example.customView;

import java.io.Serializable;

/**
* @author cao_zhi_qing
* @version Revision: 1.0 Date: 2015/6/29
* @Description:请用一句话描述此类
*/
public class Entity implements Serializable {

private String name;private String address;public String getName() {    return name;}public void setName(String name) {    this.name = name;}public String getAddress() {    return address;}public void setAddress(String address) {    this.address = address;}

}

3保存对象、获取对象。
package com.example.customView;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;

public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
private TitleView titleView ;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Entity entity = new Entity();
entity.setName(“name”);
entity.setAddress(“address”);
ContextUtils.saveObj2SP(this,entity,”entity”);

    Entity entity1 = ContextUtils.getObjFromSp(this,"entity");    System.out.println(entity1.getName());    System.out.println(entity1.getAddress());}

}

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