SharedPreferences

调用putParam 就能保存String, Integer, Boolean, Float, Long类型的参数
调用getParam就能获取到保存在手机里面的数据

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.util.Base64;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Map;

public class SPUtils {
/**

• 保存在手机里面的文件名
  */
  public static final String FILE_NAME = "share_data";

/**

• 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法
  */
  public static void putParam(Context context, String key, Object object) {

SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();

if (object instanceof String) {
  editor.putString(key, (String) object);
} else if (object instanceof Integer) {
  editor.putInt(key, (Integer) object);
} else if (object instanceof Boolean) {
  editor.putBoolean(key, (Boolean) object);
} else if (object instanceof Float) {
  editor.putFloat(key, (Float) object);
} else if (object instanceof Long) {
  editor.putLong(key, (Long) object);
} else {
  editor.putString(key, object.toString());
}
SharedPreferencesCompat.apply(editor);

}

    //保存对象

public static boolean setObjectToShare(Context context, Object object, String key) {
// TODO Auto-generated method stub
SharedPreferences share = PreferenceManager
.getDefaultSharedPreferences(context);
if (object == null) {
SharedPreferences.Editor editor = share.edit().remove(key);
return editor.commit();
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = null;
try {
oos = new ObjectOutputStream(baos);
oos.writeObject(object);
} catch (IOException e) {
e.printStackTrace();
return false;
}
// 将对象放到OutputStream中
// 将对象转换成byte数组，并将其进行base64编码
String objectStr = new String(Base64.encode(baos.toByteArray(),
Base64.DEFAULT));
try {
baos.close();
oos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SharedPreferences.Editor editor = share.edit();
// 将编码后的字符串写到base64.xml文件中
editor.putString(key, objectStr);
return editor.commit();
}

//获取对象
public static Object getObjectFromShare(Context context, String key) {
SharedPreferences sharePre = PreferenceManager
.getDefaultSharedPreferences(context);
try {
String wordBase64 = sharePre.getString(key, "");
// 将base64格式字符串还原成byte数组
if (wordBase64 == null || wordBase64.equals("")) { // 不可少，否则在下面会报java.io.StreamCorruptedException
return null;
}
byte[] objBytes = Base64.decode(wordBase64.getBytes(),
Base64.DEFAULT);
ByteArrayInputStream bais = new ByteArrayInputStream(objBytes);
ObjectInputStream ois = new ObjectInputStream(bais);
// 将byte数组转换成product对象
Object obj = ois.readObject();
bais.close();
ois.close();
return obj;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

/**

• 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值
  */
  public static Object getParam(Context context, String key, Object defaultObject) {
  SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
  if (defaultObject instanceof String) {
  return sp.getString(key, (String) defaultObject);
  } else if (defaultObject instanceof Integer) {
  return sp.getInt(key, (Integer) defaultObject);
  } else if (defaultObject instanceof Boolean) {
  return sp.getBoolean(key, (Boolean) defaultObject);
  } else if (defaultObject instanceof Float) {
  return sp.getFloat(key, (Float) defaultObject);
  } else if (defaultObject instanceof Long) {
  return sp.getLong(key, (Long) defaultObject);
  }

return null;

}

/**

• 移除某个key值已经对应的值
  */
  public static void remove(Context context, String key) {
  SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
  SharedPreferences.Editor editor = sp.edit();
  editor.remove(key);
  SharedPreferencesCompat.apply(editor);
  }

/**

• 清除所有数据
  */
  public static void clear(Context context) {
  SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
  SharedPreferences.Editor editor = sp.edit();
  editor.clear();
  SharedPreferencesCompat.apply(editor);
  }

/**

• 查询某个key是否已经存在
  */
  public static boolean contains(Context context, String key) {
  SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
  return sp.contains(key);
  }

/**

• 返回所有的键值对
  */
  public static Map<String, ?> getAll(Context context) {
  SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
  return sp.getAll();
  }

/**

• 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类

*/
private static class SharedPreferencesCompat {
private static final Method sApplyMethod = findApplyMethod();

/**
 * 反射查找apply的方法
 */
@SuppressWarnings({ "unchecked", "rawtypes" }) private static Method findApplyMethod() {
  try {
    Class clz = SharedPreferences.Editor.class;
    return clz.getMethod("apply");
  } catch (NoSuchMethodException e) {
  }

  return null;
}

/**
 * 如果找到则使用apply执行，否则使用commit
 */
public static void apply(SharedPreferences.Editor editor) {
  try {
    if (sApplyMethod != null) {
      sApplyMethod.invoke(editor);
      return;
    }
  } catch (IllegalArgumentException e) {
  } catch (IllegalAccessException e) {
  } catch (InvocationTargetException e) {
  }
  editor.commit();
}

}
}