import java.util.Map;  import java.util.Set;     import android.content.Context;  import android.content.SharedPreferences;  import android.content.SharedPreferences.Editor;     /**   * SharedPreferences工具类   * @author zouyb   *   */  public class SharedPreferencesUtil {         private SharedPreferences sp;      private Editor editor;      private String name = "mosjoy_chat";      private int mode = Context.MODE_PRIVATE;         public SharedPreferencesUtil(Context context) {          this.sp = context.getSharedPreferences(name, mode);          this.editor = sp.edit();      }             /**       * 创建一个工具类，默认打开名字为name的SharedPreferences实例       * @param context       * @param name   唯一标识       * @param mode   权限标识       */      public SharedPreferencesUtil(Context context, String name, int mode) {          this.sp = context.getSharedPreferences(name, mode);          this.editor = sp.edit();      }         /**       * 添加信息到SharedPreferences       *       * @param name       * @param map       * @throws Exception       */      public void add(Map<String, String> map) {          Set<String> set = map.keySet();          for (String key : set) {              editor.putString(key, map.get(key));          }          editor.commit();      }         /**       * 删除信息       *       * @throws Exception       */      public void deleteAll() throws Exception {          editor.clear();          editor.commit();      }         /**       * 删除一条信息       */      public void delete(String key){          editor.remove(key);          editor.commit();      }         /**       * 获取信息       *       * @param key       * @return       * @throws Exception       */      public String get(String key){          if (sp != null) {              return sp.getString(key, "");          }          return "";      }         /**       * 获取此SharedPreferences的Editor实例       * @return       */      public Editor getEditor() {          return editor;      }  }