实现思路：
1.需要给工具类里传入context；
2.使用上下文mContext.startActivity启动activity
例子1：
public class SafePlaceRecyclerViewAdapter {private Context mContext;public SafePlaceRecyclerViewAdapter(Context context){mContext = context;}public void start(){Intent intent = new Intent(mContext,SafeAreaInformation.class);mContext.startActivity(intent);}}例子2：
public class SafePlaceRecyclerViewAdapter extends RecyclerView.Adapter<SafePlaceRecyclerViewAdapter.ViewHolder> {private List <SafePlaceData> mList;private Context mContext;public SafePlaceRecyclerViewAdapter(Context context, List<SafePlaceData> list){this.mList = list;mContext = context;}@Overridepublic ViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.safe_place_row_layout,parent,false);ViewHolder viewHolder = new ViewHolder(view);viewHolder.safePlaceRowLayout.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(v.getContext(),SafeAreaInformation.class);mContext.startActivity(intent);}});return viewHolder;}