Utils.java

package com.android.ted.gank.utils;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Point;
import android.os.Build;
import android.text.TextUtils;
import android.view.Display;
import android.view.WindowManager;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Created by froger_mcs on 05.11.14.
 */
public class Utils {
    private static int screenWidth = 0;
    private static int screenHeight = 0;

    public static int dpToPx(int dp) {
        return (int) (dp * Resources.getSystem().getDisplayMetrics().density);
    }

    public static int getScreenHeight(Context c) {
        if (screenHeight == 0) {
            WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE);
            Display display = wm.getDefaultDisplay();
            Point size = new Point();
            display.getSize(size);
            screenHeight = size.y;
        }

        return screenHeight;
    }

    public static int getScreenWidth(Context c) {
        if (screenWidth == 0) {
            WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE);
            Display display = wm.getDefaultDisplay();
            Point size = new Point();
            display.getSize(size);
            screenWidth = size.x;
        }

        return screenWidth;
    }

    public static boolean isAndroid5() {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
    }

    /***
     * 获取默认格式的日期字符串
     * @param date
     * @return
     */
    public static String getFormatDateStr(final Date date){
        if(null == date)return null;
        return DateFormat.getDateInstance(DateFormat.DEFAULT).format(date);
    }

    public static Date formatDateFromStr(final String dateStr){
        Date date = new Date();
        if(!TextUtils.isEmpty(dateStr)){
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.sss'Z'");
            try {
                date = sdf.parse(dateStr);
            }catch (Exception e){
                System.out.print("Error,format Date error");
            }
        }
        return date;
    }
}