android 计算所在周所在月的前后日期

效果图：

使用了 一个时间相关的工具类

package com.yqy.yqy_date;

import android.util.Log;

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

/**
 * 时间工具类
 * @author YQY
 *
 */
public class ToolDateTime {

    /** 日期格式：yyyy-MM-dd HH:mm:ss **/
    public static final String DF_YYYY_MM_DD_HH_MM_SS = "yyyy-MM-dd HH:mm:ss";

    /** 日期格式：yyyy-MM-dd HH:mm **/
    public static final String DF_YYYY_MM_DD_HH_MM = "yyyy-MM-dd HH:mm";

    /** 日期格式：yyyy-MM-dd **/
    public static final String DF_YYYY_MM_DD = "yyyy-MM-dd";

    /** 日期格式：HH:mm:ss **/
    public static final String DF_HH_MM_SS = "HH:mm:ss";

    /** 日期格式：HH:mm **/
    public static final String DF_HH_MM = "HH:mm";

    private final static long minute = 60 * 1000;// 1分钟
    private final static long hour = 60 * minute;// 1小时
    private final static long day = 24 * hour;// 1天
    private final static long month = 31 * day;// 月
    private final static long year = 12 * month;// 年

    /** Log输出标识 **/
    private static final String TAG = ToolDateTime.class.getSimpleName();

    /**
     * 将日期格式化成友好的字符串：几分钟前、几小时前、几天前、几月前、几年前、刚刚
     * 
     * @param date
     * @return
     */
    public static String formatFriendly(Date date) {
        if (date == null) {
            return null;
        }
        long diff = new Date().getTime() - date.getTime();
        long r = 0;
        if (diff > year) {
            r = (diff / year);
            return r + "年前";
        }
        if (diff > month) {
            r = (diff / month);
            return r + "个月前";
        }
        if (diff > day) {
            r = (diff / day);
            return r + "天前";
        }
        if (diff > hour) {
            r = (diff / hour);
            return r + "个小时前";
        }
        if (diff > minute) {
            r = (diff / minute);
            return r + "分钟前";
        }
        return "刚刚";
    }

    /**
     * 将日期以yyyy-MM-dd HH:mm:ss格式化
     * 
     * @param dateL
     *            日期
     * @return
     */
    public static String formatDateTime(long dateL) {
        SimpleDateFormat sdf = new SimpleDateFormat(DF_YYYY_MM_DD_HH_MM_SS);
        Date date = new Date(dateL);
        return sdf.format(date);
    }

    /**
     * 将日期以yyyy-MM-dd HH:mm:ss格式化
     * 
     * @param dateL
     *            日期
     * @return
     */
    public static String formatDateTime(long dateL, String formater) {
        SimpleDateFormat sdf = new SimpleDateFormat(formater);
        return sdf.format(new Date(dateL));
    }

    /**
     * 将日期以yyyy-MM-dd HH:mm:ss格式化
     * 
     * @param dateL
     *            日期
     * @return
     */
    public static String formatDateTime(Date date, String formater) {
        SimpleDateFormat sdf = new SimpleDateFormat(formater);
        return sdf.format(date);
    }

    /**
     * 将日期字符串转成日期
     * 
     * @param strDate
     *            字符串日期
     * @return java.util.date日期类型
     */
    public static Date parseDate(String strDate) {
        DateFormat dateFormat = new SimpleDateFormat(DF_YYYY_MM_DD_HH_MM_SS);
        Date returnDate = null;
        try {
            returnDate = dateFormat.parse(strDate);
        } catch (ParseException e) {
            Log.v(TAG, "parseDate failed !");

        }
        return returnDate;

    }

    /**
     * 获取系统当前日期
     * 
     * @return
     */
    public static Date gainCurrentDate() {
        return new Date();
    }

    /**
     * 验证日期是否比当前日期早
     * 
     * @param target1
     *            比较时间1
     * @param target2
     *            比较时间2
     * @return true 则代表target1比target2晚或等于target2，否则比target2早
     */
    public static boolean compareDate(Date target1, Date target2) {
        boolean flag = false;
        try {
            String target1DateTime = ToolDateTime.formatDateTime(target1,
                    DF_YYYY_MM_DD_HH_MM_SS);
            String target2DateTime = ToolDateTime.formatDateTime(target2,
                    DF_YYYY_MM_DD_HH_MM_SS);
            if (target1DateTime.compareTo(target2DateTime) <= 0) {
                flag = true;
            }
        } catch (Exception e1) {
            System.out.println("比较失败，原因：" + e1.getMessage());
        }
        return flag;
    }

    /**
     * 对日期进行增加操作
     * 
     * @param target
     *            需要进行运算的日期
     * @param hour
     *            小时
     * @return
     */
    public static Date addDateTime(Date target, double hour) {
        if (null == target || hour < 0) {
            return target;
        }

        return new Date(target.getTime() + (long) (hour * 60 * 60 * 1000));
    }

    /**
     * 对日期进行相减操作
     * 
     * @param target
     *            需要进行运算的日期
     * @param hour
     *            小时
     * @return
     */
    public static Date subDateTime(Date target, double hour) {
        if (null == target || hour < 0) {
            return target;
        }

        return new Date(target.getTime() - (long) (hour * 60 * 60 * 1000));
    }

}

package com.yqy.yqy_date;

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

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {
    private TextView tv_week, tv_month;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv_week = (TextView) findViewById(R.id.tv_week);
        tv_month = (TextView) findViewById(R.id.tv_month);

        Date mDate = new Date();
        Date sDate = null;
        Date eDate = null;
        String sstr = "";
        String estr = "";
        sDate = ToolDateTime.subDateTime(mDate, (mDate.getDay() - 1) * 24);
        for (int i = 0; i < 15; i++) {
            eDate = ToolDateTime.addDateTime(sDate, 6 * 24);
            sstr = ToolDateTime.formatDateTime(sDate,
                    ToolDateTime.DF_YYYY_MM_DD);
            estr = ToolDateTime.formatDateTime(eDate,
                    ToolDateTime.DF_YYYY_MM_DD);
            tv_week.append(sstr + "~" + estr + "n");
            sDate = ToolDateTime.addDateTime(eDate, 24);
        }

        SimpleDateFormat format = new SimpleDateFormat(ToolDateTime.DF_YYYY_MM_DD);
        // 获取当前月第一天：

        String first = "";
        String last = "";

        for (int i = 0; i < 10; i++) {
            Calendar c = Calendar.getInstance();
            Calendar ca = Calendar.getInstance();
            c.add(Calendar.MONTH, i);
            c.set(Calendar.DAY_OF_MONTH, 1);// 设置为1号,当前日期既为本月第一天
            first = format.format(c.getTime());

            // 获取当前月最后一天
            ca.add(Calendar.MONTH, i);
            ca.set(Calendar.DAY_OF_MONTH,
                    ca.getActualMaximum(Calendar.DAY_OF_MONTH));
            last = format.format(ca.getTime());
            tv_month.append(first+"~"+last+"n");
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/tv_week"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_month"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/tv_week"
        android:layout_marginTop="28dp" />

</RelativeLayout>