java截取日期_Java的String字符串拼接,截取,查找及日期转换

import java.util.Date;

public class JavaString {

public static void main(String[] args) {

//char to string

char a[] &＃61; {&＃39;g&＃39;,&＃39;o&＃39;,&＃39;o&＃39;,&＃39;d&＃39;,&＃39;.&＃39;};

String s  &＃61; new String (a);  //全部字符

System.out.println(s);

String ss &＃61; new String (a,2,2);//部分字符

System.out.println(ss);

//多个字符串连接

String s1 &＃61; new String ("Hello");

String s2 &＃61; new String ("World");

String sss &＃61; s1 &＃43; " "&＃43; s2;

System.out.println(sss);

//连接其它数据类型,int 和float

int booktime &＃61; 4;

float practice &＃61; 2.5f;

System.out.println("我每天花费"&＃43;booktime &＃43;"小时&＃xff1b;"&＃43;practice&＃43;"小时上机练习.");

//String str &＃61; String.format("我每天花费{1}小时看书&＃xff1b;{2}小时上机练                习.",booktime,practice);

//System.out.println(str);

//获得字符串长度&＃xff1a;

String str &＃61; "We are studentsa";

int size &＃61; str.length();

System.out.println("str.length()&＃61;"&＃43;size);

//字符串查找&＃xff1a;

int size1 &＃61; str.indexOf("a");

System.out.println("字符串查找indexOf(a)&＃xff1a;" &＃43; size1);

int size2 &＃61; str.lastIndexOf("a");

System.out.println("字符串查找&＃xff1a;lastIndexOf(a)" &＃43; size2);

//查找空字符串&＃xff1a;

int size3 &＃61; str.indexOf(" ");//int size3 &＃61; str.indexOf("");

System.out.println("空字符串的位置&＃xff1a;"&＃43; size3);

//获得子字符串&＃xff1a;//beginIndex <&＃61; endIndex

String substr &＃61; str.substring(3,4);//String substr &＃61; str.substring(3);

System.out.println("获得子串:"&＃43;substr);

//去掉空格&＃xff1a;

String javaStr &＃61; " Java Class";

System.out.println("字符串原来的长度&＃xff1a;"&＃43; javaStr.length());

System.out.println("去掉空格后字符串的长度&＃xff1a;"&＃43;javaStr.trim().length());

//字符串替换

String address &＃61; "address";

String newstr &＃61; address.replace("a", "A");

System.out.println(newstr);

//判断字符串的开始与结尾&＃xff1a;

String num1 &＃61; "22045612";

String num2 &＃61; "21304578";

boolean b &＃61; num1.startsWith("22");

boolean b2 &＃61; num1.endsWith("78");

boolean b3 &＃61; num2.startsWith("22");

boolean b4 &＃61; num2.endsWith("78");

System.out.println("字符串num1是以&＃39;22&＃39;开始的吗&＃xff1f;"&＃43;b);

System.out.println("字符串num1是以&＃39;78&＃39;结尾的吗&＃xff1f;"&＃43;b2);

System.out.println("字符串num1是以&＃39;22&＃39;开始的吗&＃xff1f;"&＃43;b3);

System.out.println("字符串num1是以&＃39;78&＃39;结尾的吗&＃xff1f;"&＃43;b4);

//判断字符串是否相等

String tom &＃61; new String("I am");

String jerry &＃61; new String("I am");

boolean bb &＃61;(tom&＃61;&＃61;jerry);

boolean bbb &＃61; tom.equals(jerry); //equalsIgnoreCase

System.out.println("tom&＃61;&＃61;jerry:"&＃43;bb);

System.out.println("tom.equals(jerry):"&＃43;bbb);

//字母大小写转换&＃xff1a;

String mystr &＃61; new String("abc DEF");

String newstrs &＃61; mystr.toLowerCase();

String newstrs2 &＃61; mystr.toUpperCase();

System.out.println(newstrs);

System.out.println(newstrs2);

//字符串分割&＃xff1a;

String splitStr &＃61; new String("abc,def,ghi,gkl");

String [] newsplitstr &＃61; splitStr.split(",");

for(int i&＃61;0;i

{

System.out.println(newsplitstr[i]);

}

String [] newsplitstr2 &＃61; splitStr.split(",",2);//限定拆分次数

for(int i&＃61;0;i

{

System.out.println(newsplitstr2[i]);

}

//格式化字符串&＃xff1a;

//日期格式化

//%te   一个月中的某一天(1-31)

//%tb  月份

//%tB  月份的全称

//%tA 星期几全称

//%ta 星期几

//%tc

//%tY  4位年份(2009)

//%tj 一年中的第几天(001-366)

//%tm 月份

//%td 一个月中的第几天(01-31)

//%ty 2位年份

Date date &＃61; new Date();

String dates &＃61; String.format("%te", date);

String datedays &＃61; String.format("%tj", date);

System.out.println("日期&＃xff1a;"&＃43;dates);

System.out.println("一年中的第几天&＃xff1a;"&＃43;datedays);

//时间格式化&＃xff1a;

//%tH 2位24小时数&＃xff1a;(00-23)

//%tI 2位12小时数&＃xff1a;(01-12)

//%tk 2位24小时数&＃xff1a;(0-23)

//%tl 2位12小时数&＃xff1a;(1-12)

//%tM 2位数字的分钟(00-59)

//%tS 2位数字的秒(00-60)

//%tL 8位毫秒(000-999)

//%tN 9位毫秒()

//%tp  上下午&＃xff0c;

//%tz

//%tZ

//%ts 1970-01-01 00:00:00至今经过的秒

//%tQ 1970-01-01 00:00:00至今经过的毫秒

String hour &＃61; String.format("%tH", date);

String minute &＃61; String.format("%tM", date);

String second &＃61; String.format("%tS", date);

String msecond &＃61; String.format("%tQ", date);

System.out.println("现在是"&＃43;hour&＃43;"时"&＃43;minute&＃43;"分"&＃43;second&＃43;"秒");

System.out.println("现在是毫秒&＃xff1a;"&＃43;msecond);

//日期时间组合&＃xff1a;

//%tF 年-月-日

//%tD 月/日/年

//%tc 全部日期和时间信息

//%tr 时分秒上下午

//%tT 时分秒

//%tR 时分

String time &＃61; String.format("%tc", date);

String form &＃61; String.format("%tF", date);

String sfm  &＃61; String.format("%tT", date);

System.out.println("全部时间信息&＃xff1a;"&＃43;time);

System.out.println("年-月-日格式&＃xff1a;"&＃43;form);

System.out.println("时分秒&＃xff1a;"&＃43; sfm);

System.out.println("date.toString():" &＃43; date.toString());//date.toLocaleString()

System.out.println("date.toLocaleString():" &＃43; date.toLocaleString());

//使用正则表达式

//字符串生成器&＃xff1a;StringBuilder

//builder.append();insert(int offset arg);delete(int start,int end);

StringBuilder bf &＃61; new StringBuilder("Hello");

bf.insert(5, "word");

System.out.println(bf.toString());

}

}