Java8クラス

</pre><span style="font-size:14px">①StringBuilderクラス</span><p></p><pre name="code" class="java">package com.aegeanworkjp.API;

public class StringBuilderClass {

public static void main(String[] args) {
// TODO Auto-generated method stub
StringBuilder builder=new StringBuilder("Hello World!");
//容量数を確認
System.out.println("容量数："+builder.capacity());
//データを回転させる
System.out.println(builder.reverse());
builder.append("What a beautiful day!");
//ストリムを追加する
System.out.println("The length of"+builder.toString()+":"+builder.length());
//ASCIIコード番号による文字追加
System.out.println(builder.appendCodePoint(65));
//insert(int offset,Object xxxx)
System.out.println(builder.insert(builder.length(),"B"));
//replace(int start,int end,String xxx)
//０から始まり文字列の長さ−１までに書き換える
System.out.println(builder.replace(0,12,"world").toString()+"----->「!dlroW olleH」's length:"+"!dlroW olleH".length());
//文字列削除
//delete(int start,int end)
System.out.println(builder.delete(0, 5).toString());
//容量を実際の長さに縮小する
builder.trimToSize();
System.out.println(builder.toString());
//指定文字削除
System.out.println(builder.deleteCharAt(builder.length()-1).toString());
//容量数を確認
System.out.println("容量数："+builder.capacity());
}

}

容量数：28
!dlroW olleH
The length of!dlroW olleHWhat a beautiful day!:33
!dlroW olleHWhat a beautiful day!A
!dlroW olleHWhat a beautiful day!AB
worldWhat a beautiful day!AB----->「!dlroW olleH」's length:12
What a beautiful day!AB
What a beautiful day!AB
What a beautiful day!A
容量数：23

package com.aegeanworkjp.API;
import java.time.*;
public class LocalDateClass {

public static void main(String[] args) {
// TODO Auto-generated method stub
LocalDate date=LocalDate.now();
System.out.println("Current Date:"+date);

//of(int year,int month,int day)
LocalDate date1=LocalDate.of(Year.now().getValue(), Month.MARCH, 20);
System.out.println("Current Date1:"+date1);

LocalDate date2=LocalDate.now(ZoneId.of("Asia/Tokyo"));
System.out.println("Current Date by zone:"+date2);

LocalDate date3=LocalDate.ofYearDay(Year.now().getValue(), 77);
System.out.println("77th day of this year:"+date3);
System.out.println("minus 44 day :"+date3.minusDays(44));
}
}

Current Date:2016-04-19
Current Date1:2016-03-20
Current Date by zone:2016-04-19
77th day of this year:2016-03-17
minus 44 day :1972-03-17

package com.aegeanworkjp.API;
import java.time.*;
public class LocalDateClass {

public static void main(String[] args) {
// TODO Auto-generated method stub
LocalDate date=LocalDate.now();
System.out.println("Current Date:"+date);

//of(int year,int month,int day)
LocalDate date1=LocalDate.of(Year.now().getValue(), Month.MARCH, 20);
System.out.println("Current Date1:"+date1);

LocalDate date2=LocalDate.now(ZoneId.of("Asia/Tokyo"));
System.out.println("Current Date by zone:"+date2);

LocalDate date3=LocalDate.ofYearDay(Year.now().getValue(), 77);
System.out.println("77th day of this year:"+date3);
System.out.println("minus 44 day :"+date3.minusDays(44));
}
}

Current Date:2016-04-19
Current Date1:2016-03-20
Current Date by zone:2016-04-19
77th day of this year:2016-03-17
minus 44 day :2016-02-02

package com.aegeanworkjp.API;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.Month;
import java.time.ZoneId;
import java.time.ZoneOffset;

public class LocalDateTimeClass {

public static void main(String[] args) {
// TODO Auto-generated method stub

LocalDateTime today = LocalDateTime.now();
System.out.println("Current DateTime="+today);

//of(int year,int month,int day,int hour,int minute,int second)
today = LocalDateTime.of(LocalDate.now(), LocalTime.now());
System.out.println("Current DateTime="+today);

LocalDateTime specificDate = LocalDateTime.of(LocalDate.now().getYear(), Month.JANUARY, 1, 10, 10, 30);
System.out.println("Specific Date="+specificDate);

//Current date in "Asia/Tokyo", you can get it from Tokyo
LocalDateTime todayJapn = LocalDateTime.now(ZoneId.of("Asia/Tokyo"));
System.out.println("Current Date in JST="+todayJapn);

//Getting date from the base date i.e 01/01/1970
LocalDateTime dateFromBase = LocalDateTime.ofEpochSecond(10000, 0, ZoneOffset.UTC);
System.out.println("10000th second time from 01/01/1970= "+dateFromBase);
}

}

Current DateTime=2016-04-19T23:10:23.317
Current DateTime=2016-04-19T23:10:23.318
Specific Date=2016-01-01T10:10:30
Current Date in JST=2016-04-19T23:10:23.318
10000th second time from 01/01/1970= 1970-01-01T02:46:40

package com.aegeanworkjp.API;

import java.time.Duration;
import java.time.Instant;

public class DurationClass {
public static void main(String[] args) {
Instant start = Instant.now();
Instant end = Instant.now();
Duration durate = Duration.between(start, end);
long millis=durate.toMinutes();
System.out.println("Time:"+millis+" ZERO:"+durate.isZero());
System.out.println("Time plus:"+durate.plusMillis(2000).toNanos());
System.out.println(Duration.parse("P2DT3H4M").toMinutes());
}
}

Time:0 ZERO:true
Time plus:2000000000
3064

DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss.SSS")

2014/07/21 22:16:46.348

DateTimeFormatter.ISO_ZONED_DATE_TIME

2014
95b6
-07-21T22:16:46.348+09:00[Asia/Tokyo]

DateTimeFormatter.ISO_OFFSET_DATE_TIME

2014-07-21T22:16:46.348+09:00

DateTimeFormatter.ISO_OFFSET_DATE

2014-07-21+09:00

DateTimeFormatter.ISO_OFFSET_TIME

22:16:46.348+09:00

DateTimeFormatter.ISO_LOCAL_DATE_TIME

2014-07-21T22:16:46.348

DateTimeFormatter.ISO_LOCAL_DATE

2014-07-21

DateTimeFormatter.ISO_LOCAL_TIME

22:16:46.348

package com.aegeanworkjp.API;

import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;

public class DateTimeFormatterInterface {

public static void main(String[] args) {

//DateTimeFormatter.ofLocalizedDate(FormatStyle dateStyle)
DateTimeFormatter format=DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL);
DateTimeFormatter format2=DateTimeFormatter.ofLocalizedDate(FormatStyle.LONG);
DateTimeFormatter format3=DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM);
DateTimeFormatter format4=DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT);
System.out.println("format1:"+format.format(ZonedDateTime.now()));
System.out.println("format2:"+format2.format(ZonedDateTime.now()));
System.out.println("format3:"+format3.format(ZonedDateTime.now()));
System.out.println("format4:"+format4.format(ZonedDateTime.now()));

DateTimeFormatter format5 = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss.SSSxxxxx VV");
System.out.println("format5:"+format5.format(ZonedDateTime.now()));

DateTimeFormatter format6 = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
String text = "2016/04/19 23:36:41";
System.out.println("format6:"+format6.parse(text));
}
}

format1:2016年4月19日
format2:2016/04/19
format3:2016/04/19
format4:16/04/19
format5:2016/04/19 23:38:58.442+09:00 Asia/Tokyo
format6:{},ISO resolved to 2016-04-19T23:36:41