JavaString 字符串拼接,截取,查找及日期转换

System.out.println("现在是毫秒："+msecond);
//日期时间组合：
//%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 = String.format("%tc", date);
//字母大小写转换：
String mystr = new String("abc DEF");
String newstrs = mystr
.toLowerCase();
String newstrs2 = mystr.toUpperCase();
System.out.println(newstrs);
System.out.println("空字符串的位置："+ size3);
//获得子字符串：//beginIndex <= endIndex
String substr = str.substring(3,4);//String substr = str.substring(3);
boolean b2 = num1.endsWith("78");
boolean b3 = num2.startsWith("22");
boolean b4 = num2.endsWith("78");
System.out.println("字符串num1是以'22'开始的吗？"+b);
//%tQ 1970-01-01 00:00:00至今经过的毫秒
String hour = String.format("%tH", date);
String minute = String.format("%tM", date);
String second = String.format("%tS", date);
System.out.println(newstrs2);
//字符串分割：
String splitStr = new String("abc,def,ghi,gkl");
String [] newsplitstr = splitStr.split(",");
//判断字符串是否
相等
String tom = new String("I am");
String jerry = new String("I am");
//System.out.println(str);
//获得字符串长度：
String str = "We are studentsa";
int size = str.length();
System.out.println("str.length()="+size);
//%tl 2位12小时数：(1-12)
//%tM 2位数字的分钟(00-59)
//%tS 2位数的秒(00-60)
//%tL 8位毫秒(000-999)
//%tN 9位毫秒()
//%tp 上下午，
//%tz
//%tZ
//%ts 1970-01-01 00:00:00至今经过的秒
String s = new String (a); //全部字符
System.out.println(s);
String ss = new String (a,2,2);//部分字符
System.out.println(ss);
//多个字符串连接
String s1 = new String ("Hello");
String form = String.format("%tF", date);
String sfm = String.format("%tT", date);
System.out.println("全部时间信息："+time);
System.out.println("去掉空格后字符串的长度："+javaStr.trim().length());
//字符串替换
String address = "address";
String newstr = address.replace("a", "A");
System.out.println("我每天花费"+booktime +"小时看书；"+practice+"小时上机练习.");
//String str = String.format("我每天花费{1}小时看书；{2}小时上机练习.",booktime,practice);
System.out.println("字符串num1是以'78'结尾的吗？"+b2);
System.out.println("字符串num1是以'22'开始的吗？"+b3);
System.out.println("字符串num1是以'78'结尾的吗？"+b4);
String s2 = new String ("World");
String sss = s1 + " "+ s2;
System.out.println(sss);
//连接其它数据类型,int 和float
int booktime = 4;
float practice = 2.5f;
//builder.append();insert(int offset arg);delete(int start,int end);
StringBuilder bf = new StringBuilder("Hello");
for(int i=0;i<newsplitstr.length;i++)
{
System.out.println(newsplitstr[i]);
}
String [] newsplitstr2 = splitStr.split(",",2);//限定拆分次数
for(int i=0;i<newsplitstr2.length;i++)
System.out.println("获得子串:"+substr);
//去掉空格：
String javaStr = " Java Class";
System.out.println("字符串原来的长度："+ javaStr.length());
System.out.println("日期："+dates);
System.out.println("一年中的第几天："+datedays);
//时间格式化：
//%tH 2位24小时数：(00-23)
//%tI 2位12小时数：(01-12)
//%tk 2位24小时数：(0-23)
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//char to string
char a[] = {'g','o','o','d','.'};
System.out.println("年-月-日格式："+form);
System.out.println("时分秒："+ sfm);
System.out.println("date.toString():" + date.toString());//date.toLocaleString()