Java 2Se With Jdeveloper 11G

1-Bitwise Operators


2-Code Points and Code Units


-To get at the ith code point, use the statements
int index = greeting.offsetByCodePoints(0, i);
int cp = greeting.codePointAt(index); ماذا يعني هذا الكلام وما هو ال code point
-Why are we making a fuss about code units? Consider the sentence
is the set of integers
The character requires two code units in the UTF-16 encoding. Calling
char ch = sentence.charAt(1)
doesn’t return a space but the second code unit of . To avoid this problem, you should
not use the char type. It is too low-level.
If your code traverses a string, and you want to look at each code point in turn, use
these statements:
int cp = sentence.codePointAt(i);
if (Character.isSupplementaryCodePoint(cp)) i += 2;
else i++;
Fortunately, the codePointAt method can tell whether a code unit is the first or second half
of a supplementary character, and it returns the right result either way. That is, you can
move backwards with the following statements:
i--;
int cp = sentence.codePointAt(i);
if (Character.isSupplementaryCodePoint(cp)) i--;

وماذا يعني هذا
-• StringBuilder appendCodePoint(int cp)
appends a code point, converting it into one or two code units, and returns this.
• void setCharAt(int i, char c)
sets the ith code unit to c.
• StringBuilder insert(int offset, String str)
inserts a string at position offset and returns this.
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وأخيرا
كيف يمكنني تفعيل الـ stuart console in jdeveloper 11g
مثلا اقوم بكتابة هذا الكود داخل البرنامج ولم يقوم بتنفيذه وعند تنفيذه عن طريق cmd يقوم بتنفيذة

package test;

import java.io.Console;


public class TestClass {
public static void main(String[] args) {
TestClass testClass = new TestClass();

Console cons = System.console();
String username = cons.readLine("User name: ");
char[] passwd = cons.readPassword("Password: ");

}
}

وشكرا جدا جدا