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1 Java updated

3 3 1 Java Java Java Java Java Java Java Java Java if switch while do-while for break continue return

5 5 1 Java 1.1 Java Java ( Java ) Smalltalk C const final ANSI C ( C ) Java Java ( ) Java Java Java Java Java Java Java Java Java C Java Java GUI Java 1.2 Java Java.java Java

6 6 1 Java.class Java 1.1 javac java (applet) Java Web 1.1: Java 1.3 Java Java Java Java Java Java Java Java Java 2 Runtime Environment: JRE Java 2 Software Development Kit: SDK JRE SDK JRE SDK JRE Java 2 SDK

7 1.3. Java 7 Download J2SE v Windows Windows Offline Installation Linux Linux RPM in self-extracting file Linux self-extracting file Linux Linux self-extracting file RPM SDK DOWNLOAD Keep Informed Java download Java OS OS Windows Windows C:\j2sdk1.4.2 Linux Linux j2sdk-1_4_2-linux-i586.bin % chmod +x j2sdk-1_4_2-linux-i586.bin Enter j2sdk-1_4_2-linux-i586.bin %./j2sdk-1_4_2-linux-i586.bin Enter j2sdk-1_4_2 Java -localinstall /etc %./j2sdk-1_4_2-linux-i586.bin -localinstall Enter /usr/local /usr/local

8 8 1 Java Java PATH Java Java CLASSPATH Java Java Windows WindowsNT OS Windows2000 WindowsXP PATH C:\j2sdk1.4.2\bin PATH PATH Java ; PATH C:\j2sdk1.4.2\bin CLASSPATH CLASSPATH Windows My Documents Linux PATH CLASSPATH 1) csh csh tcsh setenv.cshrc.tcsh % setenv grep PATH Enter CLASSPATH=.:/home/murao/java PATH=...:/usr/local/jdk1.2.2/bin:... java.cshrc Java

9 1.3. Java 9 $HOME java setenv PATH ${PATH:/usr/local/jdk1.2.2/bin setenv CLASSPATH.:${HOME/java 2) bash OS Linux bash export.bashrc % export grep PATH Enter declare -x CLASSPATH=".:/home/murao/java" declare -x PATH="...:/usr/local/jdk1.2.2/bin:..." java.bashrc export PATH="${PATH:/usr/local/jdk1.2.2/bin" export CLASSPATH=".:${HOME/java" Java Hello World Java public class HelloWorld { public static void main( String[] args ) { System.out.println("Hello World"); main HelloWorld main Java public static void main(string[] args) {... emacs HelloWorld.java

10 10 1 Java Java % javac HelloWorld.java Enter HelloWorld.class Java % java HelloWorld Enter HelloWorld.java 1.4 Java Fibonacci( ) Fibonacci Fibonacci Liber abaci(1202 ) n F n F 1 = F 2 = 1 F n+2 = F n+1 + F n, n = 1, 2, 3,... (1.1) F n Fibonacci 1, 1, 2, 3, 5, 8, 13, 21, 34, 55,... (1.2)

11 1.4. Java 11 public class Fibonacci { /** 100 Fibonacci */ public static void main( String[] args ) { int f1 = 1; int f2 = 1; System.out.println(f1); while( f2 < 100 ) { System.out.println(f2); int t = f2; f2 = f1 + f2; f1 = t; // /* */ HelloWorld main Fibonacci main 2 2 f1 f2 C f1 f2 int int C 32 C (C++ ) Fibonacci t while Java ( ) char 8bit int 32 long 64 boolean char byte int long float double true false 16 Unicode Java

12 12 1 Java A B A5061 A A A5061 A A1201 A Java Java 3 /*... */ /* */ //... // /**... */ /** */ Fibonacci main javadoc HTML C const Java final 2 π

13 1.4. Java 13 public class Circle { final double pi = ; length = 2 * pi * r; main static static static public class Circle { static final double pi = ; static double calccircumference() { length = 2 * pi * r; public class Circle { static double calccircumference() { final double pi = ; length = 2 * pi * r; π π π public class CircleStuff { static final double pi = ; static π CircleStuff.pi

14 14 1 Java Circle public class Circle { length = 2 * CircleStuff.pi * r;

15 Java ; new 0 { := ; { 1. { ; { ; 2. { ; ; ; 3. { ; ; { ; { ; Java main if switch case for while do-while break continue return 2.2 if if( ) else 1 2

16 16 2 if Boolean true 1 else else if for if( count < 0 ) System.err.println("Unexpected condition!!"); else if( MAX < count ) System.err.println("Too large."); else for( int i = 0 ; i < count ; i++ ) { dothejob(aparameter); if true else else if else public double sumpositive(double[] values) { double sum = 0.0; if( values.length > 1 ) // (A) for( int i = 0 ; i < values.length ; i++ ) if( values[i] > 0 ) // (B) sum += values[i]; else // (C) sum = values[0]; return sum; (C) else (A) if (C) else (B) if

17 public double sumpositive(double[] values) { double sum = 0.0; if( values.length > 1 ) { for( int i = 0 ; i < values.length ; i++ ) { if( values[i] > 0 ) { sum += values[i]; else { sum = values[0]; return sum; 2.3 : : block break continue block: {...

18 switch switch( ) { case 1:... case 2:... case 3: default:... switch case case default default case default switch switch case switch( anumber ) { case 1: System.out.println("One."); case 2: System.out.println("Two."); default: System.out.println("neither One nor Two."); 1 3 One. Two. neither One nor Two. 2 Two. neither One nor Two. 2

19 2.5. while do-while 19 break switch( anumber ) { case 1: System.out.println("One."); break; case 2: System.out.println("Two."); break; default: System.out.println("neither One nor Two."); 2.5 while do-while while( ) while while true false while false while do-while do-while do while( ); do-while trule while 2.6 for for( ; ; ) for while for continue for

20 20 2 { ; while( ) { ;, for( i = 0, j = arr.length - 1 ; i < arr.length ; i++, j-- ) { if( arr[j] ==... )... for true for(;;) 2.7 break break ; break switch for while do-while switch for while do-while

21 2.8. continue 21 public boolean searchvalue( int c ) { int x, y; boolean found = false; search: for( x = 0 ; x < Matrix.length ; x++ ) { for( y = 0 ; y < Matrix[x].length ; y++ ) { if( Matrix[x][y] == c ) { found = true; break search; //... break C goto goto break continue 2.8 continue continue ; continue for while do-while for while do-while break for while do-while for continue continue while do-while continue (B) for (A) for (C) (A) for (B) for

22 22 2 public boolean searchvalue( int c ) { int x, y; boolean found = false; search: for( x = 0 ; x < Matrix.length ; x++ ) { // (A) for( y = 0 ; y < Matrix[x].length ; y++ ) { // (B) if( Matrix[x][y] == c ) { continue search; found = true; // (C) // return return ; return return

10/ / /30 3. ( ) 11/ 6 4. UNIX + C socket 11/13 5. ( ) C 11/20 6. http, CGI Perl 11/27 7. ( ) Perl 12/ 4 8. Windows Winsock 12/11 9. JAV

10/ / /30 3. ( ) 11/ 6 4. UNIX + C socket 11/13 5. ( ) C 11/20 6. http, CGI Perl 11/27 7. ( ) Perl 12/ 4 8. Windows Winsock 12/11 9. JAV tutimura@mist.i.u-tokyo.ac.jp kaneko@ipl.t.u-tokyo.ac.jp http://www.misojiro.t.u-tokyo.ac.jp/ tutimura/sem3/ 2002 12 11 p.1/33 10/16 1. 10/23 2. 10/30 3. ( ) 11/ 6 4. UNIX + C socket 11/13 5. ( ) C 11/20