1. Javaç°å¢æ§ç¯ã®éèŠæ§
ããã°ã©ãã³ã°ã®äžçã«ã¯æ§ã ãªèšèªãååšããŸãããJavaã¯ãã®äžã§ãç¹ã«äººæ°ã®ããèšèªã®äžã€ã§ããJavaãåŠã¶äžã§ãæåã«åãçµãã¹ãã¯ãé©åãªéçºç°å¢ãæ§ç¯ããããšã§ãã
1.1 Javaãšã¯ïŒ
Javaã¯ã1990幎代åé ã«Sun Microsystemsã§éçºãããããã°ã©ãã³ã°èšèªã§ãããã®ç¹åŸŽã¯ããäžåºŠæžãã°ã©ãã§ãåãããšããã³ã³ã»ããã«ãããŸããããã¯ãJavaããã©ãããã©ãŒã ã«äŸåããªããšããç¹æ§ãæã£ãŠããããã§ããJavaã§æžãããããã°ã©ã ã¯ãWindowsãMacãLinuxãªã©ãããŸããŸãªãªãã¬ãŒãã£ã³ã°ã·ã¹ãã ã§åäœããŸãã
ãŸããJavaã¯ãªããžã§ã¯ãæåããã°ã©ãã³ã°èšèªã§ãããåå©çšæ§ãæ¡åŒµæ§ãé«ããšããç¹åŸŽãæã£ãŠããŸããããã«ããã倧èŠæš¡ãªã¢ããªã±ãŒã·ã§ã³ã®éçºããè€æ°ã®éçºè ãååããŠã®ãããžã§ã¯ãã«ãé©ããŠããŸãã
1.2 éçºç°å¢æ§ç¯ã®åœ¹å²
Javaã§ã®ããã°ã©ãã³ã°ãå§ããåã«ãé©åãªéçºç°å¢ãæ§ç¯ããããšã¯éåžžã«éèŠã§ããéçºç°å¢ãšã¯ãããã°ã©ã ãæžãããã¹ãããå®è¡ããããã®ããŒã«ããœãããŠã§ã¢ã®ã»ããã®ããšãæããŸãã
éçºç°å¢ãé©åã«æ§ç¯ããããšã§ã以äžã®ãããªã¡ãªããããããŸãïŒ
å¹ççãªã³ãŒãã£ã³ã° | é©åãªããŒã«ã䜿çšããããšã§ãã³ãŒãã®æžããããããããã°ã®å¹çãåäžããŸãã |
ãšã©ãŒã®æ©æçºèŠ | éçºç°å¢ã«çµã¿èŸŒãŸããããŒã«ã䜿çšããããšã§ãã³ãŒãã®ãšã©ãŒãæ©æã«çºèŠããä¿®æ£ããããšãã§ããŸãã |
å®å®ããåäœç°å¢ | äžè²«ããç°å¢äžã§ã®éçºã«ãããäºæããªãåäœããšã©ãŒãé²ãããšãã§ããŸãã |
ãããã®ã¡ãªããã享åããããã«ã¯ãJavaã®éçºç°å¢ãæ£ããæ§ç¯ããããšãäžå¯æ¬ ã§ãã次ã®ã»ã¯ã·ã§ã³ã§ã¯ãJavaã®éçºç°å¢ã®æ§ç¯æé ã«ã€ããŠè©³ãã解説ããŸãã
2. Javaç°å¢æ§ç¯ã®åºæ¬æé
Javaã®ããã°ã©ãã³ã°ãå§ããã«ã¯ããŸãé©åãªéçºç°å¢ãæŽããå¿ èŠããããŸãããã®ã»ã¯ã·ã§ã³ã§ã¯ãJavaã®éçºç°å¢ãæ§ç¯ããããã®åºæ¬çãªæé ã«ã€ããŠèª¬æããŸãã
2.1 JDK (Java Development Kit) ã®ããŠã³ããŒã
Javaã®éçºãè¡ãããã«ã¯ãJDK (Java Development Kit)ãå¿ èŠã§ããJDKã¯ãJavaã®ããã°ã©ã ãæžãããã®ããŒã«ãã©ã€ãã©ãªãæäŸãããã®ã§ãJavaã®å ¬åŒãµã€ãããç¡æã§ããŠã³ããŒãããããšãã§ããŸãã
ããŠã³ããŒãããéã«ã¯ã䜿çšããŠãããªãã¬ãŒãã£ã³ã°ã·ã¹ãã ã«åãããããŒãžã§ã³ãéžæããããšãéèŠã§ãããŸããææ°ã®ããŒãžã§ã³ãéžæããããšã§ãææ°ã®æ©èœãã»ãã¥ãªãã£ã¢ããããŒããå©çšããããšãã§ããŸãã
2.2 ã€ã³ã¹ããŒã«æé ã®è©³çŽ°
JDKã®ããŠã³ããŒããå®äºãããã次ã«ã€ã³ã¹ããŒã«ãè¡ããŸããã€ã³ã¹ããŒã«ã¯åºæ¬çã«ããŠã³ããŒããããã¡ã€ã«ãå®è¡ããæ瀺ã«åŸã£ãŠé²ããã ãã§ãããããã€ãã®èšå®é ç®ã«æ³šæãå¿ èŠã§ãã
ç¹ã«ãã€ã³ã¹ããŒã«å ã®ãã£ã¬ã¯ããªãã䜿çšããã¡ã¢ãªã®èšå®ãªã©ã¯ãåŸã ã®éçºã«åœ±é¿ãäžããå¯èœæ§ããããããæ éã«éžæããããšãæšå¥šãããŸãã
2.3 ç°å¢å€æ°ã®èšå®
JDKã®ã€ã³ã¹ããŒã«ãå®äºãããã次ã«ç°å¢å€æ°ã®èšå®ãè¡ããŸããç°å¢å€æ°ãšã¯ããªãã¬ãŒãã£ã³ã°ã·ã¹ãã ãããã°ã©ã ãå®è¡ããéã«åç §ããèšå®å€ã®ããšãæããŸãã
Javaã®ããã°ã©ã ãå®è¡ããããã«ã¯ãPATHãšããç°å¢å€æ°ã«JDKã®ã€ã³ã¹ããŒã«å ãè¿œå ããå¿ èŠããããŸããããã«ãããã³ãã³ãããã³ãããã¿ãŒããã«ããJavaã®ã³ãã³ããå®è¡ããããšãã§ããããã«ãªããŸãã
ç°å¢å€æ°ã®èšå®ã¯ããªãã¬ãŒãã£ã³ã°ã·ã¹ãã ã®èšå®ç»é¢ããè¡ãããšãã§ããŸããèšå®æ¹æ³ã¯ãªãã¬ãŒãã£ã³ã°ã·ã¹ãã ã«ãã£ãŠç°ãªããããé©åãªæé ãåç §ããŠèšå®ãè¡ã£ãŠãã ããã
以äžããJavaã®éçºç°å¢ãæ§ç¯ããããã®åºæ¬çãªæé ã§ãããããã®æé ãæ£ããè¡ãããšã§ãJavaã®ããã°ã©ãã³ã°ãã¹ã ãŒãºã«å§ããããšãã§ããŸãã
3. éçºããŒã«Eclipseã®ã»ããã¢ãã
Javaã®éçºç°å¢ãæŽããéãããã°ã©ã ã®ã³ãŒãã£ã³ã°ããããã°ãå¹ççã«è¡ãããã®IDEïŒçµ±åéçºç°å¢ïŒãå¿ èŠãšãªããŸãããã®äžã§ããEclipseã¯Javaéçºè ã«åºãå©çšãããŠãã人æ°ã®IDEã®äžã€ã§ãã
3.1 Eclipseãšã¯ïŒ
Eclipseã¯ããªãŒãã³ãœãŒã¹ã®çµ±åéçºç°å¢ïŒIDEïŒã§ãããJavaãã¯ãããšããå€ãã®ããã°ã©ãã³ã°èšèªã«å¯Ÿå¿ããŠããŸããEclipseã®æ倧ã®ç¹åŸŽã¯ããã©ã°ã€ã³ã¢ãŒããã¯ãã£ã«ãããŸããããã«ããããŠãŒã¶ãŒã¯å¿ èŠã«å¿ããŠæ©èœãè¿œå ããããã«ã¹ã¿ãã€ãºããããšãã§ããŸãã
ãŸããEclipseã¯ã³ãŒãã®èªåè£å®ããšã©ãŒãã§ãã¯ãªã©ãéçºè ã®çç£æ§ãåäžãããå€ãã®æ©èœãåããŠããŸããããã«ãããåå¿è ããäžçŽè ãŸã§ãå¹ åºãéçºè ãå¹ççã«ã³ãŒãã£ã³ã°ãè¡ãããšãã§ããŸãã
3.2 Eclipseã®ããŠã³ããŒããšã€ã³ã¹ããŒã«
Eclipseã®ããŠã³ããŒãã¯ãå ¬åŒãµã€ãããè¡ãããšãã§ããŸããããŠã³ããŒãããŒãžã«ã¯ãããŸããŸãªããŒãžã§ã³ãããã±ãŒãžãæäŸãããŠãããããJavaã®éçºã«é©ãããã®ãéžæããããšãéèŠã§ãã
ããŠã³ããŒããããã¡ã€ã«ãå®è¡ããããšã§ãã€ã³ã¹ããŒã«ãéå§ãããŸããã€ã³ã¹ããŒã«ã®éã«ã¯ãã€ã³ã¹ããŒã«å ã®ãã£ã¬ã¯ããªãã¯ãŒã¯ã¹ããŒã¹ã®å Žæãªã©ãããã€ãã®èšå®é ç®ãæå®ããå¿ èŠããããŸãããããã®èšå®ã¯åŸã ã®éçºã«åœ±é¿ãäžããå¯èœæ§ããããããæ éã«éžæããããšãæšå¥šãããŸãã
3.3 Javaãããžã§ã¯ãã®äœææ¹æ³
Eclipseãèµ·åãããã次ã«Javaã®ãããžã§ã¯ããäœæããŸããæ°ãããããžã§ã¯ããäœæããã«ã¯ããFileãã¡ãã¥ãŒãããNewããéžæãããJava Projectããã¯ãªãã¯ããŸãããããžã§ã¯ãåãä¿åå ã®ãã£ã¬ã¯ããªãæå®ããåŸãå¿ èŠãªèšå®ãè¡ãããããžã§ã¯ãã®äœæãå®äºããŸãã
ãããžã§ã¯ããäœæããããããœãŒã¹ã³ãŒããæžãããã®ã¯ã©ã¹ãã€ã³ã¿ãŒãã§ãŒã¹ãè¿œå ããããšãã§ããŸããEclipseã®åŒ·åãªãšãã£ã¿ã掻çšããŠãå¹ççã«ã³ãŒãã£ã³ã°ãè¡ãããšãã§ããŸãã
以äžããEclipseã®ã»ããã¢ãããšJavaãããžã§ã¯ãã®äœææ¹æ³ã«ã€ããŠã®åºæ¬çãªæé ã§ãããããã®æé ãæ£ããè¡ãããšã§ãJavaã®éçºãã¹ã ãŒãºã«é²ããããšãã§ããŸãã
4. ãããããã©ãã«ãšãã®å¯ŸåŠæ³
Javaã®éçºç°å¢ãæ§ç¯ããéãããŸããŸãªãã©ãã«ã«ééããããšããããŸãããã®ã»ã¯ã·ã§ã³ã§ã¯ãJavaã®ç°å¢æ§ç¯ãEclipseã®äœ¿çšäžã«ããçºçãããã©ãã«ãšããããã®å¯ŸåŠæ³ã«ã€ããŠèª¬æããŸãã
4.1 ã€ã³ã¹ããŒã«ãšã©ãŒã®å¯ŸåŠæ³
JavaãEclipseã®ã€ã³ã¹ããŒã«äžã«ãšã©ãŒãçºçããããšããããŸãããã®åå ã¯æ§ã ã§ããã以äžã¯ãããããšã©ãŒãšãã®å¯ŸåŠæ³ã§ãã
ã»ãã£ã¹ã¯å®¹éäžè¶³ïŒ ã€ã³ã¹ããŒã«ã«å¿ èŠãªãã£ã¹ã¯å®¹éãäžè¶³ããŠããå Žåãã€ã³ã¹ããŒã«ã¯å€±æããŸãããã®å ŽåãäžèŠãªãã¡ã€ã«ãåé€ããŠç©ºã容éãå¢ããããã€ã³ã¹ããŒã«å ã®ãã£ã¬ã¯ããªãå€æŽããŠãã ããã
ã»ãããã¯ãŒã¯ã®åé¡ïŒ ã€ã³ã¿ãŒãããæ¥ç¶ãäžå®å®ãªå ŽåãããŠã³ããŒãäžã«ãšã©ãŒãçºçããããšããããŸããæ¥ç¶ç°å¢ã確èªããå床ããŠã³ããŒããè©Šã¿ãŠãã ããã
4.2 ç°å¢å€æ°ã®ãã©ãã«ã·ã¥ãŒãã£ã³ã°
Javaã®ã³ãã³ããå®è¡ããéãç°å¢å€æ°ã®èšå®ãæ£ãããªããšãšã©ãŒãçºçããŸããç¹ã«PATHå€æ°ã®èšå®ã¯ãJavaã®ã³ãã³ããæ£ããèªèããããã«éèŠã§ãã
ãšã©ãŒãçºçããå ŽåããŸãç°å¢å€æ°ã®èšå®ã確èªããŠãã ãããæ£ãããã¹ãèšå®ãããŠããããäœåãªæåãã¹ããŒã¹ãå ¥ã£ãŠããªããããã§ãã¯ããããšãéèŠã§ãã
4.3 Eclipseã®èµ·ååé¡ãšè§£æ±ºç
Eclipseãèµ·åããéãæ§ã ãªåé¡ãçºçããããšããããŸãã以äžã¯ãããããèµ·ååé¡ãšãã®å¯ŸåŠæ³ã§ãã
ã»ã¯ãŒã¯ã¹ããŒã¹ã®åé¡ïŒ Eclipseã¯æå®ããã¯ãŒã¯ã¹ããŒã¹ã«ãããžã§ã¯ããèšå®ãä¿åããŸããã¯ãŒã¯ã¹ããŒã¹ã®ãã£ã¬ã¯ããªãååšããªãããŸãã¯ã¢ã¯ã»ã¹æš©éããªãå ŽåãEclipseã®èµ·åã«å€±æããŸããã¯ãŒã¯ã¹ããŒã¹ã®å Žæãã¢ã¯ã»ã¹æš©éã確èªããå¿ èŠã«å¿ããŠå€æŽããŠãã ããã
ã»JavaããŒãžã§ã³ã®äžäžèŽïŒ Eclipseã¯ç¹å®ã®JavaããŒãžã§ã³ã§åäœããŸããã€ã³ã¹ããŒã«ãããŠããJavaã®ããŒãžã§ã³ãšãEclipseãèŠæ±ããããŒãžã§ã³ãç°ãªãå Žåãèµ·åã«å€±æããããšããããŸãããã®å Žåãé©åãªJavaããŒãžã§ã³ãã€ã³ã¹ããŒã«ããããEclipseã®ããŒãžã§ã³ãå€æŽããŠãã ããã
ãããã®ãã©ãã«ã¯ãåããŠJavaã®éçºç°å¢ãæ§ç¯ããéã«ããçºçããŸããããããæ£ããæé ãšå¯ŸåŠæ³ãç¥ã£ãŠããã°ãã¹ã ãŒãºã«åé¡ã解決ããããšãã§ããŸãã
5. Javaéçºã®ãã¹ããã©ã¯ãã£ã¹
Javaã®éçºãè¡ãéãå質ã®é«ãã³ãŒããæžãããã®ãã¹ããã©ã¯ãã£ã¹ãååšããŸãããã®ã»ã¯ã·ã§ã³ã§ã¯ãJavaéçºã§ã®ã³ãŒãã®æžãæ¹ããããã°æ¹æ³ãä¿å®æ§ã®åäžã«ã€ããŠã®ãã¹ããã©ã¯ãã£ã¹ã玹ä»ããŸãã
5.1 ã³ãŒãã®æžãæ¹ã®åºæ¬
è¯ãã³ãŒããæžãããã®åºæ¬çãªååãšããŠãå¯èªæ§ãåå©çšæ§ãæ¡åŒµæ§ãæããããŸãã以äžã¯ããããã®ååãå®çŸããããã®åºæ¬çãªã¬ã€ãã©ã€ã³ã§ãã
ã»å€æ°ãã¡ãœããã®åœåã¯ããã®åœ¹å²ãæ©èœãæ確ã«ç€ºããã®ãéžã¶ããšãéèŠã§ãã
ã»ã³ãŒãã®åé·ãªéšåã¯é¿ããå¿
èŠãªåŠçãç°¡æœã«è¡šçŸããããšãå¿ãããŠãã ããã
ã»ã³ã¡ã³ããé©åã«äœ¿çšããŠãã³ãŒãã®ç®çãåäœã説æããããšã§ãä»ã®éçºè
ã«ãç解ããããããŸãã
5.2 å¹ççãªãããã°æ¹æ³
ããã°ã©ã ã«ã¯å¿ ããšèšã£ãŠããã»ã©ãã°ãçºçããŸããå¹ççãªãããã°æ¹æ³ãç¥ã£ãŠããããšã§ãåé¡ã®åå ãè¿ éã«ç¹å®ããä¿®æ£ããããšãã§ããŸãã
ã»åäœãã¹ããå©çšããŠãå°ããªåäœã§ã®åäœã確èªããããšãæšå¥šãããŸãã
ã»ãããã°ããŒã«ããã°åºåã掻çšããŠãåé¡ã®çºçç®æãåå ãç¹å®ããŸãã
ã»åé¡ã®åçŸæé ãæ確ã«ããåãåé¡ãåçºããªãããã«æ³šæãæã£ãŠãã ããã
5.3 ã³ãŒãã®ä¿å®æ§ãé«ããããã®ãã³ã
é·æçã«å®å®ããŠåäœãããœãããŠã§ã¢ãéçºããããã«ã¯ãã³ãŒãã®ä¿å®æ§ãé«ããããšãéèŠã§ãã以äžã¯ãä¿å®æ§ãé«ããããã®ãã³ãã§ãã
ã»ãªãã¡ã¯ã¿ãªã³ã°ãå®æçã«è¡ããã³ãŒãã®æ§é ãèšèšãæ¹åããŠãã ããã
ã»æè¡çè² åµãç©ã¿éããªãããã«ãåé¡ç¹ãæ¹åç¹ãæ©æã«å¯Ÿå¿ããããšãæšå¥šãããŸãã
ã»ããã¥ã¡ã³ããŒã·ã§ã³ãæŽåããã·ã¹ãã ã®æŠèŠãèšèšææ³ãå€æŽå±¥æŽãªã©ãèšé²ããŠããããšã§ãåŸã
ã®ä¿å®äœæ¥ãå©ããŸãã
以äžããJavaéçºã®ãã¹ããã©ã¯ãã£ã¹ã«é¢ããåºæ¬çãªã¬ã€ãã©ã€ã³ã§ãããããã®ãã³ããåèã«ãå質ã®é«ãJavaã®ãœãããŠã§ã¢éçºãç®æããŠãã ããã
6. ãŸãšããšæ¬¡ã®ã¹ããã
ãã®èšäºã§ã¯ãJavaç°å¢æ§ç¯ã®åºæ¬çãªæé ããã¹ããã©ã¯ãã£ã¹ã«ã€ããŠçŽ¹ä»ããŸãããJavaã®éçºç°å¢ãæŽããããšã¯ãå¹ççãªããã°ã©ãã³ã°ãè¡ãããã«éèŠã§ããæé©ãªç°å¢ãæ§ç¯ããå質ã®é«ãã³ãŒããæžãããã«ã以äžã®ãã€ã³ããå確èªããŸãããã
6.1 ç°å¢æ§ç¯ã®ãã€ã³ãã®å確èª
ç°å¢æ§ç¯ã®éã«éèŠãªãã€ã³ãããŸãšããŠãããŸãã
1. JDKã®ããŠã³ããŒãïŒ å ¬åŒãµã€ãããé©åãªããŒãžã§ã³ã®JDKãããŠã³ããŒãããã€ã³ã¹ããŒã«ããŸãã
2. Eclipseã®ã€ã³ã¹ããŒã«ïŒ EclipseãããŠã³ããŒãããŠã€ã³ã¹ããŒã«ããé©åãªèšå®ãè¡ããŸãã
3. ãããžã§ã¯ãã®äœæïŒ Eclipseã§æ°ããJavaãããžã§ã¯ããäœæããã³ãŒãã£ã³ã°ãå§ããŸãã
6.2 JavaåŠç¿ã®ããã®ãªãœãŒã¹çŽ¹ä»
Javaã®åŠç¿ãæ·±ããããã«ã以äžã®ãªãœãŒã¹ã掻çšããããšãããããããŸãã
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