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綰у埆錛?鍒濈駭 David WendtWebSphere Development Research Triangle Park, NC 1999 騫?5 鏈?01 鏃?/p> 鏈枃涓哄湪 32 浣?Windows 騫沖彴涓婂疄鐜?Java 鏈湴鏂規(guī)硶鎻愪緵浜嗗疄鐢ㄧ殑紺轟緥銆佹楠ゅ拰鍑嗗垯銆傝繖浜涚ず渚嬪寘鎷紶閫掑拰榪斿洖甯哥敤鐨勬暟鎹被鍨嬨? 鏈枃鎻愪緵璋冪敤鏈湴 C 浠g爜鐨?Java 浠g爜紺轟緥錛屽寘鎷紶閫掑拰榪斿洖鏌愪簺甯哥敤鐨勬暟鎹被鍨嬨傛湰鍦版柟娉曞寘鍚湪鐗瑰畾浜庡鉤鍙扮殑鍙墽琛屾枃浠朵腑銆傚氨鏈枃涓殑紺轟緥鑰岃█錛屾湰鍦版柟娉曞寘鍚湪 Windows 32 浣嶅姩鎬侀摼鎺ュ簱 (DLL) 涓?/p> 涓嶈繃鎴戣鎻愰啋鎮(zhèn)紝瀵?Java 澶栭儴鐨勮皟鐢ㄩ氬父涓嶈兘縐繪鍒板叾浠栧鉤鍙頒笂錛屽湪 applet 涓繕鍙兘寮曞彂瀹夊叏寮傚父銆傚疄鐜版湰鍦頒唬鐮佸皢浣挎?zhèn)ㄧ?Java 搴旂敤紼嬪簭鏃犳硶閫氳繃 100% 綰?Java 嫻嬭瘯銆備絾鏄紝濡傛灉蹇呴』鎵ц鏈湴璋冪敤錛屽垯瑕佽冭檻鍑犱釜鍑嗗垯錛?/p>
瀵逛簬璋冪敤 C 鍑芥暟鐨?Java 鏂規(guī)硶錛屽繀欏誨湪 Java 綾諱腑澹版槑涓涓湰鍦版柟娉曘傚湪鏈儴鍒嗙殑鎵鏈夌ず渚嬩腑錛屾垜浠皢鍒涘緩涓涓悕涓?MyNative 鐨勭被錛屽茍閫愭鍦ㄥ叾涓姞鍏ユ柊鐨勫姛鑳姐傝繖寮鴻皟浜嗕竴縐嶆濇兂錛屽嵆灝嗘湰鍦版柟娉曢泦涓湪鍗曚釜綾諱腑錛屼互渚垮皢浠ュ悗鎵闇鐨勭Щ妞嶅伐浣滃噺鍒版渶灝戙?/p>
鍦ㄧ涓涓ず渚嬩腑錛屾垜浠皢涓変釜甯哥敤鍙傛暟綾誨瀷浼犻掔粰鏈湴鍑芥暟錛?String銆?int鍜?boolean 銆傛湰渚嬭鏄庡湪鏈湴 C 浠g爜涓浣曞紩鐢ㄨ繖浜涘弬鏁般?
璇鋒敞鎰忥紝鏈湴鏂規(guī)硶琚0鏄庝負(fù)涓撶敤鐨勶紝騫跺垱寤轟簡涓涓寘瑁呮柟娉曠敤浜庡叕鐢ㄧ洰鐨勩傝繖榪涗竴姝ュ皢鏈湴鏂規(guī)硶鍚屼唬鐮佺殑鍏朵綑閮ㄥ垎闅旂寮鏉ワ紝浠庤屽厑璁?dāng)R拡瀵規(guī)墍闇鐨勫鉤鍙板瀹冭繘琛屼紭鍖栥?static瀛愬彞鍔犺澆鍖呭惈鏈湴鏂規(guī)硶瀹炵幇鐨?DLL銆? 涓嬩竴姝ユ槸鐢熸垚 C 浠g爜鏉ュ疄鐜?showParms0 鏂規(guī)硶銆傛鏂規(guī)硶鐨?C 鍑芥暟鍘熷瀷鏄氳繃瀵?.class 鏂囦歡浣跨敤 javah 瀹炵敤紼嬪簭鏉ュ垱寤虹殑錛岃?.class 鏂囦歡鏄氳繃緙栬瘧 MyNative.java 鏂囦歡鐢熸垚鐨勩傝繖涓疄鐢ㄧ▼搴忓彲鍦?JDK 涓壘鍒般備笅闈㈡槸 javah 鐨勭敤娉曪細
榪欏皢鐢熸垚涓涓?MyNative.h 鏂囦歡錛屽叾涓寘鍚竴涓湰鍦版柟娉曞師鍨嬶紝濡備笅鎵紺猴細
絎竴涓弬鏁版槸璋冪敤 JNI 鏂規(guī)硶鏃朵嬌鐢ㄧ殑 JNI Environment 鎸囬拡銆傜浜屼釜鍙傛暟鏄寚鍚戝湪姝?Java 浠g爜涓疄渚嬪寲鐨?Java 瀵硅薄 MyNative 鐨勪竴涓彞鏌勩傚叾浠栧弬鏁版槸鏂規(guī)硶鏈韓鐨勫弬鏁般傝娉ㄦ剰錛孧yNative.h 鍖呮嫭澶存枃浠?jni.h銆俲ni.h 鍖呭惈 JNI API 鍜屽彉閲忕被鍨嬶紙鍖呮嫭jobject銆乯string銆乯int銆乯boolean錛岀瓑絳夛級鐨勫師鍨嬪拰鍏朵粬澹版槑銆?/p> 鏈湴鏂規(guī)硶鏄湪鏂囦歡 MyNative.c 涓敤 C 璇█瀹炵幇鐨勶細
JNI API錛孏etStringUTFChars錛岀敤鏉ユ牴鎹?Java 瀛楃涓叉垨 jstring 鍙傛暟鍒涘緩 C 瀛楃涓層傝繖鏄繀闇鐨勶紝鍥犱負(fù)鍦ㄦ湰鍦頒唬鐮佷腑涓嶈兘鐩存帴璇誨彇 Java 瀛楃涓詫紝鑰屽繀欏誨皢鍏惰漿鎹負(fù) C 瀛楃涓叉垨 Unicode銆傛湁鍏寵漿鎹?Java 瀛楃涓茬殑璇︾粏淇℃伅錛岃鍙傞槄鏍囬涓?NLS Strings and JNI 鐨勪竴綃囪鏂囥備絾鏄紝jboolean 鍜?jint 鍊煎彲浠ョ洿鎺ヤ嬌鐢ㄣ?/p> MyNative.dll 鏄氳繃緙栬瘧 C 婧愭枃浠跺垱寤虹殑銆備笅闈㈢殑緙栬瘧璇彞浣跨敤 Microsoft Visual C++ 緙栬瘧鍣細
鍏朵腑 c:\jdk1.1.6 鏄?JDK 鐨勫畨瑁呰礬寰勩?/p> MyNative.dll 宸插垱寤哄ソ錛岀幇鍦ㄥ氨鍙皢鍏剁敤浜?MyNative 綾諱簡銆?
褰撹繍琛岃繖涓?Java 搴旂敤紼嬪簭鏃訛紝璇風(fēng)‘淇?MyNative.dll 浣嶄簬 Windows 鐨?PATH 鐜鍙橀噺鎵鎸囧畾鐨勮礬寰勪腑鎴栧綋鍓嶇洰褰曚笅銆傚綋鎵ц姝?Java 紼嬪簭鏃訛紝濡傛灉鏈壘鍒拌繖涓?DLL錛屾?zhèn)ㄥ彲鑳戒細鐪嬪堫C互涓嬬殑娑堟伅錛?/p>
榪欐槸鍥犱負(fù) static 瀛愬彞鏃犳硶鍔犺澆榪欎釜 DLL錛屾墍浠ュ湪鍒濆鍖?MyNative 綾繪椂寮曞彂寮傚父銆侸ava 瑙i噴鍣ㄥ鐞嗚繖涓紓甯革紝騫舵姤鍛婁竴涓竴鑸敊璇紝鎸囧嚭鎵句笉鍒拌繖涓被銆? 濡傛灉姝?Java 紼嬪簭瀹屾垚榪愯錛屽氨浼氳緭鍑轟互涓嬪唴瀹癸細
鏈緥灝嗚鏄庡浣曞湪鏈湴鏂規(guī)硶涓疄鐜拌繑鍥炰唬鐮併?
鍏敤鐨?hypotenuse 鏂規(guī)硶璋冪敤鏈湴鏂規(guī)硶 hypotenuse0 鏉ユ牴鎹紶閫掔殑鍙傛暟璁$畻鍊鹼紝騫跺皢緇撴灉浣滀負(fù)涓涓暣鏁拌繑鍥炪傝繖涓柊鏈湴鏂規(guī)硶鐨勫師鍨嬫槸浣跨敤 javah 鐢熸垚鐨勩傝娉ㄦ剰錛屾瘡嬈¤繍琛岃繖涓疄鐢ㄧ▼搴忔椂錛屽畠?yōu)畣鑷姩瑕嗙洊褰撳墠鐩綍涓?MyNative.h銆傛寜浠ヤ笅鏂瑰紡鎵ц javah錛?/p>
鐢熸垚鐨?MyNative.h 鐜板湪鍖呭惈 hypotenuse0 鍘熷瀷錛屽涓嬫墍紺猴細
璇ユ柟娉曟槸鍦?MyNative.c 婧愭枃浠朵腑瀹炵幇鐨勶紝濡備笅鎵紺猴細
鍐嶆璇鋒敞鎰忥紝jint 鍜?int 鍊兼槸鍙簰鎹㈢殑銆?
鐜板湪鎵ц java MyNative 灝嗚緭鍑?5 鍜?15 浣滀負(fù)鏂滆竟鐨勫箋?/p> 紺轟緥 3 -- 闈欐佹柟娉?/strong> 鎮(zhèn)ㄥ彲鑳藉湪涓婇潰鐨勭ず渚嬩腑宸茬粡娉ㄦ剰鍒幫紝瀹炰緥鍖栫殑 MyNative 瀵硅薄鏄病蹇呰鐨勩傚疄鐢ㄦ柟娉曢氬父涓嶉渶瑕佸疄闄呯殑瀵硅薄錛岄氬父閮藉皢瀹冧滑鍒涘緩涓洪潤鎬佹柟娉曘傛湰渚嬭鏄庡浣曠敤涓涓潤鎬佹柟娉曞疄鐜頒笂闈㈢殑紺轟緥銆傛洿鏀?MyNative.java 涓殑鏂規(guī)硶絳懼悕錛屼互浣垮畠浠垚涓洪潤鎬佹柟娉曪細
鐜板湪榪愯 javah 涓?hypotenuse0鍒涘緩涓涓柊鍘熷瀷錛岀敓鎴愮殑鍘熷瀷濡備笅鎵紺猴細
C 婧愪唬鐮佷腑鐨勬柟娉曠鍚嶅彉浜嗭紝浣嗕唬鐮佽繕淇濇寔鍘熸牱錛?/p>
鏈川涓婏紝jobject 鍙傛暟宸插彉涓?jclass 鍙傛暟銆傛鍙傛暟鏄寚鍚?MyNative.class 鐨勪竴涓彞鏌勩俶ain 鏂規(guī)硶鍙洿鏀逛負(fù)浠ヤ笅褰㈠紡錛?/p>
鍥犱負(fù)鏂規(guī)硶鏄潤鎬佺殑錛屾墍浠ヨ皟鐢ㄥ畠涓嶉渶瑕佸疄渚嬪寲 MyNative 瀵硅薄銆傛湰鏂囧悗闈㈢殑紺轟緥灝嗕嬌鐢ㄩ潤鎬佹柟娉曘?/p> 紺轟緥 4 -- 浼犻掓暟緇?/strong> 鏈緥璇存槑濡備綍浼犻掓暟緇勫瀷鍙傛暟銆傛湰渚嬩嬌鐢ㄤ竴涓熀鏈被鍨嬶紝boolean錛屽茍灝嗘洿鏀規(guī)暟緇勫厓绱犮備笅涓涓ず渚嬪皢璁塊棶 String錛堥潪鍩烘湰綾誨瀷錛夋暟緇勩傚皢涓嬮潰鐨勬柟娉曟坊鍔犲埌 MyNative.java 婧愪唬鐮佷腑錛?
鍦ㄦ湰渚嬩腑錛屽竷?yōu)當(dāng)鍨嬫暟缁勮鍒濆鍖栦?true錛屾湰鍦版柟娉曞皢鎶婄壒瀹氱殑鍏冪礌璁劇疆涓?false銆傚悓鏃訛紝鍦?Java 婧愪唬鐮佷腑錛屾垜浠彲浠ユ洿鏀?main 浠ヤ嬌鍏跺寘鍚祴璇曚唬鐮侊細
鍦ㄧ紪璇戞簮浠g爜騫舵墽琛?javah 浠ュ悗錛孧yNative.h 澶存枃浠跺寘鍚互涓嬬殑鍘熷瀷錛?/p>
璇鋒敞鎰忥紝甯冨皵鍨嬫暟緇勬槸浣滀負(fù)鍗曚釜鍚嶄負(fù) jbooleanArray 鐨勭被鍨嬪垱寤虹殑銆?
鎸囧悜甯冨皵鍨嬫暟緇勭殑鎸囬拡鍙互浣跨敤 GetBooleanArrayElements 鑾峰緱銆? 紺轟緥 5 -- 浼犻?Java String 鏁扮粍 鏈緥灝嗛氳繃鏈甯哥敤鐨勯潪鍩烘湰綾誨瀷錛孞ava String錛岃鏄庡浣曡闂潪鍩烘湰瀵硅薄鐨勬暟緇勩傚瓧絎︿覆鏁扮粍琚紶閫掔粰鏈湴鏂規(guī)硶錛岃屾湰鍦版柟娉曞彧鏄皢瀹冧滑鏄劇ず鍒版帶鍒跺彴涓娿?
騫跺湪
鏈湴鏂規(guī)硶鍒嗗埆璁塊棶姣忎釜鍏冪礌錛屽叾瀹炵幇濡備笅鎵紺恒?/p>
鏁扮粍鍏冪礌鍙互閫氳繃 GetObjectArrayElement 璁塊棶銆? 紺轟緥 6 -- 榪斿洖 Java String 鏁扮粍 鏈鍚庝竴涓ず渚嬭鏄庡浣曞湪鏈湴浠g爜涓垱寤轟竴涓瓧絎︿覆鏁扮粍騫跺皢瀹冭繑鍥炵粰 Java 璋冪敤鑰呫侻yNative.java 涓坊鍔犱簡浠ヤ笅鍑犱釜鏂規(guī)硶錛?/p>
鏇存敼
瀹炵幇鐨勬湰鍦版柟娉曡繑鍥炰簲涓瓧絎︿覆銆?/p>
瀛楃涓叉暟緇勬槸閫氳繃璋冪敤 NewObjectArray 鍒涘緩鐨勶紝鍚屾椂浼犻掍簡 String 綾誨拰鏁扮粍闀垮害涓や釜鍙傛暟銆侸ava String 鏄嬌鐢?NewStringUTF 鍒涘緩鐨勩係tring 鍏冪礌鏄嬌鐢?SetObjectArrayElement 瀛樺叆鏁扮粍涓殑銆?/p>
鐜板湪鎮(zhèn)ㄥ凡緇忎負(fù)鎮(zhèn)ㄧ殑搴旂敤紼嬪簭鍒涘緩浜嗕竴涓湰鍦?DLL錛屼絾鍦ㄨ皟璇曟椂榪樿鐗㈣浠ヤ笅鍑犵偣銆傚鏋滀嬌鐢?Java 璋冭瘯鍣?java_g.exe錛屽垯榪橀渶瑕佸垱寤?DLL 鐨勪竴涓?#8220;璋冭瘯”鐗堟湰銆傝繖鍙槸琛ㄧず蹇呴』鍒涘緩鍚屽悕浣嗗甫鏈変竴涓?_g 鍚庣紑鐨?DLL 鐗堟湰銆傚氨 MyNative.dll 鑰岃█錛屼嬌鐢?java_g.exe 瑕佹眰鍦?Windows 鐨?PATH 鐜鎸囧畾鐨勮礬寰勪腑鏈変竴涓?MyNative_g.dll 鏂囦歡銆傚湪澶у鏁版儏鍐典笅錛岃繖涓?DLL 鍙互閫氳繃灝嗗師鏂囦歡閲嶅懡鍚嶆垨澶嶅埗涓哄叾鍚嶇О甯︾紑 _g 鐨勬枃浠躲?/p> 鐜板湪錛孞ava 璋冭瘯鍣ㄤ笉鍏佽鎮(zhèn)ㄨ繘鍏ユ湰鍦頒唬鐮侊紝浣嗘?zhèn)ㄥ彲浠ュ?Java 鐜澶栦嬌鐢?C 璋冭瘯鍣紙濡?Microsoft Visual C++錛夎皟璇曟湰鍦版柟娉曘傞鍏堝皢婧愭枃浠跺鍏ヤ竴涓」鐩腑銆?
灝嗛厤緗緗負(fù)浠ヨ皟璇曟ā寮忕紪璇?DLL銆傚湪 Project Settings 涓殑 Debug 涓嬶紝灝嗗彲鎵ц鏂囦歡璁劇疆涓?java.exe錛堟垨鑰?java_g.exe錛屼絾瑕佺‘淇濇?zhèn)ㄧ敓鎴愪簡涓涓?_g.dll 鏂囦歡錛夈傜▼搴忓弬鏁板寘鎷寘鍚?main 鐨勭被鍚嶃傚鏋滃湪 DLL 涓緗簡鏂偣錛屽垯褰撹皟鐢ㄦ湰鍦版柟娉曟椂錛屾墽琛屽皢鍦ㄩ傚綋鐨勫湴鏂瑰仠姝€?/p> 涓嬮潰鏄緗竴涓?Visual C++ 6.0 欏圭洰鏉ヨ皟璇曟湰鍦版柟娉曠殑姝ラ銆?/p>
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![]() 褰撴墽琛岃繖涓▼搴忔椂錛屽拷鐣?#8220;鍦?java.exe 涓壘涓嶅埌浠諱綍璋冭瘯淇℃伅”鐨勬秷鎭傚綋璋冪敤鏈湴鏂規(guī)硶鏃訛紝鍦?C 浠g爜涓緗殑浠諱綍鏂偣灝嗗湪閫傚綋鐨勫湴鏂瑰仠姝?Java 紼嬪簭鐨勬墽琛屻?/p>
JNI 鏂規(guī)硶鍜?C++ 涓婇潰榪欎簺紺轟緥璇存槑浜嗗浣曞湪 C 婧愭枃浠朵腑浣跨敤 JNI 鏂規(guī)硶銆傚鏋滀嬌鐢?C++錛屽垯璇峰皢鐩稿簲鏂規(guī)硶鐨勬牸寮忎粠錛?/p>
鏇存敼涓猴細
鍦?C++ 涓紝JNI 鍑芥暟琚湅浣滄槸 JNIEnv 綾葷殑鎴愬憳鏂規(guī)硶銆?/p> 瀛楃涓插拰鍥藉璇█鏀寔 鏈枃涓嬌鐢ㄧ殑鎶鏈敤 UTF 鏂規(guī)硶鏉ヨ漿鎹㈠瓧絎︿覆銆備嬌鐢ㄨ繖浜涙柟娉曞彧鏄負(fù)浜嗘柟渚胯搗瑙侊紝濡傛灉搴旂敤紼嬪簭闇瑕佸浗瀹惰璦鏀寔 (NLS)錛屽垯涓嶈兘浣跨敤榪欎簺鏂規(guī)硶銆傛湁鍏沖湪 Windows 鍜?NLS 鐜涓鐞?Java 瀛楃涓叉紜柟娉曪紝璇峰弬鏍囬涓?NLS Strings and JNI 鐨勪竴綃囪鏂囥?/p>
鏈枃鎻愪緵鐨勭ず渚嬬敤鏈甯哥敤鐨勬暟鎹被鎹紙濡?jint 鍜?jstring錛夎鏄庝簡濡備綍瀹炵幇鏈湴鏂規(guī)硶錛屽茍璁ㄨ浜?Windows 鐗瑰畾鐨勫嚑涓棶棰橈紝濡傛樉紺哄瓧絎︿覆銆傛湰鏂囨彁渚涚殑紺轟緥騫舵湭鍖呮嫭鍏ㄩ儴 JNI錛孞NI 榪樺寘鎷叾浠栧弬鏁扮被鍨嬶紝濡?jfloat銆乯double銆乯short銆乯byte 鍜?jfieldID錛屼互鍙婄敤鏉ュ鐞嗚繖浜涚被鍨嬬殑鏂規(guī)硶銆傛湁鍏寵繖涓富棰樼殑璇︾粏淇℃伅錛岃鍙傞槄 Sun Microsystems 鎻愪緵鐨?Java 鏈湴鎺ュ彛瑙勮寖銆?/p>
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2銆佽嚜瀹氫箟FileFilter
JDK娌℃湁鎻愪緵榛樿鐨勬枃浠惰繃婊ゅ櫒錛屼絾鎻愪緵浜嗚繃婊ゅ櫒鐨勬娊璞¤秴綾伙紝鎴戜滑鍙互緇ф壙瀹冦?/p>
import javax.swing.filechooser.FileFilter;
public final class PictureFileFilter extends FileFilter {
private String extension;
private String description;
public PictureFileFilter(String extension, String description) {
super();
this.extension = extension;
this.description = description;
}
public boolean accept(File f) {
if (f != null) {
if (f.isDirectory()) {
return true;
}
String extension = getExtension(f);
if (extension != null && extension.equalsIgnoreCase(this.extension)) {
return true;
}
}
return false;
}
public String getDescription() {
return description;
}
private String getExtension(File f) {
if (f != null) {
String filename = f.getName();
int i = filename.lastIndexOf('.');
if (i > 0 && i < filename.length() - 1) {
return filename.substring(i + 1).toLowerCase();
}
}
return null;
}
}
鍏跺疄涓昏灝辨槸accept(File f)鍑芥暟銆備笂渚嬩腑鍙湁涓涓繃婊ゅ櫒錛屽涓繃婊ゅ櫒鍙弬鑰僇DK鐩綍涓?#8220;demo\jfc\FileChooserDemo\src”涓殑“ExampleFileFilter.java”
3銆佸閫?/p>
鍦ㄥ熀鏈敤娉曚腑錛岃緗?/p>
c.setMultiSelectionEnabled(true);
鍗沖彲瀹炵幇鏂囦歡鐨勫閫夈?/p>
璇誨彇閫夋嫨鐨勬枃浠舵椂闇浣跨敤
File[] files = c.getSelectedFiles();
4銆侀夋嫨鐩綍
鍒╃敤榪欎釜鎵撳紑瀵硅瘽妗嗭紝涓嶄粎鍙互閫夋嫨鏂囦歡錛岃繕鍙互閫夋嫨鐩綍銆?/p>
鍏跺疄錛屽璇濇鏈変竴涓狥ileSelectionMode灞炴э紝鍏墮粯璁ゅ間負(fù)“JFileChooser.FILES_ONLY”錛屽彧闇瑕佸皢鍏朵慨鏀逛負(fù)“JFileChooser.DIRECTORIES_ONLY”鍗沖彲銆?/p>
JFileChooser c = new JFileChooser();
c.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
c.setDialogTitle("Select path to save");
int result = c.showOpenDialog(PrintDatetime.this);
if (result == JFileChooser.APPROVE_OPTION) {
String path = c.getSelectedFile().getAbsolutePath());
...
}