{"id":9544,"date":"2024-08-27T11:10:36","date_gmt":"2024-08-27T02:10:36","guid":{"rendered":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/?p=9544"},"modified":"2024-08-27T11:10:36","modified_gmt":"2024-08-27T02:10:36","slug":"java-file-stream-%e3%81%a8-filechannel-%e3%81%ae%e9%80%9f%e5%ba%a6%e6%af%94%e8%bc%83","status":"publish","type":"post","link":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/archives\/9544","title":{"rendered":"java File Stream \u3068 FileChannel \u306e\u901f\u5ea6\u6bd4\u8f03"},"content":{"rendered":"
\"\"<\/div>\n

\u3053\u3093\u306b\u3061\u308f\u3001\u732b\u597d\u304d\u30ea\u30fc\u30de\u30f3\u306e\u307b\u3052PG\u3067\u3059\u3002
\n\u4eca\u66f4\u306a\u304c\u3089FileChannel<\/strong>\u304c\u3069\u308c\u304f\u3089\u3044\u306e\u3082\u306e\u304b\u5206\u304b\u3089\u306a\u304b\u3063\u305f\u306e\u3067\u8abf\u3079\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n

\"\"<\/p>\n

\u25c7\u305d\u308c\u305e\u308c\u306e\u7279\u5fb4<\/h2>\n

Java\u306b\u306f\u3001\u30d5\u30a1\u30a4\u30eb\u64cd\u4f5c\u306b\u4f7f\u7528\u3067\u304d\u308b\u3055\u307e\u3056\u307e\u306a\u30af\u30e9\u30b9\u3068API\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u4e2d\u3067\u3082\u3001FileStream\u3068FileChannel\u306f\u30d5\u30a1\u30a4\u30eb\u306e\u8aad\u307f\u66f8\u304d\u306b\u4f7f\u7528\u3055\u308c\u308b\u4e3b\u8981\u306a\u30af\u30e9\u30b9\u3067\u3059\u3002<\/p>\n

FileInputStream\/FileOutputStream (\u30d5\u30a1\u30a4\u30eb\u30b9\u30c8\u30ea\u30fc\u30e0):<\/h4>\n

FileInputStream\u3068FileOutputStream\u306f\u3001\u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u30d5\u30a1\u30a4\u30eb\u3092\u8aad\u307f\u66f8\u304d\u3059\u308b\u305f\u3081\u306e\u30b9\u30c8\u30ea\u30fc\u30e0\u30af\u30e9\u30b9\u3067\u3059\u3002\u3053\u308c\u3089\u306e\u30af\u30e9\u30b9\u306f\u3001\u30b7\u30f3\u30d7\u30eb\u3067\u76f4\u611f\u7684\u306a\u65b9\u6cd5\u3067\u30d5\u30a1\u30a4\u30eb\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002\u8aad\u307f\u8fbc\u3093\u3060\u308a\u66f8\u304d\u8fbc\u3093\u3060\u308a\u3059\u308b\u30c7\u30fc\u30bf\u306f\u3001\u30d0\u30a4\u30c8\u914d\u5217\u3068\u3057\u3066\u51e6\u7406\u3055\u308c\u307e\u3059\u3002<\/p>\n

FileChannel (\u30d5\u30a1\u30a4\u30eb\u30c1\u30e3\u30cd\u30eb):<\/h4>\n

FileChannel\u306f\u3001NIO\uff08New Input\/Output\uff09\u30d1\u30c3\u30b1\u30fc\u30b8\u3067\u63d0\u4f9b\u3055\u308c\u308b\u30af\u30e9\u30b9\u3067\u3059\u3002\u30d5\u30a1\u30a4\u30eb\u306e\u8aad\u307f\u66f8\u304d\u3092\u884c\u3046\u305f\u3081\u306e\u9ad8\u5ea6\u306a\u5236\u5fa1\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002FileChannel\u306f\u3001ByteBuffer\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u306e\u8aad\u307f\u66f8\u304d\u3092\u884c\u3044\u307e\u3059\u3002\u307e\u305f\u3001\u975e\u540c\u671fIO\u3084\u30e1\u30e2\u30ea\u30de\u30c3\u30d4\u30f3\u30b0\u30d5\u30a1\u30a4\u30eb\u306a\u3069\u306e\u9ad8\u5ea6\u306a\u6a5f\u80fd\u3082\u63d0\u4f9b\u3055\u308c\u307e\u3059\u3002<\/p>\n

 <\/p>\n

\u4e3b\u306a\u9055\u3044\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\uff1a<\/h3>\n

API\u306e\u30ec\u30d9\u30eb:<\/h4>\n

FileInputStream\/FileOutputStream\u306f\u3001\u53e4\u3044I\/O\uff08InputStream\/OutputStream\uff09API\u306b\u57fa\u3065\u3044\u3066\u304a\u308a\u3001\u30b7\u30f3\u30d7\u30eb\u306a\u30d0\u30a4\u30c8\u30b9\u30c8\u30ea\u30fc\u30e0\u306e\u8aad\u307f\u66f8\u304d\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002FileChannel\u306f\u3001\u3088\u308a\u65b0\u3057\u3044NIO\u30d1\u30c3\u30b1\u30fc\u30b8\u306b\u57fa\u3065\u3044\u3066\u304a\u308a\u3001ByteBuffer\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u306e\u8aad\u307f\u66f8\u304d\u3092\u884c\u3046\u9ad8\u5ea6\u306a\u5236\u5fa1\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002<\/p>\n

\u30c7\u30fc\u30bf\u306e\u6271\u3044\u65b9:<\/h4>\n

FileInputStream\/FileOutputStream\u306f\u30d0\u30a4\u30c8\u914d\u5217\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u3092\u8aad\u307f\u66f8\u304d\u3057\u307e\u3059\u3002FileChannel\u306fByteBuffer\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u306e\u8aad\u307f\u66f8\u304d\u3092\u884c\u3044\u307e\u3059\u3002ByteBuffer\u306f\u3001\u52b9\u7387\u7684\u306a\u30d0\u30c3\u30d5\u30a1\u30ea\u30f3\u30b0\u3084\u76f4\u63a5\u30e1\u30e2\u30ea\u30a2\u30af\u30bb\u30b9\u306a\u3069\u306e\u6a5f\u80fd\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002<\/p>\n

\u6a5f\u80fd:<\/h4>\n

FileChannel\u306f\u3001\u975e\u540c\u671fIO\u3084\u30e1\u30e2\u30ea\u30de\u30c3\u30d4\u30f3\u30b0\u30d5\u30a1\u30a4\u30eb\u306a\u3069\u306e\u9ad8\u5ea6\u306a\u6a5f\u80fd\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u4e00\u65b9\u3001FileInputStream\/FileOutputStream\u306f\u3001\u30b7\u30f3\u30d7\u30eb\u306a\u30d5\u30a1\u30a4\u30eb\u306e\u8aad\u307f\u66f8\u304d\u306b\u7279\u5316\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

 <\/p>\n

\u8981\u7d04\u3059\u308b\u3068\u3001FileInputStream\/FileOutputStream\u306f\u30b7\u30f3\u30d7\u30eb\u306a\u30d5\u30a1\u30a4\u30eb\u306e\u8aad\u307f\u66f8\u304d\u306b\u4f7f\u7528\u3055\u308c\u3001FileChannel\u306f\u3088\u308a\u9ad8\u5ea6\u306a\u5236\u5fa1\u3068\u6a5f\u80fd\u304c\u5fc5\u8981\u306a\u5834\u5408\u306b\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002\u9078\u629e\u306f\u3001\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306e\u8981\u4ef6\u3068\u30c7\u30fc\u30bf\u64cd\u4f5c\u306e\u30cb\u30fc\u30ba\u306b\u57fa\u3065\u3044\u3066\u884c\u3046\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

 <\/p>\n

\u25c7\u3044\u3056\u901f\u5ea6\u6bd4\u8f03<\/h2>\n

\u6bd4\u8f03\u30d1\u30bf\u30fc\u30f3\u306f\u4ee5\u4e0b<\/p>\n

    \n
  • \uff11\u30d5\u30a1\u30a4\u30eb\u306e\u66f8\u304d\u8fbc\u307f\u8aad\u307f\u8fbc\u307f\u901f\u5ea6\u6bd4\u8f03<\/li>\n
  • \u8907\u6570\u30d5\u30a1\u30a4\u30eb\u306e\u66f8\u304d\u8fbc\u307f\u8aad\u307f\u8fbc\u307f\u901f\u5ea6\u6bd4\u8f03<\/li>\n<\/ul>\n

     <\/p>\n

    1, \uff11\u30d5\u30a1\u30a4\u30eb\uff08200MB\uff09\u306e\u66f8\u304d\u8fbc\u307f\u3001\u8aad\u307f\u8fbc\u307f\u901f\u5ea6\u6bd4\u8f03<\/h3>\n

    File Stream (msec)<\/h4>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff11\u56de\u76ee\uff1a344<\/p>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff12\u56de\u76ee\uff1a343<\/p>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff13\u56de\u76ee\uff1a344<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff11\u56de\u76ee\uff1a219<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff12\u56de\u76ee\uff1a360<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff13\u56de\u76ee\uff1a172<\/p>\n

    FileChannel (msec)<\/h4>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff11\u56de\u76ee\uff1a281<\/p>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff12\u56de\u76ee\uff1a249<\/p>\n

    \u66f8\u304d\u8fbc\u307f\u3000\uff13\u56de\u76ee\uff1a234<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff11\u56de\u76ee\uff1a125<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff12\u56de\u76ee\uff1a125<\/p>\n

    \u8aad\u307f\u8fbc\u307f\u3000\uff13\u56de\u76ee\uff1a126<\/p>\n

     <\/p>\n

    2, \u8907\u6570\u30d5\u30a1\u30a4\u30eb\uff081000\u30d5\u30a1\u30a4\u30eb\uff09\u306e\u66f8\u304d\u8fbc\u307f\u3001\u8aad\u307f\u8fbc\u307f\u901f\u5ea6\u6bd4\u8f03<\/h3>\n

    File Stream (msec)<\/h4>\n

    \u66f8\u304d\u8fbc\u307f\uff1a3315<\/p>\n

    \u8aad\u307f\u8fbc\u307f\uff1a776<\/p>\n

    FileChannel (msec)<\/h4>\n

    \u66f8\u304d\u8fbc\u307f\uff1a3304<\/p>\n

    \u8aad\u307f\u8fbc\u307f\uff1a385<\/p>\n

     <\/p>\n

    \u25c7\u7d50\u8ad6<\/h2>\n

    FileChannel \u306f\u30b5\u30a4\u30ba\u304c\u5927\u304d\u3044\u30d5\u30a1\u30a4\u30eb\u306f\u8aad\u307f\u8fbc\u307f\u66f8\u304d\u8fbc\u307f\u3068\u3082\u306b\u901f\u3044\u3002<\/p>\n

    \u3055\u3044\u30d5\u30a1\u30a4\u30eb\u3067\u3082\u66f8\u304d\u8fbc\u307f\u306f\u5909\u308f\u3089\u306a\u3044\u304c\u8aad\u307f\u8fbc\u307f\u306f\u901f\u3044\u3002<\/p>\n

    \u3088\u3063\u3066\u30ac\u30f3\u30ac\u30f3\u4f7f\u3046\u3079\u3057\u3002<\/p>\n

    \"\"<\/p>\n

    \u25c7\u8a08\u6e2c\u306b\u4f7f\u3063\u305f\u30b3\u30fc\u30c9<\/h2>\n

    Hoge.java<\/p>\n

    import java.io.File;\r\nimport java.io.FileInputStream;\r\nimport java.io.FileOutputStream;\r\nimport java.io.IOException;\r\nimport java.nio.ByteBuffer;\r\nimport java.nio.channels.FileChannel;\r\nimport java.nio.file.Files;\r\nimport java.nio.file.Paths;\r\nimport java.nio.file.StandardOpenOption;\r\nimport java.util.Arrays;\r\n\r\npublic class Hoge {\r\n\r\n    public static void main(String[] args) throws Exception {\r\n        log(\"start ...\");\r\n        \/\/ 100MB 3\u56de\r\n        \/\/ 1KB 1000\u30d5\u30a1\u30a4\u30eb\r\n        \/\/ \u66f8\u304d\u8fbc\u307f \u8aad\u307f\u8fbc\u307f\r\n        Files.createDirectories(Paths.get(\"work\"));\r\n        testStream1();\r\n        testChannel1();\r\n        testStream2();\r\n        testChannel2();\r\n        log(\"end ...\");\r\n    }\r\n\r\n    static void testStream1() throws IOException {\r\n        log(\"---testStream1---\");\r\n        byte[] buf = new byte[200 * 1024 * 1024];\r\n        Arrays.fill(buf, (byte)35);\r\n        for (int i=0; i<3; i++) {\r\n            long t1 = System.currentTimeMillis();\r\n            File f = new File(\"work\/ts1-\" + i + \".txt\");\r\n            writeFileByStream(f, buf);\r\n            long t2 = System.currentTimeMillis();\r\n            log(\"write time: \" + (t2-t1));\r\n        }\r\n\r\n        for (int i=0; i<3; i++) {\r\n            long t1 = System.currentTimeMillis();\r\n            File f = new File(\"work\/ts1-\" + i + \".txt\");\r\n            readFileByStream(f);\r\n            long t2 = System.currentTimeMillis();\r\n            log(\"read time: \" + (t2-t1));\r\n        }\r\n    }\r\n    static void testChannel1() throws IOException {\r\n        log(\"---testChannel1---\");\r\n        byte[] buf = new byte[200 * 1024 * 1024];\r\n        Arrays.fill(buf, (byte)35);\r\n        for (int i=0; i<3; i++) {\r\n            long t1 = System.currentTimeMillis();\r\n            File f = new File(\"work\/tc1-\" + i + \".txt\");\r\n            writeFileByChannel(f, buf);\r\n            long t2 = System.currentTimeMillis();\r\n            log(\"write time:: \" + (t2-t1));\r\n        }\r\n\r\n        for (int i=0; i<3; i++) {\r\n            long t1 = System.currentTimeMillis();\r\n            File f = new File(\"work\/tc1-\" + i + \".txt\");\r\n            readFileByChannel(f);\r\n            long t2 = System.currentTimeMillis();\r\n            log(\"read time: \" + (t2-t1));\r\n        }\r\n    }\r\n\r\n    static void testStream2() throws IOException {\r\n        log(\"---testStream2---\");\r\n        byte[] buf = new byte[1 * 1024];\r\n        Arrays.fill(buf, (byte)35);\r\n        long t1 = System.currentTimeMillis();\r\n        for (int i=0; i<1000; i++) {\r\n            File f = new File(\"work\/ts2-\" + i + \".txt\");\r\n            writeFileByStream(f, buf);\r\n        }\r\n        long t2 = System.currentTimeMillis();\r\n        log(\"write time: \" + (t2-t1));\r\n\r\n        long t3 = System.currentTimeMillis();\r\n        for (int i=0; i<1000; i++) {\r\n            File f = new File(\"work\/ts2-\" + i + \".txt\");\r\n            readFileByStream(f);\r\n        }\r\n        long t4 = System.currentTimeMillis();\r\n        log(\"read time: \" + (t4-t3));\r\n    }\r\n    static void testChannel2() throws IOException {\r\n        log(\"---testChannel2---\");\r\n        byte[] buf = new byte[1 * 1024];\r\n        Arrays.fill(buf, (byte)35);\r\n        long t1 = System.currentTimeMillis();\r\n        for (int i=0; i<1000; i++) {\r\n            File f = new File(\"work\/tc2-\" + i + \".txt\");\r\n            writeFileByChannel(f, buf);\r\n        }\r\n        long t2 = System.currentTimeMillis();\r\n        log(\"write time: \" + (t2-t1));\r\n\r\n        long t3 = System.currentTimeMillis();\r\n        for (int i=0; i<1000; i++) {\r\n            File f = new File(\"work\/tc2-\" + i + \".txt\");\r\n            readFileByChannel(f);\r\n        }\r\n        long t4 = System.currentTimeMillis();\r\n        log(\"read time: \" + (t4-t3));\r\n    }\r\n\r\n\r\n    static void writeFileByStream(File f, byte[] val) throws IOException {\r\n        try (FileOutputStream out = new FileOutputStream (f, false)) {\r\n            out.write(val);\r\n        }\r\n    }\r\n    static byte[] readFileByStream(File f) throws IOException {\r\n        byte[] val = new byte[(int)f.length()];\r\n        try (FileInputStream in = new FileInputStream(f)) {\r\n            in.read(val);\r\n        }\r\n        return val;\r\n    }\r\n\r\n    static void writeFileByChannel(File f, byte[] val) throws IOException {\r\n        try (FileChannel fc = FileChannel.open(f.toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE)) {\r\n            ByteBuffer buf = ByteBuffer.wrap(val);\r\n            fc.write(buf);\r\n        }\r\n    }\r\n    static byte[] readFileByChannel(File f) throws IOException {\r\n        try (FileChannel fc = FileChannel.open(f.toPath(), StandardOpenOption.READ)) {\r\n            byte[] bytes = new byte[(int)fc.size()];\r\n            ByteBuffer buf = ByteBuffer.wrap(bytes);\r\n            fc.read(buf);\r\n            return bytes;\r\n        }\r\n    }\r\n\r\n    static void log(String msg) {\r\n        System.out.println(msg);\r\n    }<\/pre>\n
     <\/p>\n","protected":false},"excerpt":{"rendered":"
    \u3053\u3093\u306b\u3061\u308f\u3001\u732b\u597d\u304d\u30ea\u30fc\u30de\u30f3\u306e\u307b\u3052PG\u3067\u3059\u3002 \u4eca\u66f4\u306a\u304c\u3089FileChannel\u304c\u3069\u308c\u304f\u3089\u3044\u306e\u3082\u306e\u304b\u5206\u304b\u3089\u306a\u304b\u3063\u305f\u306e\u3067\u8abf\u3079\u3066\u307f\u307e\u3057\u305f\u3002 \u25c7\u305d\u308c\u305e\u308c\u306e\u7279\u5fb4 Java\u306b\u306f\u3001\u30d5\u30a1\u30a4\u30eb\u64cd\u4f5c\u306b\u4f7f\u7528\u3067\u304d\u308b\u3055\u307e\u3056\u307e\u306a\u30af\u30e9\u30b9\u3068API\u304c\u3042\u308a\u307e […]<\/p>\n","protected":false},"author":1,"featured_media":9549,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"vkexunit_cta_each_option":"","footnotes":""},"categories":[114,6],"tags":[1116,563,1115],"class_list":["post-9544","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-114","category-engineer","tag-filechannel","tag-java","tag-1115"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/posts\/9544","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/comments?post=9544"}],"version-history":[{"count":5,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/posts\/9544\/revisions"}],"predecessor-version":[{"id":9551,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/posts\/9544\/revisions\/9551"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/media\/9549"}],"wp:attachment":[{"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/media?parent=9544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/categories?post=9544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ois-yokohama.co.jp\/oisblog2018\/wp-json\/wp\/v2\/tags?post=9544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}