{"id":1946,"date":"2021-10-08T16:50:18","date_gmt":"2021-10-08T08:50:18","guid":{"rendered":"https:\/\/199604.com\/?p=1946"},"modified":"2021-10-08T17:06:37","modified_gmt":"2021-10-08T09:06:37","slug":"%e4%bb%8ejava-8%e5%88%b0-java-17-java-12","status":"publish","type":"post","link":"https:\/\/199604.com\/1946","title":{"rendered":"\u4eceJava 8\u5230 Java 17&#8211;Java 12"},"content":{"rendered":"<p>Java 12 \u5b83\u4e0d\u662f\u4e00\u4e2a\u957f\u4e45\u652f\u6301\uff08LTS\uff09\u7248\u672c\u3002<\/p>\n<p><strong>\u91cd\u70b9\u7279\u6027\u5217\u8868<\/strong>\uff1a<\/p>\n<ul>\n<li>Switch \u8868\u8fbe\u5f0f\uff08\u9884\u89c8\u7279\u6027\uff09<\/li>\n<li>\u6587\u4ef6\u5bf9\u6bd4\u589e\u5f3a<\/li>\n<\/ul>\n<h2>Switch \u8868\u8fbe\u5f0f\uff08\u9884\u89c8\u7279\u6027\uff09<\/h2>\n<p>\u5728 Java 12 \u4e2d\uff0c\u5bf9 <strong>Switch<\/strong> \u8868\u8fbe\u5f0f\u7684\u5199\u6cd5\u8fdb\u884c\u4e86\u6539\u8fdb\uff0c\u867d\u7136\u662f\u4e00\u4e2a\u8bed\u6cd5\u7cd6\u7684\u6539\u8fdb\uff0c\u4e5f\u8ba9 <strong>Switch<\/strong> \u7684\u4ee3\u7801\u7f16\u5199\u53d8\u5f97\u66f4\u52a0\u4f18\u96c5,\u5982\u518dJava12\u4e4b\u524d\u7684switch:<\/p>\n<pre><code class=\"language-java line-numbers\">        String day = \"march\";\n        switch (day) {\n            case \"march\":\n            case \"april\":\n            case \"may\":\n                System.out.println(\"\u6625\u5929\");\n                break;\n            case \"june\":\n            case \"july\":\n            case \"august\":\n                System.out.println(\"\u590f\u5929\");\n                break;\n            case \"september\":\n            case \"october\":\n            case \"november\":\n                System.out.println(\"\u79cb\u5929\");\n                break;\n            case \"december\":\n            case \"january\":\n            case \"february\":\n                System.out.println(\"\u51ac\u5929\");\n                break;\n        }\n<\/code><\/pre>\n<p><code>Java12or14<\/code>\u73b0\u5728\u53ef\u4ee5\u6539\u4e3a\u5982\u4e0b\u5199\u6cd5\uff1a<\/p>\n<pre><code class=\"language-java line-numbers\">        String day = \"march\";\n        switch (day) {\n            case \"march\", \"april\", \"may\" -&gt; System.out.println(\"\u6625\u5929\");\n            case \"june\", \"july\", \"august\" -&gt; System.out.println(\"\u590f\u5929\");\n            case \"september\", \"october\", \"november\" -&gt; System.out.println(\"\u79cb\u5929\");\n            case \"december\", \"january\", \"february\" -&gt; System.out.println(\"\u51ac\u5929\");\n        }\n\n<\/code><\/pre>\n<p>\u4ee5\u53ca\u5728\u8868\u8fbe\u5f0f\u8fd4\u56de\u503c,\u50cf\u4e0b\u9762\u8fd9\u6837\uff1a<\/p>\n<pre><code class=\"language-java line-numbers\">        String day = \"march\";\n        String data = switch (day) {\n            case \"march\", \"april\", \"may\" -&gt; \"\u6625\u5929\";\n            case \"june\", \"july\", \"august\" -&gt; \"\u590f\u5929\";\n            case \"september\", \"october\", \"november\" -&gt; \"\u79cb\u5929\";\n            case \"december\", \"january\", \"february\" -&gt; \"\u51ac\u5929\";\n            default -&gt; \"dayError\";\n        };\n        System.out.println(\"\u5f53\u524d\u5b63\u8282\u662f:\" + data);\n<\/code><\/pre>\n<h2>\u6587\u4ef6\u5bf9\u6bd4\u589e\u5f3a-Files.mismatch<\/h2>\n<p>\u5728 Java \u4e2d\u5bf9\u4e8e\u6587\u4ef6\u7684\u64cd\u4f5c\u5df2\u7ecf\u5728 Java 7 \u4e2d\u8fdb\u884c\u4e86\u4e00\u6b21\u589e\u5f3a\uff0c\u8fd9\u6b21 Java 12 \u53c8\u5e26\u6765\u4e86\u6587\u4ef6\u5bf9\u6bd4\u529f\u80fd\u3002\u5bf9\u6bd4\u4e24\u4e2a\u6587\u4ef6\uff0c\u5982\u679c\u5185\u5bb9\u4e00\u81f4\uff0c\u4f1a\u8fd4\u56de -1 \uff0c\u5982\u679c\u5185\u5bb9\u4e0d\u540c\uff0c\u4f1a\u8fd4\u56de\u4e0d\u540c\u7684\u5b57\u8282\u5f00\u59cb\u4f4d\u7f6e\u3002<\/p>\n<pre><code class=\"language-java line-numbers\">        \/\/ \u521b\u5efa\u4e24\u4e2a\u6587\u4ef6\n        Path pathA = Files.createFile(Paths.get(\"glj1.txt\"));\n        Path pathB = Files.createFile(Paths.get(\"glj2.txt\"));\n\n        \/\/ \u5199\u5165\u76f8\u540c\u5185\u5bb9\n        Files.write(pathA,\"abc\".getBytes(), StandardOpenOption.WRITE);\n        Files.write(pathB,\"abc\".getBytes(), StandardOpenOption.WRITE);\n        long mismatch = Files.mismatch(pathA, pathB);\n        System.out.println(mismatch);\n\n        \/\/ \u8ffd\u52a0\u4e0d\u540c\u5185\u5bb9\n        Files.write(pathA,\"123\".getBytes(), StandardOpenOption.APPEND);\n        Files.write(pathB,\"321\".getBytes(), StandardOpenOption.APPEND);\n        mismatch = Files.mismatch(pathA, pathB);\n        System.out.println(mismatch);\n\n        \/\/ \u5220\u9664\u521b\u5efa\u7684\u6587\u4ef6\n        pathA.toFile().deleteOnExit();\n        pathB.toFile().deleteOnExit();\n\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Java 12 \u5b83\u4e0d\u662f\u4e00\u4e2a\u957f\u4e45\u652f\u6301\uff08LTS\uff09\u7248\u672c\u3002 \u91cd\u70b9\u7279\u6027\u5217\u8868\uff1a Switch \u8868\u8fbe\u5f0f\uff08\u9884\u89c8\u7279\u6027\uff09 \u6587\u4ef6\u5bf9\u6bd4 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[292,130],"tags":[129],"class_list":{"0":"post-1946","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"hentry","6":"category-java","8":"tag-java"},"_links":{"self":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/comments?post=1946"}],"version-history":[{"count":2,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1946\/revisions"}],"predecessor-version":[{"id":1948,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1946\/revisions\/1948"}],"wp:attachment":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/media?parent=1946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/categories?post=1946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/tags?post=1946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}