{"id":1949,"date":"2021-10-08T17:15:15","date_gmt":"2021-10-08T09:15:15","guid":{"rendered":"https:\/\/199604.com\/?p=1949"},"modified":"2021-10-08T17:15:15","modified_gmt":"2021-10-08T09:15:15","slug":"%e4%bb%8ejava-8%e5%88%b0-java-17-java-13","status":"publish","type":"post","link":"https:\/\/199604.com\/1949","title":{"rendered":"\u4eceJava 8\u5230 Java 17&#8211;Java 13"},"content":{"rendered":"<p>Java 13 \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>\u52a8\u6001\u5e94\u7528\u7a0b\u5e8f\u7c7b-\u6570\u636e\u5171\u4eab<\/li>\n<li>\u589e\u5f3a ZGC \u91ca\u653e\u672a\u4f7f\u7528\u5185\u5b58<\/li>\n<li>Socket API \u91cd\u6784<\/li>\n<li>Switch \u8868\u8fbe\u5f0f\u6269\u5c55\uff08\u9884\u89c8\u529f\u80fd\uff09<\/li>\n<li>\u6587\u672c\u5757\uff08\u9884\u89c8\u529f\u80fd\uff09<\/li>\n<\/ul>\n<h2>\u52a8\u6001\u5e94\u7528\u7a0b\u5e8f\u7c7b-\u6570\u636e\u5171\u4eab<\/h2>\n<p>JDK5\u5f15\u5165\u4e86Class-Data Sharing\u53ef\u4ee5\u7528\u4e8e\u591a\u4e2aJVM\u5171\u4eabclass\uff0c\u63d0\u5347\u542f\u52a8\u901f\u5ea6\uff0c\u6700\u65e9\u53ea\u652f\u6301system classes\u53caserial GC<\/p>\n<p>JDK9\u5bf9\u5176\u8fdb\u884c\u6269\u5c55\u4ee5\u652f\u6301application classes\u53ca\u5176\u4ed6GC\u7b97\u6cd5<\/p>\n<p>java10\u7684\u65b0\u7279\u6027JEP 310: Application Class-Data Sharing\u6269\u5c55\u4e86JDK5\u5f15\u5165\u7684Class-Data Sharing\uff0c\u652f\u6301application\u7684Class-Data Sharing\u5e76\u5f00\u6e90\u51fa\u6765(\u4ee5\u524d\u662fcommercial feature)<\/p>\n<p>JDK11\u5c06-Xshare:off\u6539\u4e3a\u9ed8\u8ba4-Xshare:auto\uff0c\u4ee5\u66f4\u52a0\u65b9\u4fbf\u4f7f\u7528CDS\u7279\u6027<\/p>\n<p>JDK12\u7684341: Default CDS Archives\u5373\u572864-bit\u5e73\u53f0\u4e0a\u7f16\u8bd1jdk\u7684\u65f6\u5019\u5c31\u9ed8\u8ba4\u5728&dollar;{JAVA_HOME}\/lib\/server\u76ee\u5f55\u4e0b\u751f\u6210\u4e00\u4efd\u540d\u4e3aclasses.jsa\u7684\u9ed8\u8ba4archive\u6587\u4ef6(\u5927\u6982\u670918M)\u65b9\u4fbf\u5927\u5bb6\u4f7f\u7528<\/p>\n<p>JDK13\u7684\u8fd9\u4e2a\u7279\u6027\u652f\u6301\u5728Java application\u6267\u884c\u4e4b\u540e\u8fdb\u884c\u52a8\u6001archive<\/p>\n<h3>\u5bfc\u51fajsa\uff1a<\/h3>\n<p><code>java -XX:ArchiveClassesAtExit=hello.jsa -cp hello.jar Hello<\/code><\/p>\n<h3>\u4f7f\u7528jsa:<\/h3>\n<p><code>java -XX:SharedArchiveFile=hello.jsa -cp hello.jar Hello<\/code><\/p>\n<h2>\u589e\u5f3a ZGC \u91ca\u653e\u672a\u4f7f\u7528\u5185\u5b58<\/h2>\n<p>\u6682\u65f6\u65e0..<\/p>\n<h2>Switch \u8868\u8fbe\u5f0f\u6269\u5c55\uff08\u9884\u89c8\u529f\u80fd\uff09<\/h2>\n<p>\u5728 Java 12 \u4e2d\u5f15\u5165\u4e86 <code>Switch<\/code> \u8868\u8fbe\u5f0f\u4f5c\u4e3a\u9884\u89c8\u7279\u6027\uff0c\u800c\u5728 Java 13 \u4e2d\u5bf9 <code>Switch<\/code> \u8868\u8fbe\u5f0f\u505a\u4e86\u589e\u5f3a\u6539\u8fdb\uff0c\u5728\u5757\u4e2d\u5f15\u5165\u4e86 <code>yield<\/code> \u8bed\u53e5\u6765\u8fd4\u56de\u503c\uff0c\u800c\u4e0d\u662f\u4f7f\u7528 <code>break<\/code>\u3002\u8fd9\u610f\u5473\u7740\uff0c<code>Switch<\/code> \u8868\u8fbe\u5f0f\uff08\u8fd4\u56de\u503c\uff09\u5e94\u8be5\u4f7f\u7528 <code>yield<\/code>\uff0c\u800c <code>Switch<\/code> \u8bed\u53e5\uff08\u4e0d\u8fd4\u56de\u503c\uff09\u5e94\u8be5\u4f7f\u7528 <code>break<\/code>\uff0c\u800c\u5728\u6b64\u4e4b\u524d\uff0c\u60f3\u8981\u5728 <code>Switch<\/code> \u4e2d\u8fd4\u56de\u5185\u5bb9\uff0c\u8fd8\u662f\u6bd4\u8f83\u9ebb\u70e6\u7684\uff0c\u53ea\u4e0d\u8fc7\u76ee\u524d\u8fd8\u5904\u4e8e\u9884\u89c8\u72b6\u6001\u3002<\/p>\n<p>\u5728 Java 13 \u4e4b\u540e\uff0c<code>Switch<\/code> \u8868\u8fbe\u5f0f\u4e2d\u5c31\u591a\u4e86\u4e00\u4e2a\u5173\u952e\u5b57\u7528\u4e8e\u8df3\u51fa <code>Switch<\/code> \u5757\u7684\u5173\u952e\u5b57 <code>yield<\/code>\uff0c\u4e3b\u8981\u7528\u4e8e\u8fd4\u56de\u4e00\u4e2a\u503c\uff0c\u5b83\u548c <code>return<\/code> \u7684\u533a\u522b\u5728\u4e8e\uff1a<code>return<\/code> \u4f1a\u76f4\u63a5\u8df3\u51fa\u5f53\u524d\u5faa\u73af\u6216\u8005\u65b9\u6cd5\uff0c\u800c <code>yield<\/code> \u53ea\u4f1a\u8df3\u51fa\u5f53\u524d <code>Switch<\/code> \u5757\uff0c\u540c\u65f6\u5728\u4f7f\u7528 <code>yield<\/code> \u65f6\uff0c\u9700\u8981\u6709 <code>default<\/code> \u6761\u4ef6\u3002<\/p>\n<p>\u5728 Java 12 \u4e4b\u524d\uff0c\u4f20\u7edf <code>Switch<\/code> \u8bed\u53e5\u5199\u6cd5\u4e3a\uff1a<\/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>\u5728 Java 12 \u4e4b\u540e\uff0c\u5173\u4e8e Switch \u8868\u8fbe\u5f0f\u7684\u5199\u6cd5\u6539\u8fdb\u4e3a\u5982\u4e0b\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<p>\u800c\u5728 Java 13 \u4e2d\uff0c<code>value break<\/code> \u8bed\u53e5\u4e0d\u518d\u88ab\u7f16\u8bd1\uff0c\u800c\u662f\u7528 <code>yield<\/code> \u6765\u8fdb\u884c\u503c\u8fd4\u56de\uff0c\u4e0a\u8ff0\u5199\u6cd5\u88ab\u6539\u4e3a\u5982\u4e0b\u5199\u6cd5\uff1a<\/p>\n<pre><code class=\"language-java line-numbers\">        String day = \"march\";\n        String data = switch (day) {\n            case \"march\", \"april\", \"may\":\n                yield \"\u6625\u5929\";\n            case \"june\", \"july\", \"august\":\n                yield \"\u590f\u5929\";\n            case \"september\", \"october\", \"november\":\n                yield \"\u79cb\u5929\";\n            case \"december\", \"january\", \"february\":\n                yield \"\u51ac\u5929\";\n            default:\n                yield \"unknown\";\n        };\n        System.out.println(\"\u5f53\u524d\u5b63\u8282\u662f:\" + data);\n<\/code><\/pre>\n<h2>\u6587\u672c\u5757\uff08\u9884\u89c8\u529f\u80fd\uff09<\/h2>\n<p>\u5728 Java 13 \u4e4b\u524d\uff0c\u591a\u884c\u5b57\u7b26\u4e32\u5199\u6cd5\u4e3a\uff1a<\/p>\n<pre><code class=\"language-java line-numbers\">String html =\"&lt;html&gt;\\n\" +\n              \"   &lt;body&gt;\\n\" +\n              \"      &lt;p&gt;Hello, World&lt;\/p&gt;\\n\" +\n              \"   &lt;\/body&gt;\\n\" +\n              \"&lt;\/html&gt;\\n\";\n\n\n String json =\"{\\n\" +\n              \"   \\\"name\\\":\\\"glj\\\",\\n\" +\n              \"   \\\"age\\\":25\\n\" +\n              \"}\\n\";\n<\/code><\/pre>\n<p>\u5728 Java 13 \u5f15\u5165\u6587\u672c\u5757\u4e4b\u540e\uff0c\u5199\u6cd5\u4e3a\uff1a<\/p>\n<pre><code class=\"language-java line-numbers\">        String html = \"\"\"\n                &lt;html&gt;\n                    &lt;body&gt;\n                        &lt;p&gt;Hello, World&lt;\/p&gt;\n                    &lt;\/body&gt;\n                &lt;\/html&gt;\n                \"\"\";\n\n        String json = \"\"\"\n                {\n                    \"name\":\"glj\",\n                    \"age\":25\n                }\n                \"\"\";\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Java 13 \u5b83\u4e0d\u662f\u4e00\u4e2a\u957f\u4e45\u652f\u6301\uff08LTS\uff09\u7248\u672c\u3002 \u91cd\u70b9\u7279\u6027\u5217\u8868\uff1a \u52a8\u6001\u5e94\u7528\u7a0b\u5e8f\u7c7b-\u6570\u636e\u5171\u4eab \u589e\u5f3a ZGC \u91ca [&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-1949","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\/1949","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=1949"}],"version-history":[{"count":1,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1949\/revisions"}],"predecessor-version":[{"id":1950,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1949\/revisions\/1950"}],"wp:attachment":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/media?parent=1949"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/categories?post=1949"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/tags?post=1949"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}