{"id":7222,"date":"2023-11-28T16:07:29","date_gmt":"2023-11-28T08:07:29","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=7222"},"modified":"2023-11-28T16:57:11","modified_gmt":"2023-11-28T08:57:11","slug":"java-mian-shi","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/java-mian-shi\/","title":{"rendered":"Java\u9762\u8bd5"},"content":{"rendered":"<h2><a id=\"java%E5%9F%BA%E7%A1%80\" class=\"anchor\" aria-hidden=\"true\"><\/a>Java \u57fa\u7840<\/h2>\n<h3><a id=\"jdk%E5%92%8C-jre%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>JDK \u548c JRE \u6709\u4ec0\u4e48\u533a\u522b\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">JDK\uff1aJava Development Kit \u7684\u7b80\u79f0\uff0cJava \u5f00\u53d1\u5de5\u5177\u5305\uff0c\u63d0\u4f9b\u4e86 Java \u7684\u5f00\u53d1\u73af\u5883\u548c\u8fd0\u884c\u73af\u5883\u3002\nJRE\uff1aJava Runtime Environment \u7684\u7b80\u79f0\uff0cJava \u8fd0\u884c\u73af\u5883\uff0c\u4e3a Java \u7684\u8fd0\u884c\u63d0\u4f9b\u4e86\u6240\u9700\u73af\u5883\u3002\n\u5177\u4f53\u6765\u8bf4 JDK \u5176\u5b9e\u5305\u542b\u4e86 JRE\uff0c\u540c\u65f6\u8fd8\u5305\u542b\u4e86\u7f16\u8bd1 Java \u6e90\u7801\u7684\u7f16\u8bd1\u5668 Javac\uff0c\u8fd8\u5305\u542b\u4e86\u5f88\u591a Java \u7a0b\u5e8f\u8c03\u8bd5\u548c\u5206\u6790\u7684\u5de5\u5177\u3002\u7b80\u5355\u6765\u8bf4\uff1a\u5982\u679c\u4f60\u9700\u8981\u8fd0\u884c Java \u7a0b\u5e8f\uff0c\u53ea\u9700\u5b89\u88c5 JRE \u5c31\u53ef\u4ee5\u4e86\uff0c\u5982\u679c\u4f60\u9700\u8981\u7f16\u5199 Java \u7a0b\u5e8f\uff0c\u9700\u8981\u5b89\u88c5 JDK\u3002\n<\/code><\/pre>\n<h3><a id=\"final%E5%9C%A8-java%E4%B8%AD%E6%9C%89%E4%BB%80%E4%B9%88%E4%BD%9C%E7%94%A8%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>final \u5728 Java \u4e2d\u6709\u4ec0\u4e48\u4f5c\u7528\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">final \u4fee\u9970\u7684\u7c7b\u53eb\u6700\u7ec8\u7c7b\uff0c\u8be5\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\u3002\nfinal \u4fee\u9970\u7684\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199\u3002\nfinal \u4fee\u9970\u7684\u53d8\u91cf\u53eb\u5e38\u91cf\uff0c\u5e38\u91cf\u5fc5\u987b\u521d\u59cb\u5316\uff0c\u521d\u59cb\u5316\u4e4b\u540e\u503c\u5c31\u4e0d\u80fd\u88ab\u4fee\u6539\u3002\n<\/code><\/pre>\n<h3><a id=\"java%E4%B8%AD%E7%9A%84-math-round-1-5%E7%AD%89%E4%BA%8E%E5%A4%9A%E5%B0%91%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>Java \u4e2d\u7684 Math. round(-1. 5) \u7b49\u4e8e\u591a\u5c11\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">\u7b49\u4e8e -1\uff0c\u56e0\u4e3a\u5728\u6570\u8f74\u4e0a\u53d6\u503c\u65f6\uff0c\u4e2d\u95f4\u503c\uff080.5\uff09\u5411\u53f3\u53d6\u6574\uff0c\u6240\u4ee5\u6b63 0.5 \u662f\u5f80\u4e0a\u53d6\u6574\uff0c\u8d1f 0.5 \u662f\u76f4\u63a5\u820d\u5f03\u3002\n<\/code><\/pre>\n<h3><a id=\"string%E5%B1%9E%E4%BA%8E%E5%9F%BA%E7%A1%80%E7%9A%84%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B%E5%90%97%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>String \u5c5e\u4e8e\u57fa\u7840\u7684\u6570\u636e\u7c7b\u578b\u5417\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">String \u4e0d\u5c5e\u4e8e\u57fa\u7840\u7c7b\u578b\uff0c\u57fa\u7840\u7c7b\u578b\u6709 8 \u79cd\uff1abyte\u3001boolean\u3001char\u3001short\u3001int\u3001float\u3001long\u3001double\uff0c\u800c String \u5c5e\u4e8e\u5bf9\u8c61\u3002\n<\/code><\/pre>\n<h3><a id=\"java%E4%B8%AD%E6%93%8D%E4%BD%9C%E5%AD%97%E7%AC%A6%E4%B8%B2%E9%83%BD%E6%9C%89%E5%93%AA%E4%BA%9B%E7%B1%BB%EF%BC%9F%E5%AE%83%E4%BB%AC%E4%B9%8B%E9%97%B4%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>Java \u4e2d\u64cd\u4f5c\u5b57\u7b26\u4e32\u90fd\u6709\u54ea\u4e9b\u7c7b\uff1f\u5b83\u4eec\u4e4b\u95f4\u6709\u4ec0\u4e48\u533a\u522b\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">\u64cd\u4f5c\u5b57\u7b26\u4e32\u7684\u7c7b\u6709\uff1aString\u3001StringBuffer\u3001StringBuilder\u3002\n\nString \u548c StringBuffer\u3001StringBuilder \u7684\u533a\u522b\u5728\u4e8e String \u58f0\u660e\u7684\u662f\u4e0d\u53ef\u53d8\u7684\u5bf9\u8c61\uff0c\u6bcf\u6b21\u64cd\u4f5c\u90fd\u4f1a\u751f\u6210\u65b0\u7684 String \u5bf9\u8c61\uff0c\u7136\u540e\u5c06\u6307\u9488\u6307\u5411\u65b0\u7684 String \u5bf9\u8c61\uff0c\u800c StringBuffer\u3001StringBuilder \u53ef\u4ee5\u5728\u539f\u6709\u5bf9\u8c61\u7684\u57fa\u7840\u4e0a\u8fdb\u884c\u64cd\u4f5c\uff0c\u6240\u4ee5\u5728\u7ecf\u5e38\u6539\u53d8\u5b57\u7b26\u4e32\u5185\u5bb9\u7684\u60c5\u51b5\u4e0b\u6700\u597d\u4e0d\u8981\u4f7f\u7528 String\u3002\n\nStringBuffer \u548c StringBuilder \u6700\u5927\u7684\u533a\u522b\u5728\u4e8e\uff0cStringBuffer \u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u800c StringBuilder \u662f\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u4f46 StringBuilder \u7684\u6027\u80fd\u5374\u9ad8\u4e8e StringBuffer\uff0c\u6240\u4ee5\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e0b\u63a8\u8350\u4f7f\u7528 StringBuilder\uff0c\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u63a8\u8350\u4f7f\u7528 StringBuffer\u3002\n<\/code><\/pre>\n<h3><a id=\"%E6%99%AE%E9%80%9A%E7%B1%BB%E5%92%8C%E6%8A%BD%E8%B1%A1%E7%B1%BB%E6%9C%89%E5%93%AA%E4%BA%9B%E5%8C%BA%E5%88%AB%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>\u666e\u901a\u7c7b\u548c\u62bd\u8c61\u7c7b\u6709\u54ea\u4e9b\u533a\u522b\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">\u666e\u901a\u7c7b\u4e0d\u80fd\u5305\u542b\u62bd\u8c61\u65b9\u6cd5\uff0c\u62bd\u8c61\u7c7b\u53ef\u4ee5\u5305\u542b\u62bd\u8c61\u65b9\u6cd5\u3002\n\u62bd\u8c61\u7c7b\u4e0d\u80fd\u76f4\u63a5\u5b9e\u4f8b\u5316\uff0c\u666e\u901a\u7c7b\u53ef\u4ee5\u76f4\u63a5\u5b9e\u4f8b\u5316\u3002\n<\/code><\/pre>\n<h3><a id=\"%E6%8A%BD%E8%B1%A1%E7%B1%BB%E8%83%BD%E4%BD%BF%E7%94%A8final%E4%BF%AE%E9%A5%B0%E5%90%97%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>\u62bd\u8c61\u7c7b\u80fd\u4f7f\u7528 final \u4fee\u9970\u5417\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">\u4e0d\u80fd\uff0c\u5b9a\u4e49\u62bd\u8c61\u7c7b\u5c31\u662f\u8ba9\u5176\u4ed6\u7c7b\u7ee7\u627f\u7684\uff0c\u5982\u679c\u5b9a\u4e49\u4e3a final \u8be5\u7c7b\u5c31\u4e0d\u80fd\u88ab\u7ee7\u627f\uff0c\u8fd9\u6837\u5f7c\u6b64\u5c31\u4f1a\u4ea7\u751f\u77db\u76fe\uff0c\u6240\u4ee5 final \u4e0d\u80fd\u4fee\u9970\u62bd\u8c61\u7c7b\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff0c\u7f16\u8f91\u5668\u4e5f\u4f1a\u63d0\u793a\u9519\u8bef\u4fe1\u606f\uff1a\n<\/code><\/pre>\n<h3><a id=\"%E6%8E%A5%E5%8F%A3%E5%92%8C%E6%8A%BD%E8%B1%A1%E7%B1%BB%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\" class=\"anchor\" aria-hidden=\"true\"><\/a>\u63a5\u53e3\u548c\u62bd\u8c61\u7c7b\u6709\u4ec0\u4e48\u533a\u522b\uff1f<\/h3>\n<pre><code class=\"language-plain_text\">\u5b9e\u73b0\uff1a\u62bd\u8c61\u7c7b\u7684\u5b50\u7c7b\u4f7f\u7528 extends \u6765\u7ee7\u627f\uff1b\u63a5\u53e3\u5fc5\u987b\u4f7f\u7528 implements \u6765\u5b9e\u73b0\u63a5\u53e3\u3002\n\u6784\u9020\u51fd\u6570\uff1a\u62bd\u8c61\u7c7b\u53ef\u4ee5\u6709\u6784\u9020\u51fd\u6570\uff1b\u63a5\u53e3\u4e0d\u80fd\u6709\u3002\n\u5b9e\u73b0\u6570\u91cf\uff1a\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u5f88\u591a\u4e2a\u63a5\u53e3\uff1b\u4f46\u662f\u53ea\u80fd\u7ee7\u627f\u4e00\u4e2a\u62bd\u8c61\u7c7b\u3002\n\u8bbf\u95ee\u4fee\u9970\u7b26\uff1a\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\u9ed8\u8ba4\u4f7f\u7528 public \u4fee\u9970\uff1b\u62bd\u8c61\u7c7b\u4e2d\u7684\u65b9\u6cd5\u53ef\u4ee5\u662f\u4efb\u610f\u8bbf\u95ee\u4fee\u9970\u7b26\u3002\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Java \u57fa\u7840 JDK \u548c JRE \u6709\u4ec0\u4e48\u533a\u522b\uff1f JDK\uff1aJava Development Kit \u7684\u7b80\u79f0\uff0cJ [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[99],"tags":[],"class_list":["post-7222","post","type-post","status-publish","format-standard","hentry","category-javabase"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/7222","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=7222"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/7222\/revisions"}],"predecessor-version":[{"id":7228,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/7222\/revisions\/7228"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=7222"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=7222"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=7222"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}