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docs: update docs/java.md. (#601) 1b9437656d
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jaywcjlove
@ -158,7 +158,7 @@
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</span><span class="code-line"><span class="token comment">// byte<short<int<long<float<double</span>
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</span><span class="code-line"><span class="token keyword">int</span> i <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token keyword">long</span> l <span class="token operator">=</span> i<span class="token punctuation">;</span> <span class="token comment">// 10</span>
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</span><span class="code-line"><span class="token comment">// Narrowing </span>
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</span><span class="code-line"><span class="token comment">// Narrowing</span>
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</span><span class="code-line"><span class="token keyword">double</span> d <span class="token operator">=</span> <span class="token number">10.02</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token keyword">long</span> l <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token keyword">long</span><span class="token punctuation">)</span>d<span class="token punctuation">;</span> <span class="token comment">// 10</span>
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</span><span class="code-line"><span class="token class-name">String</span><span class="token punctuation">.</span><span class="token function">valueOf</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// "10"</span>
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@ -316,7 +316,7 @@
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</span><span class="code-line"><span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">int</span> a<span class="token operator">:</span> arr<span class="token punctuation">)</span> <span class="token punctuation">{</span>
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</span><span class="code-line"> <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">" "</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token punctuation">}</span>
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</span><span class="code-line"><span class="token comment">// 输出: a b c </span>
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</span><span class="code-line"><span class="token comment">// 输出: a b c</span>
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</span></code></pre>
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</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="二维数组-multidimensional-arrays"><a aria-hidden="true" tabindex="-1" href="#二维数组-multidimensional-arrays"><span class="icon icon-link"></span></a>二维数组 Multidimensional Arrays</h3><div class="wrap-body">
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<pre class="language-java"><code class="language-java code-highlight"><span class="code-line"><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">[</span><span class="token punctuation">]</span> matrix <span class="token operator">=</span> <span class="token punctuation">{</span> <span class="token punctuation">{</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token punctuation">{</span><span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">;</span>
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@ -328,7 +328,7 @@
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</span><span class="code-line"> <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>a<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">[</span>j<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"> <span class="token punctuation">}</span>
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</span><span class="code-line"><span class="token punctuation">}</span>
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</span><span class="code-line"><span class="token comment">// 输出: 1 2 3 4 5 6 7 </span>
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</span><span class="code-line"><span class="token comment">// 输出: 1 2 3 4 5 6 7</span>
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</span></code></pre>
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</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="排序-sort"><a aria-hidden="true" tabindex="-1" href="#排序-sort"><span class="icon icon-link"></span></a>排序 Sort</h3><div class="wrap-body">
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<pre class="language-java"><code class="language-java code-highlight"><span class="code-line"><span class="token keyword">char</span><span class="token punctuation">[</span><span class="token punctuation">]</span> chars <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token char">'b'</span><span class="token punctuation">,</span> <span class="token char">'a'</span><span class="token punctuation">,</span> <span class="token char">'c'</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
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@ -1174,6 +1174,37 @@
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</span><span class="code-line"><span class="token comment">// 2: 3</span>
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</span><span class="code-line"><span class="token comment">// 3: 1</span>
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</span></code></pre>
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<p><code>Stream</code>是<code>JAVA 8</code>添加的新特性，类似于一种管道。</p>
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<pre class="language-java"><code class="language-java code-highlight"><span class="code-line"><span class="token comment">// Create the stream</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">></span></span> test <span class="token operator">=</span> <span class="token class-name">Arrays</span><span class="token punctuation">.</span><span class="token function">asList</span><span class="token punctuation">(</span><span class="token string">"123"</span><span class="token punctuation">,</span> <span class="token string">"456"</span><span class="token punctuation">,</span> <span class="token string">"789"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token class-name">Stream</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">></span></span> stram <span class="token operator">=</span> test<span class="token punctuation">.</span><span class="token function">stream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token comment">// some intermediate operations</span>
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</span><span class="code-line">
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</span><span class="code-line"><span class="token comment">// fillter</span>
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</span><span class="code-line"><span class="token comment">// The original operation</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">TestDO</span><span class="token punctuation">></span></span> resultList <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token generics"><span class="token punctuation"><</span><span class="token punctuation">></span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"><span class="token keyword">for</span><span class="token punctuation">(</span><span class="token class-name">TestDO</span> test<span class="token operator">:</span> testList<span class="token punctuation">)</span><span class="token punctuation">{</span>
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</span><span class="code-line"> <span class="token keyword">if</span><span class="token punctuation">(</span>test<span class="token punctuation">.</span><span class="token function">getTest</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span><span class="token class-name">Boolean</span><span class="token punctuation">.</span><span class="token constant">TRUE</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
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</span><span class="code-line"> resultList<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>test<span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line"> <span class="token punctuation">}</span>
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</span><span class="code-line"><span class="token punctuation">}</span>
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</span><span class="code-line"><span class="token comment">// The stream operation</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">TestDO</span><span class="token punctuation">></span></span> resultList <span class="token operator">=</span> testList<span class="token punctuation">.</span><span class="token function">stream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">fillter</span><span class="token punctuation">(</span>test <span class="token operator">-></span> test<span class="token punctuation">.</span><span class="token function">getTest</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span><span class="token class-name">Boolean</span><span class="token punctuation">.</span><span class="token constant">TRUE</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">collect</span><span class="token punctuation">(</span><span class="token class-name">Collectors</span><span class="token punctuation">.</span><span class="token function">toList</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">
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</span><span class="code-line"><span class="token comment">//distinct</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">></span></span> test <span class="token operator">=</span> <span class="token class-name">Arrays</span><span class="token punctuation">.</span><span class="token function">asList</span><span class="token punctuation">(</span><span class="token string">"123"</span><span class="token punctuation">,</span> <span class="token string">"456"</span><span class="token punctuation">,</span> <span class="token string">"789"</span><span class="token punctuation">,</span> <span class="token string">"123"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">test<span class="token punctuation">.</span><span class="token function">stream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">distinct</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">
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</span><span class="code-line"><span class="token comment">//map</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">String</span><span class="token punctuation">></span></span> test <span class="token operator">=</span> <span class="token class-name">Arrays</span><span class="token punctuation">.</span><span class="token function">asList</span><span class="token punctuation">(</span><span class="token string">"123"</span><span class="token punctuation">,</span> <span class="token string">"456"</span><span class="token punctuation">,</span> <span class="token string">"789"</span><span class="token punctuation">,</span> <span class="token string">"123"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">test<span class="token punctuation">.</span><span class="token function">stream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">map</span><span class="token punctuation">(</span>i <span class="token operator">-></span> i <span class="token operator">+</span> <span class="token string">"hh"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">
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</span><span class="code-line"><span class="token comment">// sorted</span>
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</span><span class="code-line"><span class="token class-name">List</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">Integer</span><span class="token punctuation">></span></span> numbers <span class="token operator">=</span> <span class="token class-name">Arrays</span><span class="token punctuation">.</span><span class="token function">asList</span><span class="token punctuation">(</span><span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">numbers<span class="token punctuation">.</span><span class="token function">stream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">sorted</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
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</span><span class="code-line">
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</span><span class="code-line">
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</span></code></pre>
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</div></div></div></div></div><div class="wrap h2body-not-exist"><div class="wrap-header h2wrap"><h2 id="另见"><a aria-hidden="true" tabindex="-1" href="#另见"><span class="icon icon-link"></span></a>另见</h2><div class="wrap-body">
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<ul>
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<li><a href="https://www.oracle.com/cn/java/">Java 官网</a> <em>(oracle.com/cn/java)</em></li>
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@ -1334,7 +1334,7 @@
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<!--rehype:class=home-card home-links-->
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<p>如果你有资源，可以很方便<a href="https://github.com/jaywcjlove/reference/issues/102#issue-1451649637">部署 web 版</a>，这非常简单，只需要克隆 <a href="https://github.com/jaywcjlove/reference/tree/gh-pages">gh-pages</a> 分支代码到你的静态服务就可以了，还可以使用 <a href="https://hub.docker.com/r/wcjiang/reference">docker</a> 快捷部署 web 版。</p>
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</div></div><div class="h2wrap-body"></div></div></div></div><footer class="footer-wrap"><footer class="max-container">© 2022 <a href="https://wangchujiang.com/#/app" target="_blank">Kenny Wang</a>. Updated on 2024/04/08 02:40:30</footer></footer><script src="data.js?v=1.5.3" defer></script><script src="js/fuse.min.js?v=1.5.3" defer></script><script src="js/main.js?v=1.5.3" defer></script><div id="mysearch"><div class="mysearch-box"><div class="mysearch-input"><div><svg xmlns="http://www.w3.org/2000/svg" height="1em" width="1em" viewBox="0 0 18 18">
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</div></div><div class="h2wrap-body"></div></div></div></div><footer class="footer-wrap"><footer class="max-container">© 2022 <a href="https://wangchujiang.com/#/app" target="_blank">Kenny Wang</a>. Updated on 2024/04/09 11:45:10</footer></footer><script src="data.js?v=1.5.3" defer></script><script src="js/fuse.min.js?v=1.5.3" defer></script><script src="js/main.js?v=1.5.3" defer></script><div id="mysearch"><div class="mysearch-box"><div class="mysearch-input"><div><svg xmlns="http://www.w3.org/2000/svg" height="1em" width="1em" viewBox="0 0 18 18">
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