{"id":14044,"date":"2024-03-15T08:21:55","date_gmt":"2024-03-15T08:21:55","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-can-we-merge-streams-in-java\/"},"modified":"2025-08-06T02:56:12","modified_gmt":"2025-08-06T02:56:12","slug":"how-can-we-merge-streams-in-java","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-can-we-merge-streams-in-java\/","title":{"rendered":"Java Stream Merge: Concat Method Guide"},"content":{"rendered":"<p>In Java, you can merge streams using the concat() method from the Stream class. This method takes two streams as input and returns a new stream containing elements from both input streams.<\/p>\n<p>Here is a sample code:<\/p>\n<pre class=\"post-pre\"><code><span class=\"hljs-keyword\">import<\/span> java.util.stream.Stream;\r\n\r\n<span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title class_\">StreamMergeExample<\/span> {\r\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">static<\/span> <span class=\"hljs-keyword\">void<\/span> <span class=\"hljs-title function_\">main<\/span><span class=\"hljs-params\">(String[] args)<\/span> {\r\n        Stream&lt;String&gt; stream1 = Stream.of(<span class=\"hljs-string\">\"A\"<\/span>, <span class=\"hljs-string\">\"B\"<\/span>, <span class=\"hljs-string\">\"C\"<\/span>);\r\n        Stream&lt;String&gt; stream2 = Stream.of(<span class=\"hljs-string\">\"D\"<\/span>, <span class=\"hljs-string\">\"E\"<\/span>, <span class=\"hljs-string\">\"F\"<\/span>);\r\n\r\n        Stream&lt;String&gt; mergedStream = Stream.concat(stream1, stream2);\r\n        mergedStream.forEach(System.out::println);\r\n    }\r\n}\r\n<\/code><\/pre>\n<p>The output result is:<\/p>\n<pre class=\"post-pre\"><code>A\r\nB\r\nC\r\nD\r\nE\r\nF\r\n<\/code><\/pre>\n<p>In the example, we created two Stream objects, stream1 and stream2, which each contain strings &#8220;A&#8221;, &#8220;B&#8221;, &#8220;C&#8221; and &#8220;D&#8221;, &#8220;E&#8221;, &#8220;F&#8221; respectively. We then used the concat() method to merge the two Streams into a new Stream called mergedStream. Finally, we used the forEach() method to iterate and output the elements in the merged Stream.<\/p>\n<p>It is important to note that a Stream object can only be consumed (operated on) once. In the example, we only called the forEach() method once to output the elements in the merged Stream. If forEach() is called again, an exception will be thrown. If you need to perform multiple operations on a Stream, you can create a new Stream object to work with.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In Java, you can merge streams using the concat() method from the Stream class. This method takes two streams as input and returns a new stream containing elements from both input streams. Here is a sample code: import java.util.stream.Stream; public class StreamMergeExample { public static void main(String[] args) { Stream&lt;String&gt; stream1 = Stream.of(&#8220;A&#8221;, &#8220;B&#8221;, &#8220;C&#8221;); [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[180,11719,3738,18903,18904],"class_list":["post-14044","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-java-programming","tag-java-stream-api","tag-java-streams","tag-stream-concatenation","tag-stream-concat"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Java Stream Merge: Concat Method Guide - Blog - Silicon Cloud<\/title>\n<meta name=\"description\" content=\"Learn how to merge streams in Java using concat() method. 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