{"id":5144,"date":"2024-03-14T02:26:34","date_gmt":"2024-03-14T02:26:34","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-to-use-java-multi-threading-locks\/"},"modified":"2025-08-01T11:18:26","modified_gmt":"2025-08-01T11:18:26","slug":"how-to-use-java-multi-threading-locks","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-to-use-java-multi-threading-locks\/","title":{"rendered":"Java Multi-threading Locks Guide"},"content":{"rendered":"<p>In Java, you can implement thread locking mechanisms using either the synchronized keyword or the ReentrantLock class.<\/p>\n<ol>\n<li>Use the synchronized keyword:<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title class_\">MyObject<\/span> {\r\n    <span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-type\">int<\/span> <span class=\"hljs-variable\">count<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-number\">0<\/span>;\r\n\r\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">synchronized<\/span> <span class=\"hljs-keyword\">void<\/span> <span class=\"hljs-title function_\">increment<\/span><span class=\"hljs-params\">()<\/span> {\r\n        count++;\r\n    }\r\n\r\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">synchronized<\/span> <span class=\"hljs-keyword\">void<\/span> <span class=\"hljs-title function_\">decrement<\/span><span class=\"hljs-params\">()<\/span> {\r\n        count--;\r\n    }\r\n}\r\n<\/code><\/pre>\n<p>In the above example, the synchronized keyword is used to decorate the increment() and decrement() methods, so that when calling these two methods, the MyObject object is locked, ensuring that only one thread can access these two methods at the same time.<\/p>\n<ol>\n<li>Utilizing the ReentrantLock class:<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-keyword\">import<\/span> java.util.concurrent.locks.Lock;\r\n<span class=\"hljs-keyword\">import<\/span> java.util.concurrent.locks.ReentrantLock;\r\n\r\n<span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title class_\">MyObject<\/span> {\r\n    <span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-type\">int<\/span> <span class=\"hljs-variable\">count<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-number\">0<\/span>;\r\n    <span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-type\">Lock<\/span> <span class=\"hljs-variable\">lock<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">ReentrantLock<\/span>();\r\n\r\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">void<\/span> <span class=\"hljs-title function_\">increment<\/span><span class=\"hljs-params\">()<\/span> {\r\n        lock.lock();\r\n        <span class=\"hljs-keyword\">try<\/span> {\r\n            count++;\r\n        } <span class=\"hljs-keyword\">finally<\/span> {\r\n            lock.unlock();\r\n        }\r\n    }\r\n\r\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">void<\/span> <span class=\"hljs-title function_\">decrement<\/span><span class=\"hljs-params\">()<\/span> {\r\n        lock.lock();\r\n        <span class=\"hljs-keyword\">try<\/span> {\r\n            count--;\r\n        } <span class=\"hljs-keyword\">finally<\/span> {\r\n            lock.unlock();\r\n        }\r\n    }\r\n}\r\n<\/code><\/pre>\n<p>In the example above, a lock object named &#8216;lock&#8217; is created using the ReentrantLock class. The lock() method is used to lock the object in the increment() and decrement() methods, while the unlock() method is used to release the lock. This allows for more flexible control over lock acquisition and release.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In Java, you can implement thread locking mechanisms using either the synchronized keyword or the ReentrantLock class. Use the synchronized keyword: public class MyObject { private int count = 0; public synchronized void increment() { count++; } public synchronized void decrement() { count&#8211;; } } In the above example, the synchronized keyword is used to [&hellip;]<\/p>\n","protected":false},"author":8,"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":[219,5350,2583,5446,396],"class_list":["post-5144","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-java-concurrency","tag-java-locks","tag-reentrantlock","tag-synchronized-keyword","tag-thread-safety"],"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 Multi-threading Locks Guide - Blog - 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