How to clean up excessive memory usage in Java?

In Java, high memory consumption is often caused by memory leaks or a large number of objects occupying memory. Below are some common methods to address high memory usage in Java:

1. Garbage Collection: The garbage collection mechanism in Java automatically collects objects that are no longer in use, freeing up memory. You can manually trigger garbage collection by calling either System.gc() or Runtime.getRuntime().gc() method.
2. Reduce object references: Make sure that objects that are no longer in use are not referenced, so that the garbage collection mechanism can reclaim them. For example, close open files or database connections in a timely manner to prevent objects from being constantly referenced.
3. Optimizing object creation and destruction: to avoid frequently creating and destroying a large number of objects, consider using techniques such as object pooling or caching to reuse objects and reduce memory usage.
4. Utilizing appropriate data structures and algorithms: Selecting the right data structure and algorithm for the scenario can prevent excessive memory consumption. For instance, using a LinkedList instead of an ArrayList to store a large number of dynamically changing objects can reduce memory usage.
5. Reduce memory usage by compressing objects, utilizing primitive data types, such as using int instead of Integer and byte[] instead of String.
6. Analyze memory leaks by using memory analysis tools like Eclipse Memory Analyzer or VisualVM to identify unused objects or objects that cannot be garbage collected, and then fix the issues in the code.
7. Increasing heap memory: If the above methods fail to effectively reduce memory usage, consider increasing the size of the Java Virtual Machine’s heap memory. You can adjust the startup parameters -Xmx and -Xms to set the maximum and initial heap memory size.

The above are some common methods to address excessive Java memory consumption, the specific approach should be chosen and adjusted based on the specific situation.