how to monitor java memory usage

The new Android 1.5 early look SDK is out since a few weeks. the "android 1.5 highlights" page does not mention one highlight, which IMHO will become very important for all developers on the Android platform because it allows you to find memory leaks easily and analyze the memory usage of your android applications. I'm talking aboutHprof-Conv ToolThat allows you

As we all knowProgramOOM is easy to appear, and most of the time is triggered by bitmap Decode: Error/androidruntime (16350): Java. Lang. outofmemoryerror: bitmap size exceeds VM budget We know that the memory of the android program is generally limited to 16 MB, of course there are also 24 MB, and the memory of the android program is divided into two parts:

To understand the Java garbage collection mechanism, it is important to understand the JVM memory pattern first. Today we will understand the various parts of the JVM's memory, how to monitor it, and the garbage collection tuning.Java (JVM) memory modelAs you can see from the above picture, the JVM

the heap sizeModify Tomcat_home/bin/catalina.batAdd the following line to the "echo" Using catalina_base: $CATALINA _base "":Java_opts= "-server-xms800m-xmx800m-xx:maxnewsize=256m"Iv. use of performance check toolsTo locate a memory leak:The Jprofiler tool is primarily used to examine and track the performance of the system (limited to Java development). Jprofiler can monitor the operation of the JVM and i

Usage of the arraylist class in Java) 1. What is arraylist?Arraylist is the legendary dynamic array. In msdn, It is the complex version of array. It provides the following benefits:Dynamically add and remove elementsIcollection and ilist interfaces are implemented.Flexible array size setting 2. How to Use arraylistThe simplest example:Arraylist list = new arraylist ();For (INT I = 0; I List. Add (I );//...

the data types occupy only one. The memory space required for a local variable table is allocated during compilation, and when entering a method, this method needs to allocate a large amount of local variable space in the frame, which is completely determined and does not change the size of the local variable table during the run of the method.There are two exceptions in this region: if the thread's request has a stack depth greater than the virtual

First, what is the Java memory modelThe Java Virtual Machine specification attempts to define a Java memory model (MODEL,JMM) that masks the access differences of various hardware and operating systems to allow Java programs to ac

First, what is Leakcanary?Leakcanary is a tool used to detect memory leaks on the Android side. Ability to detect leaks in activityWhat is a memory leak?Java objects are sometimes "long dead", the GC has no way, this is a memory leak. The reason for this is that Java objects

thrown. Local Method Stack Java Virtual machine stacks are used to perform Java method services for virtual machines. While the local method stack performs the native method service for the virtual machine, the other basic and Java Virtual machine stacks are similar, the language of the local method stack, the usage a

we have several functions that can access GC, such as the system. GC () function that runs GC, according to the Java language specification definition, this function does not guarantee that the JVM garbage collector will certainly execute. Because different JVM implementers may use different algorithms to manage GC. Generally, the priority of GC threads is low. There are also many policies for JVM to call GC. Some of them start to work when the

implementation has been implemented.In the development of multithreaded code, we can directly use synchronized and other keywords to control concurrency, never need to care about the underlying compiler optimization, cache consistency and other issues. Therefore, the Java memory model, in addition to defining a set of specifications, also provides a series of primitives, encapsulated the underlying impleme

Objective Make a small summary of the JVM learning process by learning more about the Java Virtual machine tutorials, as well as your own online query information. This article begins with a description of the memory distribution area of Java, followed by memory allocation principles and

reclaimed by the garbage collector. In the case of insufficient memory space, the Java virtual machine prefers to throw outofmemory errors, cause the program to terminate abnormally, and not strongly reference objects to resolve out-of-memory issues. Soft references (SoftReference) If the memory spa

"" Generate "Kvill" exist in memory, and then "Kvill ans" is generated, and the address of this string is assigned to STR, It is because string "immutable" produces a lot of temporary variables, which is why it is suggested that StringBuffer be used because StringBuffer is changeable. Final usage and understanding in string Java code Final StringBuffer