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| Java Testing Q&A » performance » performance 1 |
1. Java: Advice on handling large data volumes. (Part Deux) stackoverflow.comAlright. So I have a very large amount of binary data (let's say, 10GB) distributed over a bunch of files (let's say, 5000) of varying lengths. I am writing a Java ... | ||
2. Calculate Throughput stackoverflow.comI have a the following scenarios. I am trying to calculate throughput of the java's XSLT transformer. I have 10 threrads, each iterates 1000 times. The task of the thread is ... | ||
3. .toArray(new MyClass[0]) or .toArray(new MyClass[myList.size()])? stackoverflow.comAssuming I have an ArrayList | ||
4. Java2D Performance Issues stackoverflow.comI'm having performance oddities with Java2D. I know of the sun.java2d.opengl VM parameter to enable 3D acceleration for 2D, but even using that has some weird issues. Here are results of ... | ||
5. Castor performance issues stackoverflow.comWe recently upgraded to Castor 1.2 from version 0.9.5.3 and we've noticed a dramatic drop in performance when calling unmarshal on XML. We're unmarshaling to java classes that were generated ... | ||
6. Lookup Op performance stackoverflow.comI'm trying to squeeze some more performance out of my rendering pipeline. The (by far) slowest part is performing a java.awt.imaging.LookupOp on a large image. The image size is ... | ||
7. Is there any performance reason to declare method parameters final in Java? stackoverflow.comIs there any performance reason to declare method parameters final in Java? As in: bar is only read ... | ||
8. Java performance with very large amounts of RAM stackoverflow.comI'm exploring the possibility of running a Java app on a machine with very large amounts of RAM (anywhere from 300GB to 15TB, probably on an SGI Altix 4700 machine), and ... | ||
9. System.currentTimeMillis() vs. new Date() vs. Calendar.getInstance().getTime() stackoverflow.comIn Java, what are the performance and resource implications of using | ||
10. Java for Audio Processing is it Practical? stackoverflow.comIs Java a suitable alternative to C / C++ for realtime audio processing? I am considering an app with ~100 (at max) tracks of audio with delay lines (30s @ 48khz), filtering ... | ||
11. int or Integer stackoverflow.comI need to create a data transfer object, which I will use for storing the records retrieved from database. In this data transfer object, I need to declare a numeric field. ... | ||
12. Java Performance Testing stackoverflow.comI want to do some timing tests on a Java application. This is what I am currently doing: | ||
13. JAVA- Function to determine whether a poker hand is a straight? stackoverflow.comfor a homework assignment I was given a Card class that has enumerated types for the Rank and Suit. I am required to compare two pokerhands (each hand is an ArrayList ... | ||
14. How to remove System.out.println's from codebase stackoverflow.comWe have a huge (old legacy java) code-base, where many files (around 5k) have System.out.println's. We are planning to remove them for cleanup/performance reasons. How can we write a script that ... | ||
15. Has anyone found Garbage Collection tuning to be useful? stackoverflow.comI've read plenty of articles about tuning GC in Java and have often wondered how many people really use some of the more advanced features. I've always avoided tuning where possible and ... | ||
16. Java switch cases: with or without braces? stackoverflow.comConsider the following two snippets, with braces: | ||
17. Does XtUnit support performance testing? stackoverflow.comDoes XtUnit support performance testing? | ||
18. Horrendous Performance in a Simple Java2D App stackoverflow.comI've just finished my entry for the 14th Ludum Dare 48-hours game making competition yesterday, and decided to do it in java using java2d for the graphics. I'm not ... | ||
19. Vast difference in Java Performance from 1.4 to 1.6 stackoverflow.comI have observed a great difference in Sun Java performance when code is compiled through jdk1.6 as compared to jdk1.5 or jdk1.4 (over 4 folds) What changes and optimizations have been done? ... | ||
20. Can I compile java myself? stackoverflow.comIs they say that sun's java is opensource now - then can I compile all the patform from sources ? I used gentoo and I found a great performance inmrovement wnen I ... | ||
21. Using hprof on a running application in Sun Java 5 stackoverflow.comWe have an enterprise java application(ear - few ejb's and a webapp) deployed on to weblogic 10 and using Sun java 5. The response time , CPU and memory usage is ... | ||
22. Java Realtime Performance stackoverflow.comI'm working with Java project that requires very advanced manipulations of images. In fact, I'm doing most of the manipulation using OpenCV, and I'm using JNI to wrap around the OpenCV ... | ||
23. Efficiency of Java "Double Brace Initialization"? stackoverflow.comIn Hidden Features of Java the top answer mentions Double Brace Initialization, with a very enticing syntax: | ||
24. Java: What's the reason behind System.out.println() being that slow? stackoverflow.comFor small logical programs that can be done in a text editor, for tracing I use the classic | ||
25. When to Be Specific About the Type of List You Want stackoverflow.comLet's say I have a class which, internally, stores a List of data: | ||
26. Does Java optimize method calls via an interface which has a single implementor marked as final? stackoverflow.comIf I have a reference to a class and invoke a method on it, and the class or the method is final, my understanding is that the compiler or the JVM ... | ||
27. Fastest way to iterate in Java stackoverflow.comIn Java, is it faster to iterate through an array the old-fashioned way, | ||
28. White papers and books on programming for performance in Java stackoverflow.comI'm looking for a white paper or online book/tutorial about coding efficiently in Java. I've read the white paper from Sun on Performance Tuning (which was mostly about JVM settings) and ... | ||
29. Is there a performance difference between these two pieces of code? stackoverflow.comIs there a performance difference between these two pieces of code? My gut feeling is that the second option is slower, as the Cell object has to be constructed each ... | ||
30. Java performance Inconsistent stackoverflow.comI have an interpreter written in Java. I am trying to test the performance results of various optimisations in the interpreter. To do this I parse the code and then repeatedly ... | ||
31. Speed tradeoff of Java's -Xms and -Xmx options stackoverflow.comGiven these two commands A:
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32. What should I look for when improving performance in Java? stackoverflow.comI work in the maintenance team of a big project (around 7k+ classes) and my daily work is mainly to fix bugs. Sometimes, though, I have no bugs to work in. ... | ||
33. Java performance timing library stackoverflow.comI frequent wrap code in a System.nanoTime() pair in order to timing it. Something like: | ||
34. Which constructor is better for StreamResult()? stackoverflow.comIt's my first time posing a question here. I would like to know which constructor is better in terms of performance for a large xml dom to be written to a ... | ||
35. Does java garbage scheduler depict it details in some form? stackoverflow.comThe scheduler that runs as a daemon in JVM to garbage collect objects, can it be monitored with JMX.Do we have some way of telling that these are the objects it ... | ||
36. How using BigDecimal would affect application performance? stackoverflow.comI want to use BigDecimal to represent arbitrary precision numbers like prices and amounts in a low-latency trading application with thousands of orders and execution reports per second. I won't be ... | ||
37. Antivirus (Symantec Endpoint) configuration for developer machine stackoverflow.comWhat are your "Symantec Endpoint" configuration recommendations for a developer PC? We do java development with Eclipse, IntelliJ, Ant and Tomcat. With "Symantec Endpoint" the build and server startup are quite ... | ||
38. Most frequently repeated numbers in a huge list of numbers stackoverflow.comI have a file which has a many random integers(around a million) each seperated by a white space. I need to find the top 10 most frequently occurring numbers in that ... | ||
39. Technique or utility to minimize Java "warm-up" time? stackoverflow.comI am supporting a Java messaging application that requires low latency (< 300 microseconds processing each message). However, our profiling shows that the Sun Java Virtual Machine runs slowly at first, ... | ||
40. What are the main Skills to be a Performance Consultant? stackoverflow.comIf I want to become a Performance Consultant for Java applications and systems, what are the main skills I need?
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41. Why is my java application faster on an AMD processor? stackoverflow.comI made the observation that my java application is running much faster when executed on an AMD processor in contrast to an Intel CPU. For example my JBoss starts in about 30 ... | ||
42. Performance of java on different hardware? stackoverflow.comIn another SO question I asked why my java programs run faster on AMD than on Intel machines. But it seems that I'm the only one who has observed this. Now ... | ||
43. Which of these pieces of code is faster in Java? stackoverflow.coma) | ||
44. Java - how to determine the current load stackoverflow.comHow would I determine the current server load? Do I need to use JMX here to get the cpu time, or is there another way to determine that or something ... | ||
45. Java ResourceBundle Performance stackoverflow.comI am using a ResourceBundle and Locale to lookup property values. Quite simply, the code looks like this: | ||
46. Sampling in visual vm stackoverflow.comCan anyone explain the science behind the sampling functionality of visualvm ? I would have thought that collecting the amount of CPU spent on each particular method would require instrumenting ... | ||
47. what is the use of Long.reverse(long ) method? stackoverflow.comI found one method in Long class
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48. Performance penalty of getSerializedSize() in Protocol Buffers stackoverflow.comIs there a performance penalty for calling | ||
49. What does "garbage collection rate" mean, and what benefit it could provide? stackoverflow.comIn analyzing Java GC behavior, some tools has the metric "garbage collection rate" (an example would be in figure 19. from http://www.ibm.com/developerworks/java/library/j-ibmtools2/#fig19) of which the unit is MB/sec. It's a ... | ||
50. Fitnesse framework very slow when folder depth is greater 4 - why? stackoverflow.comwe are currently establishing fitnesse as the testing tool user acceptance testing. so far everything is good. we are using the java version "20091121". we are having troubles with folders that ... | ||
51. Best OS to deploy a low latency Java application? stackoverflow.comWe have a low latency trading system (feed handlers, analytics, order entry) written in Java. It uses TCP and UDP extensively, it does not use Infiniband or other non-standard networking. Can ... | ||
52. Casting performance in Java stackoverflow.comI've a Servlet filter which performs the following type cast: | ||
53. Java framework for distributed system stackoverflow.comI am looking for a library (or a combination of libraries) to build a java distributed system, made of several applications exchanging data through several pairwise connections (no mapreduce). For the ... | ||
54. What is the performance difference, if any, between if(!foo) and if(foo == false) in Java? stackoverflow.comLogically, | ||
55. Slow CGLIB Performance using Callback Filters stackoverflow.comI'm noticing terrible speeds when trying to use CGLIB with a callback filter (on tens of thousands of objects) but I'm unable to find any information about optimizing CGLIB. For a search/list ... | ||
56. Tips to solve problem #41 of project euler stackoverflow.comI'm trying to solve Problem 41of project Euler in Java, by counting the number from 99888888 to 80000000(which took very long time :( ), I got 98765431 as ... | ||
57. How can i filtered with the best performance? (JAVA) stackoverflow.comI'm working at a small office,I have an application,it's generate a big text file with 14000 lines; after each generate i must filter it and it's really boring; I wanna write an application ... | ||
58. Why did java have the reputation of being slow? stackoverflow.comOk, this is not trolling. It's a real, technical question. Java has the reputation of being slow. There are jokes about it. I am not a great java user, the ... | ||
59. Is there any runtime cost for Casting in Java? stackoverflow.comWould there be any performance differences between these two chunks? | ||
60. Does Java casting introduce overhead? Why? stackoverflow.comIs there any overhead when we cast objects of one type to another? Or the compiler just resolves everything and there is no cost at run time? Is this a general things, ... | ||
61. get every two card combination from subset of standard deck stackoverflow.comI have a standard deck of cards and then have removed a few, from the remaining cards I want to calculate all of the possible two card combinations. For example with ... | ||
62. Finding the range in which a number lies stackoverflow.comI have the following method: | ||
63. Why Java is running faster than C here? stackoverflow.comInspired by this question, Now visible only for users with > 10k rep I came up with the following code: | ||
64. Compare bit sets efficiently stackoverflow.comI want to store permissions in a bit set to compare them efficiently in Java. A 1 would mean permission granted and 0 permission denied. If the authorization is performed the ... | ||
65. What is a good gc tuning strategy for gc output that I have? stackoverflow.comThis is the output after running for around 10 minutes. | ||
66. How to check if a parameter value is in a list of constants stackoverflow.comI have a list of constants and want to check if a value passed to a method equals one of the constants. I know Enums which would be fine, but I ... | ||
67. C/C++ versus Java/C# in high-performance applications stackoverflow.comMy Question is regarding performance of Java versus compiled code, for example C++/fortran/assembly in high-performance numerical applications. I know this is contentious topic, but I am looking for specific answers/examples. Also ... | ||
68. java short,integer,long performance stackoverflow.comi read that JVM stores internally short, integer and long as 4 bytes. this was an article from year 2000 so i don't know how true it is now. for the newer ... | ||
69. ' ... != null' or 'null != ....' best performance? stackoverflow.comI wrote two methods to check there performance | ||
70. Load Testing Multithreaded Java Application 1400 TPS Required stackoverflow.comI need to write a MultiThreaded Java Application that will be used to load test the MMS Server. Transactions starts when the MMS server indicates to my MultiThreaded Java Application that ... | ||
71. Java's varargs performance stackoverflow.comCoding i came around to check for the vararg performance of Java. I write following test code: | ||
72. best practice for passing many arguments to method? stackoverflow.comOccasionally , we have to write methods that receive many many arguments , for example : | ||
73. Does obfuscation affects performance? stackoverflow.comDoes obfuscating a Java program affect its performance (excluding renaming things)? | ||
74. game speed problem stackoverflow.comHI..I made a little game.But this game works on every computer with different speed.I think it is about resolution.I used every thing in paintcomponent.and If I change screen size the game ... | ||
75. Java repaint is slow under certain conditions stackoverflow.comI'm doing a simple grid which each square is highlighted by the cursor:
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76. VTD-XML Parsing Performance (speed critical factor). Requesting Feedback/Comments stackoverflow.comI am about to use VTD-XML (found at http://vtd-xml.sourceforge.net/) but I am interested in getting real-case usage feedback, by any one that has used the library and has any ... | ||
77. Ever any performance different between Java >> and >>> right shift operators? stackoverflow.comIs there ever reason to think the >> (signed) and >>> (unsigned) right bit-shift operators in Java would perform differently? I can't detect any difference on my machine. This is purely ... | ||
78. Response Time is different for mulitiple execution of the application with the same request Performance problem stackoverflow.comMy java application functionality is to provide reference data (basically loads lots of data from xml files into hashmap) and hence we request for one such data from the hashmap based ... | ||
79. calendar.getInstance() or calendar.clone() stackoverflow.comI need to make a copy of a given date 100s of times (I cannot pass-by-reference). I am wondering which of the below two are better options | ||
80. In Java, is there a performance gain in using interfaces for complex models? stackoverflow.comThe title is hardly understandable, but I'm not sure how to summarize that another way. Any edit to clarify is welcome. I have been told, and recommended to use interfaces to improve ... | ||
81. Java 1.4 to Java 6 migration stackoverflow.comI have some enterprise apps running on Java 1.4. They mostly invoke Stored Procedures on a DB, Parse XML files (at the most few megs large), read and write from and ... | ||
82. Performance: Iterating through a List in Java stackoverflow.comIs it slower to iterate through a list in Java like this: | ||
83. Drawing performance in Java 6 updates 19,20 versus Java 6 update 3? stackoverflow.comI'm getting twice the frame rate with the earlier Java 6 u 3, than with the new ones. Very weird. Can anyone give some explanation? On Core 2 Duo 1.83ghz, integrated video ... | ||
84. Java performance issue stackoverflow.comI've got a question related to java performance and method execution. In my app there are a lot of place where I have to validate some parameter, so I've written a Validator ... | ||
85. Use of private constructor to prevent instantiation of class? stackoverflow.comRight now I'm thinking about adding a private constructor to a class that only holds some | ||
86. How can we improve performance of this piece of code? stackoverflow.comHow to Improve performance of this chunk of code : | ||
87. Strange performance behaviour stackoverflow.comI'm puzzled with this. In my machine
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88. Why do finalizers have a "severe performance penalty"? stackoverflow.comEffective Java says : There is a severe performance penalty for using finalizers.Why is it slower to destroy an object using the finalizers? | ||
89. Java language convention; getters/setters stackoverflow.com | ||
90. java increase xmx dynamically at runtime stackoverflow.comI have a jvm server in my machine, now I want to have 2 apservers of mine sitting in same machine, however I want the standby one to have a really ... | ||
91. I'm asked to tune a long starting app into a short time period stackoverflow.comI'm asked to shorten the start-up period of a long starting app, however I have also to obligate to my managers to the amount of time i will reduce the startup ... | ||
92. Performance: float to int cast and clipping result to range stackoverflow.comI'm doing some audio processing with float. The result needs to be converted back to PCM samples, and I noticed that the cast from float to int is surprisingly expensive. Whats furthermore ... | ||
93. How can I disable Java garbage collector? stackoverflow.comwe have a PHP webapp that calls a java binary to produce a pdf report (with jasperreport), the java binary outpus pdf to standart output and exits, the php then send ... | ||
94. reasons why GcTimeLimit might not be erroring out? stackoverflow.comI have a web service in Java, contained in Jetty. I'm using Sun's Java 6 with the default ParallelGC, and I have the following command-line options turned on: "-verbose:gc -XX:+PrintGCTimeStamps --XX:+PrintGCDetails". When ... | ||
95. Updated resource for java performance tuning stackoverflow.comCan anyone recommend a web site that includes up to date performance tips for Java? Most of the sites I have found seem to be old and I guess the newer ... | ||
96. Does allocation speed depend on the garbage collector being used? stackoverflow.comMy app is allocating a ton of objects (>1mln per second; most objects are byte arrays of size ~80-100 and strings of the same size) and I think it might be ... | ||
97. Java: Calculate distance between a large number of locations and performance stackoverflow.comI'm creating an application that will tell a user how far away a large number of points are from their current position. Each point has a longitude and latitude. I've read over this ... | ||
98. Improving field get and set performance with ASM or Javassist stackoverflow.comI would like to avoid reflection in an open source project I am developing. Here I have classes like the following. | ||
99. Java anonymous class efficiency implications stackoverflow.comIs there any difference in efficiency (e.g. execution time, code size, etc.) between these two ways of doing things? Below are contrived examples that create objects and do nothing, but my actual ... | ||
100. Java JRE vs GCJ stackoverflow.comI have this results from a speed test I wrote in Java: |
They are a couple of JPanels, mapgrid and overlay inside a JLayeredPane, with mapgrid on the ...