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  • Drawing chunks, and positioning the camera

    - by Troubleshoot
    I've seen many questions and answers regarding how to draw tiled maps but I can't really get my head around it. Many answers suggest either loading the visible part of the map, or loading and unloading chunks of the map. I've decided the best option would be to load chunks, but I'm slightly confused as to how this would be implemented. Currently I'm loading the full map to a 2D array of buffered images, then drawing it every time repaint is called. Q1: If I were to load chunks of the map, would I load the map as a whole then draw the necessary chunk(s), or load & unload the chunks as the player moves along, and if so, how? My second question regards the camera. I want the player to be in the centre of the X axis and the camera to follow it. I've thought of drawing everything in relation to the map and calculating the position of the camera in relation to the players coordinates on the map. So, to calculate the camera's X position I understand that I should use cameraX = playerX - (canvasWidth/2), but how should I calculate the Y position? I want the camera to only move up when the player reaches cameraHeight/2 but to move down when the player reaches 3/4(cameraHeight). Q2: Should I check for this in the same way I check for collision, and move the camera relative to the movement of the player until the player stops moving, or am I thinking about it in the wrong way?

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  • Cycling through ItemStacks whlie supplying data... LOST [on hold]

    - by user3251606
    Ok so i am working on a plugin for my server that will open and inventory and when closed it will pass items to this class... object of this class is to cycle through the inventory and use a cfg file to define items and prices and then grab that info in a for loop and add it all up... heres what i have thus far... public void sell(Player p, Inventory inv) { ListIterator<ItemStack> it = inv.iterator(); double total = 0; for (ItemStack is : inv) { is = it.next(); if (is.getType() != null) { String type = is.getType().toString(); //short dur = is.getDurability(); String check = ChestSell.plugin.getConfig().getString(type); p.sendMessage("Item Type: " + type); if (check != null) { int amou = is.getAmount(); double value = ChestSell.plugin.getConfig().getDouble(type + ".price"); double tv = amou * value; p.sendMessage("Items in chest: Type " + type + " Ammount: " + amou + " Value: $" + tv); } //TODO Add return Items } } p.sendMessage("You got paid $" + total + " for your items!"); inv.clear(); }

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  • Building Website with JAX-RS (Jersey)

    - by 0xMG
    Is it discouraged/not-common to build Websites (not web-services!) using Jersey or any other JAX-RS implementation ? I didn't find any guide/tutorial/article regarding that.. At first impression , it seems to me that building website using Jersey (with JSPs as Viewables) is easier and more efficient than using Servlets & JSPs. If anyone did it before , I will be pleased to get tips, Do's & Don'ts, best practices etc... And maybe a good tutorial.

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  • How to swap or move 2 string in Array? [on hold]

    - by Wisnu Khazefa
    I have a need to convert .csv file to .dat file. In my problem, there are value pairs, with a name attribute (called Fund) and corresponding numeric value. If the input file has a pair whose value is 0, then that pair (Fund and value) is dropped. The output file should have only those pairs (Fund and value) where the value is non-zero. Here is the prototype of my code. public static void Check_Fund(){ String header = "Text1,Text2,Text3,FUND_UALFND_1,FUND_UALPRC_1,FUND_UALFND_2," +"FUND_UALPRC_2,FUND_UALFND_3,FUND_UALPRC_3,FUND_UALFND_4,FUND_UALPRC_4,FUND_UALFND_5,FUND_UALPRC_5,Text4,Text5,Text6,Text7"; String text = "ABC;CDE;EFG;PRMF;0;PRFF;50;PREF;0;PRCF;0;PRMP;50;TAHU;;BAKWAN;SINGKONG"; String[] head; String[] value; String showText = ""; head = header.split(","); value = text.split(";"); String regex = "\\d+"; String[] fund = {"PREF","PRMF","PRFF","PRCF","PRMP","PDFF","PSEF","PSCB","PSMF","PRGC","PREP"}; for(int i = 0; i < value.length; i++){ for(int j=0;j < fund.length; j++){ if(value[i].equals(fund[j]) && value[i+1].matches(regex)){ if(value[i+1].equals("0")){ value[i] = ""; value[i+1] = ""; } } } showText = showText + head[i] +":" + value[i] + System.lineSeparator(); } System.out.println(showText ); } Expected Result Input: FUND_UALFND_1:PRMF FUND_UALPRC_1:0 FUND_UALFND_2:PRFF FUND_UALPRC_2:50 FUND_UALFND_3:PREF FUND_UALPRC_3:0 FUND_UALFND_4:PRCF FUND_UALPRC_4:0 FUND_UALFND_5:PRMP FUND_UALPRC_5:50 Output: FUND_UALFND_1:PRFF FUND_UALPRC_1:50 FUND_UALFND_2:PRMP FUND_UALPRC_2:50 FUND_UALFND_0: FUND_UALPRC_0: FUND_UALFND_0: FUND_UALPRC_0: FUND_UALFND_0: FUND_UALPRC_0:

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  • How to remove items from an arraylist without shrinking the list [migrated]

    - by user73710
    I have a case where I am using the ArrayList to keep a list of items that are keyed by their position in the list. Other objects reference the ArrayList items by their position. If I delete one of the items from the list, I don't want the list to shrink because that would invalidate all other references to items in the list (e.g. item 2 is now in position 1). My solution to the shrinking array list problem is to null the position in the arraylist so that the list will not shrink. I am curious whether this will free the memory formerly held by the item at that position. If there is a better way to accomplish this requirement, I would like to know about it.

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  • Should I amortize scripting cost via bytecode analysis or multithreading?

    - by user18983
    I'm working on a game sort of thing where users can write arbitrary code for individual agents, and I'm trying to decide the best way to divide up computation time. The simplest option would be to give each agent a set amount of time and skip their turn if it elapses without an action being decided upon, but I would like people to be able to write their agents decision functions without having to think too much about how long its taking unless they really want to. The two approaches I'm considering are giving each agent a set number of bytecode instructions (taking cost into account) each timestep, and making players deal with the consequences of the game state changing between blocks of computation (as with Battlecode) or giving each agent it's own thread and giving each thread equal time on the processor. I'm about equally knowledgeable on both concurrency and bytecode stuff, which is to say not very, so I'm wondering which approach would be best. I have a clearer idea of how I'd structure things if I used bytecode, but less certainty about how to actually implement the analysis. I'm pretty sure I can work up a concurrency based system without much trouble, but I worry it will be messier with more overhead and will add unnecessary complexity to the project.

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  • hibernate criteria list problem [migrated]

    - by user1022676
    I have a user dao @Entity @Table(name="EBIGUSERTIM") public class EbigUser { private String id; private Integer source; private String entryscheme; private String fullName; private String email; private Long flags; private String status; private String createdBy; private Date createdStamp; private String modifiedBy; private Date modifiedStamp; @Id @Column(name="ID") public String getId() { return id; } public void setId(String id) { this.id = id; } @Id @Column(name="SOURCE") public Integer getSource() { return source; } public void setSource(Integer source) { this.source = source; } @Column(name="ENTRYSCHEME") public String getEntryscheme() { return entryscheme; } public void setEntryscheme(String entryscheme) { this.entryscheme = entryscheme; } @Column(name="FULLNAME") public String getFullName() { return fullName; } public void setFullName(String fullName) { this.fullName = fullName; } @Column(name="EMAIL") public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } @Column(name="FLAGS") public Long getFlags() { return flags; } public void setFlags(Long flags) { this.flags = flags; } @Column(name="STATUS") public String getStatus() { return status; } public void setStatus(String status) { this.status = status; } @Column(name="CREATEDBY") public String getCreatedBy() { return createdBy; } public void setCreatedBy(String createdBy) { this.createdBy = createdBy; } @Column(name="CREATEDSTAMP") public Date getCreatedStamp() { return createdStamp; } public void setCreatedStamp(Date createdStamp) { this.createdStamp = createdStamp; } @Column(name="MODIFIEDBY") public String getModifiedBy() { return modifiedBy; } public void setModifiedBy(String modifiedBy) { this.modifiedBy = modifiedBy; } @Column(name="MODIFIEDSTAMP") public Date getModifiedStamp() { return modifiedStamp; } public void setModifiedStamp(Date modifiedStamp) { this.modifiedStamp = modifiedStamp; } i am selecting 2 rows out of the db. The sql works select * from ebigusertim where id='blah'. It returns 2 distinct rows. When i query the data using hibernate, it appears that the object memory is not being allocated for each entry in the list. Thus, i get 2 entries in the list with the same object. Criteria userCriteria = session.createCriteria(EbigUser.class); userCriteria.add(Restrictions.eq("id", id)); userlist = userCriteria.list();

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  • Does low latency code sometimes have to be "ugly"?

    - by user997112
    (This is mainly aimed at those who have specific knowledge of low latency systems, to avoid people just answering with unsubstantiated opinions). Do you feel there is a trade-off between writing "nice" object orientated code and writing very fast low latency code? For instance, avoiding virtual functions in C++/the overhead of polymorphism etc- re-writing code which looks nasty, but is very fast etc? It stands to reason- who cares if it looks ugly (so long as its maintainable)- if you need speed, you need speed? I would be interested to hear from people who have worked in such areas.

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  • Problem in searching String array [on hold]

    - by user2573607
    I'm working on a bank interface project, where I have to search an array of string when the user types in his username. The array has 10 strings, but only the first string is recognized as a valid username...I'm positive that the syntax of the search technique(Linear Search) is correct, but I cannot seem to find the problem. The code however compiles properly. Any answer will be appreciated, TIA! Aparna

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  • How would I go about updating my electronic circuit simulator's 'electricity'?

    - by liqwidice
    I have made an application which allows the user to place down wires, power sources, and inverters on a virtual circuit board. All connections between tiles are automatic, as shown here: As you can see in the last image, the updating of power throughout this grid is not yet functioning. I think I understand how to do this updating conceptually, but getting it to work in my program is appearing to be much more difficult than I first imagined. My source code can be found here. If you have any tips as to how to I might approach this monstrous task, please let me know. EDIT The goal here is to simply get a working application. Getting tiles to pass on power to their neighbors is quite easy, but the tricky part is getting wires to "unpower" after the removal of a power source. The size of the grid is just 18x18, so efficiency really isn't a factor, for those wondering.

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  • how httpregistryfilter() in blackberry works?how to use [closed]

    - by Sowjanya
    i am trying to start my application using an url in my device browser. for this i used this: HttpFilterRegistry.registerFilter("www.atsas23.com","com.rim.samples.device.push"); Here this method will registry my application with www.atsas23.com and the second one will call the protocol class ,which is their in com.rim.samples.device.push. Now after doing ,still i am not getting .Means my app is not opening in browser.Can anybody tell why my application is not registering.what is going wrong.

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  • TileEntitySpecialRenderer only renders from certain angle

    - by Hullu2000
    I'm developing a Minecraft mod with Forge. I've added a tileentity and a custom renderer for it. The problem is: The block is only visible from sertain angles. I've compaed my code to other peoples code and it looks pretty much like them. The block is opaque and not to be rendered and the renderer is registered normally so the fault must be in the renderer. Here's the renderer code: public class TERender extends TileEntitySpecialRenderer { public void renderTileEntityAt(TileEntity tileEntity, double d, double d1, double d2, float f) { GL11.glPushMatrix(); GL11.glTranslatef((float)d, (float)d1, (float)d2); HeatConductTileEntity TE = (HeatConductTileEntity)tileEntity; renderBlock(TE, tileEntity.getWorldObj(), tileEntity.xCoord, tileEntity.yCoord, tileEntity.zCoord, mod.EMHeatConductor); GL11.glPopMatrix(); } public void renderBlock(HeatConductTileEntity tl, World world, int i, int j, int k, Block block) { Tessellator tessellator = Tessellator.instance; GL11.glColor3f(1, 1, 1); tessellator.startDrawingQuads(); tessellator.addVertex(0, 0, 0); tessellator.addVertex(1, 0, 0); tessellator.addVertex(1, 1, 0); tessellator.addVertex(0, 1, 0); tessellator.draw(); } }

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  • Slick UnicodeFont displays in different location depending on the screen size?

    - by Joehot2000
    I am using the Slick2D library to draw text. The text draws perfectly, however it is in the wrong location! I could easily draw it in the correct location, however the problem is that the "correct location" is very different depending on the size of the screen - And my game needs to be able to have the screen size changed. Here is the render method for the text: public static void render() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glDisableClientState(GL_VERTEX_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); glUseProgram(0); glBindBuffer(GL_ARRAY_BUFFER, 0); glMatrixMode(GL_PROJECTION); glLoadMatrix(orthographicProjectionMatrix); glMatrixMode(GL_MODELVIEW); glPushMatrix(); glLoadIdentity(); glDisable(GL_LIGHTING); font.drawString(0, 0, "OMG ITS TEXT!", Color.green); glEnable(GL_LIGHTING); glPopMatrix(); glMatrixMode(GL_PROJECTION); glLoadMatrix(perspectiveProjectionMatrix); glMatrixMode(GL_MODELVIEW); } So, how can I set the text to be in the middle of the screen irrespective of screen size? Thanks!

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  • SSL in tomcat with apr and Centos 6

    - by Jonathan
    I'm facing a problem setting up my tomcat with apr native lib, I have the following: Tomcat: 7.0.42 Java: 1.7.0_40-b43 OS: Centos 6.4 (2.6.32-358.18.1.el6.i686) APR: 1.3.9 Native lib: 1.1.27 OpenSSL: openssl-1.0.0-27.el6_4.2.i686 My server.xml looks like: ... <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" /> ... <Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true" maxThreads="150" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" SSLCertificateFile="/tmp/monitoringPortalCert.pem" SSLCertificateKeyFile="/tmp/monitoringPortalKey.pem" SSLPassword="hide" /> ... I compiled the native lib as follow: ./configure --with-apr=/usr/bin/apr-1-config --with-ssl=yes --prefix=$CATALINA_HOME make && make install The APR is loaded ok: Oct 06, 2013 7:55:14 PM org.apache.catalina.core.AprLifecycleListener init INFO: Loaded APR based Apache Tomcat Native library 1.1.27 using APR version 1.3.9. But I'm still having this error: SEVERE: Failed to initialize the SSLEngine. org.apache.tomcat.jni.Error: 70023: This function has not been implemented on this platform ./configure outcome [root@localhost native]# ./configure --with-apr=/usr/bin/apr-1-config --with-ssl=yes -- prefix=$CATALINA_HOME && make && make install checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-pc-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking for working mkdir -p... yes Tomcat Native Version: 1.1.27 checking for chosen layout... tcnative checking for APR... yes setting CC to "gcc" setting CPP to "gcc -E" checking for JDK location (please wait)... /usr/java/jdk1.7.0_40 from environment checking Java platform... checking Java platform... checking for sablevm... NONE adding "-I/usr/java/jdk1.7.0_40/include" to TCNATIVE_PRIV_INCLUDES checking os_type directory... linux adding "-I/usr/java/jdk1.7.0_40/include/linux" to TCNATIVE_PRIV_INCLUDES checking for gcc... gcc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking for OpenSSL library... using openssl from /usr/lib and /usr/include checking OpenSSL library version... ok checking for OpenSSL DSA support... yes setting TCNATIVE_LDFLAGS to "-lssl -lcrypto" adding "-DHAVE_OPENSSL" to CFLAGS setting TCNATIVE_LIBS to "" setting TCNATIVE_LIBS to " /usr/lib/libapr-1.la -lpthread" configure: creating ./config.status config.status: creating tcnative.pc config.status: creating Makefile config.status: executing default commands make[1]: Entering directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Nothing to be done for `local-all'. make[1]: Leaving directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Entering directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Nothing to be done for `local-all'. make[1]: Leaving directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' /usr/lib/apr-1/build/mkdir.sh /usr/apache-tomcat-7.0.42/include/apr-1 /usr/apache- tomcat-7.0.42/lib/pkgconfig \ /usr/apache-tomcat-7.0.42/lib /usr/apache-tomcat-7.0.42/bin /usr/bin/install -c -m 644 tcnative.pc /usr/apache-tomcat-7.0.42/lib/pkgconfig/tcnative- 1.pc list=''; for i in $list; do \ ( cd $i ; make DESTDIR= install ); \ done /bin/sh /usr/lib/apr-1/build/libtool --mode=install /usr/bin/install -c -m 755 libtcnative-1.la /usr/apache-tomcat-7.0.42/lib libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.so.0.1.27 /usr/apache- tomcat-7.0.42/lib/libtcnative-1.so.0.1.27 libtool: install: (cd /usr/apache-tomcat-7.0.42/lib && { ln -s -f libtcnative- 1.so.0.1.27 libtcnative-1.so.0 || { rm -f libtcnative-1.so.0 && ln -s libtcnative- 1.so.0.1.27 libtcnative-1.so.0; }; }) libtool: install: (cd /usr/apache-tomcat-7.0.42/lib && { ln -s -f libtcnative- 1.so.0.1.27 libtcnative-1.so || { rm -f libtcnative-1.so && ln -s libtcnative-1.so.0.1.27 libtcnative-1.so; }; }) libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.lai /usr/apache-tomcat- 7.0.42/lib/libtcnative-1.la libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.a /usr/apache-tomcat- 7.0.42/lib/libtcnative-1.a libtool: install: chmod 644 /usr/apache-tomcat-7.0.42/lib/libtcnative-1.a libtool: install: ranlib /usr/apache-tomcat-7.0.42/lib/libtcnative-1.a libtool: install: warning: remember to run `libtool --finish /usr/local/apr/lib' make && make install outcome: make[1]: Entering directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Nothing to be done for `local-all'. make[1]: Leaving directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Entering directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' make[1]: Nothing to be done for `local-all'. make[1]: Leaving directory `/usr/apache-tomcat-7.0.42/bin/tomcat-native-1.1.27- src/jni/native' /usr/lib/apr-1/build/mkdir.sh /usr/apache-tomcat-7.0.42/include/apr-1 /usr/apache- tomcat-7.0.42/lib/pkgconfig \ /usr/apache-tomcat-7.0.42/lib /usr/apache-tomcat-7.0.42/bin /usr/bin/install -c -m 644 tcnative.pc /usr/apache-tomcat-7.0.42/lib/pkgconfig/tcnative- 1.pc list=''; for i in $list; do \ ( cd $i ; make DESTDIR= install ); \ done /bin/sh /usr/lib/apr-1/build/libtool --mode=install /usr/bin/install -c -m 755 libtcnative-1.la /usr/apache-tomcat-7.0.42/lib libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.so.0.1.27 /usr/apache- tomcat-7.0.42/lib/libtcnative-1.so.0.1.27 libtool: install: (cd /usr/apache-tomcat-7.0.42/lib && { ln -s -f libtcnative- 1.so.0.1.27 libtcnative-1.so.0 || { rm -f libtcnative-1.so.0 && ln -s libtcnative- 1.so.0.1.27 libtcnative-1.so.0; }; }) libtool: install: (cd /usr/apache-tomcat-7.0.42/lib && { ln -s -f libtcnative- 1.so.0.1.27 libtcnative-1.so || { rm -f libtcnative-1.so && ln -s libtcnative-1.so.0.1.27 libtcnative-1.so; }; }) libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.lai /usr/apache-tomcat- 7.0.42/lib/libtcnative-1.la libtool: install: /usr/bin/install -c -m 755 .libs/libtcnative-1.a /usr/apache-tomcat- 7.0.42/lib/libtcnative-1.a libtool: install: chmod 644 /usr/apache-tomcat-7.0.42/lib/libtcnative-1.a libtool: install: ranlib /usr/apache-tomcat-7.0.42/lib/libtcnative-1.a libtool: install: warning: remember to run `libtool --finish /usr/local/apr/lib' It seems everything is fine, but the error is not self-explanatory Could you guys help to understand where my error is? What am I missing? Thanks in advance for your support.

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  • Package <blah> does not exist - NetBeans 6.8 & Windows 7

    - by bjmac
    I'm using NetBeans 6.8 on Windows 7. Upgrade from WinXP and NetBEans 6.7. Now my existing java web app project is no longer able to import/find the packages I've developed. And yet the project still compiles and runs OK. I've tried changing the Java Platform/JDK from 1.6.0_10 back to JDK 1.5.0_22 but I still receive errors package does not exist. All other libraries and packages are able to import OK ...

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  • GlassFish change port of web-service

    - by Dror
    Hi, I am new to Java and Linux. I have a JSP site and a java web service deployed on a GlassFish server (working OK). I need to change the port of both the application and web-service. I have changed the listener port in the domain.xml file, but the web application is still trying to connect to the WSDL on port 8080. How can I change the configuration of the web service port? Thanks

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  • set JAVA_HOME in windows but "ant build" still fails

    - by patrickinmpls
    I set JAVA_HOME in windows environment preferences echo %JAVA_HOME% C:\Program Files (x86)\Java\jdk1.6.0_20 but then I try to run ant build and I get Perhaps JAVA_HOME does not point to the JDK. It is currently set to "C:\Program Files\Java\jre6" I think the registry key JAVASOFT is interfering with my environment variable, but I'm not sure how to fix this

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  • How to determine JAVA_HOME on Debian/Ubuntu?

    - by Witek
    On Ubuntu it is possible to have multiple JVMs at the same time. The default one is selected with update-alternatives. But this does not set the JAVA_HOME environment variable, due to a debian policy. I am writing a launcher script (bash), which starts a java application. This java application needs the JAVA_HOME environment variable. So how to get the path of the JVM which is currently selected by update-alternatives?

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  • Is there a way to automatically keep Chrome/Ask Tool Bar from installing?

    - by hydroparadise
    So of lately, I've had to warn my users to watch out for unwanted programs that are coming in with Adobe Flash and Java updates. Adobe seems to be pushing Google's Chrome and Java with the Ask.com Toolbar. I admit that it could be much worse because both instance simply require an uncheck during some point of the update process, but on a large scale, prevention is better than confrontation. Any suggestions?

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  • Error:Unable to acsess jarfile

    - by user2539617
    Whenever I turn on my HP Pavilion slimline (type of computer) it says Error:Unable to acsess jarfile C:/Users/Private/Appdata/RoamingServer258261055 The tab name is Java Virtual Machine Launcher Somehow. This effects me connecting to java programs that require online on a downloaded platform such as .exe or .bin. So if you try to login on Minecraft it won't connect. Raidcall,Skype,Sony Vegas. I really need help!

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  • Synchronizing issue: I want the main thread to be run before another thread but it sometimes doesn´t

    - by Rox
    I have done my own small concurrency framework (just for learning purposes) inspired by the java.util.concurrency package. This is about the Callable/Future mechanism. My code below is the whole one and is compilable and very easy to understand. My problem is that sometimes I run into a deadlock where the first thread (the main thread) awaits for a signal from the other thread. But then the other thread has already notified the main thread before the main thread went into waiting state, so the main thread cannot wake up. FutureTask.get() should always be run before FutureTask.run() but sometimes the run() method (which is called by new thread) runs before the get() method (which is called by main thread). I don´t know how I can prevent that. This is a pseudo code of how I want the two threads to be run. //From main thread: Executor.submit().get() (in get() the main thread waits for new thread to notify) ->submit() calls Executor.execute(FutureTask object) -> execute() starts new thread -> new thread shall notify `main thread` I cannot understand how the new thread can start up and run faster than the main thread that actually starts the new thread. Main.java: public class Main { public static void main(String[] args) { new ExecutorServiceExample(); } public Main() { ThreadExecutor executor = new ThreadExecutor(); Integer i = executor.submit(new Callable<Integer>() { @Override public Integer call() { return 10; } }).get(); System.err.println("Value: "+i); } } ThreadExecutor.java: public class ThreadExecutor { public ThreadExecutor() {} protected <V> RunnableFuture<V> newTaskFor(Callable c) { return new FutureTask<V>(c); } public <V> Future<V> submit(Callable<V> task) { if (task == null) throw new NullPointerException(); RunnableFuture<V> ftask = newTaskFor(task); execute(ftask); return ftask; } public void execute(Runnable r) { new Thread(r).start(); } } FutureTask.java: import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.ReentrantLock; import java.util.logging.Level; import java.util.logging.Logger; public class FutureTask<V> implements RunnableFuture<V> { private Callable<V> callable; private volatile V result; private ReentrantLock lock = new ReentrantLock(); private Condition condition = lock.newCondition(); public FutureTask(Callable callable) { if (callable == null) throw new NullPointerException(); this.callable = callable; } @Override public void run() { acquireLock(); System.err.println("RUN"+Thread.currentThread().getName()); V v = this.callable.call(); set(v); condition.signal(); releaseLock(); } @Override public V get() { acquireLock(); System.err.println("GET "+Thread.currentThread().getName()); try { condition.await(); } catch (InterruptedException ex) { Logger.getLogger(FutureTask.class.getName()).log(Level.SEVERE, null, ex); } releaseLock(); return this.result; } public void set(V v) { this.result = v; } private void acquireLock() { lock.lock(); } private void releaseLock() { lock.unlock(); } } And the interfaces: public interface RunnableFuture<V> extends Runnable, Future<V> { @Override void run(); } public interface Future<V> { V get(); } public interface Callable<V> { V call(); }

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  • is it right to call ejb bean from thread by ThreadPoolExecutor?

    - by kislo_metal
    I trying to call some ejb bean method from tread. and getting error : (as is glassfish v3) Log Level SEVERE Logger javax.enterprise.system.std.com.sun.enterprise.v3.services.impl Name-Value Pairs {_ThreadName=Thread-1, _ThreadID=42} Record Number 928 Message ID java.lang.NullPointerException at ua.co.rufous.server.broker.TempLicService.run(TempLicService.java Complete Message 35) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) here is tread public class TempLicService implements Runnable { String hash; //it`s Stateful bean @EJB private LicActivatorLocal lActivator; public TempLicService(String hash) { this.hash= hash; } @Override public void run() { lActivator.proccessActivation(hash); } } my ThreadPoolExecutor public class RequestThreadPoolExecutor extends ThreadPoolExecutor { private boolean isPaused; private ReentrantLock pauseLock = new ReentrantLock(); private Condition unpaused = pauseLock.newCondition(); private static RequestThreadPoolExecutor threadPool; private RequestThreadPoolExecutor() { super(1, Integer.MAX_VALUE, 10, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>()); System.out.println("RequestThreadPoolExecutor created"); } public static RequestThreadPoolExecutor getInstance() { if (threadPool == null) threadPool = new RequestThreadPoolExecutor(); return threadPool; } public void runService(Runnable task) { threadPool.execute(task); } protected void beforeExecute(Thread t, Runnable r) { super.beforeExecute(t, r); pauseLock.lock(); try { while (isPaused) unpaused.await(); } catch (InterruptedException ie) { t.interrupt(); } finally { pauseLock.unlock(); } } public void pause() { pauseLock.lock(); try { isPaused = true; } finally { pauseLock.unlock(); } } public void resume() { pauseLock.lock(); try { isPaused = false; unpaused.signalAll(); } finally { pauseLock.unlock(); } } public void shutDown() { threadPool.shutdown(); } //<<<<<< creating thread here public void runByHash(String hash) { Runnable service = new TempLicService(hash); threadPool.runService(service); } } and method where i call it (it is gwt servlet, but there is no proble to call thread that not contain ejb) : @Override public Boolean submitHash(String hash) { System.out.println("submiting hash"); try { if (tBoxService.getTempLicStatus(hash) == 1) { //<<< here is the call RequestThreadPoolExecutor.getInstance().runByHash(hash); return true; } } catch (NoResultException e) { e.printStackTrace(); } return false; } I need to organize some pool of submitting hash to server (calls of LicActivator bean), is ThreadPoolExecutor design good idea and why it is not working in my case? (as I know we can`t create thread inside bean, but could we call bean from different threads? ). If No, what is the bast practice for organize such request pool? Thanks. << Answer: I am using DI (EJB 3.1) soo i do not need any look up here. (application packed in ear and both modules in it (web module and ejb), it works perfect for me). But I can use it only in managed classes. So.. 2.Can I use manual look up in Tread ? Could I use Bean that extends ThreadPoolExecutor and calling another bean that implements Runnable ? Or it is not allowed ?

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  • applet does not load

    - by jcp
    We have a legacy program that was ported from Java 1.3 to Java 1.5. This application involves applets which worked fine before. After porting however, the applet would not load. However there are no errors or exceptions. The app would just try to load it forever. We tried to run it with Java 1.6 and poof! No problems whatsoever. Isn't Java 6 backwards compatible? So how come it would run in that version and not in 1.5? ==== Java Console log for Java 1.5.0_19 basic: Registered modality listener basic: Registered modality listener basic: Registered modality listener liveconnect: Invoking JS method: document liveconnect: Invoking JS method: document liveconnect: Invoking JS method: document liveconnect: Invoking JS method: URL liveconnect: Invoking JS method: URL liveconnect: Invoking JS method: URL basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=1 basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=2 basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=3 basic: Added progress listener: sun.plugin.util.GrayBoxPainter@b0bad7 basic: Loading applet ... basic: Initializing applet ... basic: Starting applet ... basic: Added progress listener: sun.plugin.util.GrayBoxPainter@ba9340 basic: Added progress listener: sun.plugin.util.GrayBoxPainter@1198891 basic: Loading applet ... basic: Initializing applet ... basic: Starting applet ... basic: Loading applet ... basic: Initializing applet ... basic: Starting applet ... basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=4 basic: Releasing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=3 basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=4 basic: Releasing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=3 basic: Referencing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=4 basic: Releasing classloader: sun.plugin.ClassLoaderInfo@bb7759, refcount=3 network: Connecting <something>.jar with proxy=HTTP @ proxy/<ip address> basic: Loading <something>.jar from cache basic: No certificate info, this is unsigned JAR file. Left START init() Left END init() Right START init() Control start() Waiting for Left Panel to load... Right START start() network: Connecting socket://<ip address>:14444 with proxy=DIRECT Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... my HostName : <ip address> Thread-19 Check : Thread-19 Check : Monitor : run : start Thread-20 Monitor : Monitor: run() start Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... Control start() Waiting for Left Panel to load... the last message goes on forever... and now with the working version: ==== Java Console log for Java 1.6.0_15 basic: Added progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@1b000e7 basic: Added progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@12611a7 basic: Added progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@1807ca8 network: CleanupThread used 6 us network: CleanupThread used 5 us network: CleanupThread used 6 us cache: Skip blacklist check as cached value is ok. network: Cache entry found [url: <something>.jar, version: null] network: Connecting <something>.jar with proxy=HTTP @ proxy/<ip address> network: ResponseCode for <something>.jar : 304 network: Encoding for <something>.jar : null network: Disconnect connection to <something>.jar Reading certificates from 11 <something>.jar | <something>.idx network: No certificate info for unsigned JAR file: <something>.jar basic: Applet loaded. basic: Applet loaded. basic: Applet resized and added to parent container basic: Applet resized and added to parent container basic: PERF: AppletExecutionRunnable - applet.init() BEGIN ; jvmLaunch dt 330275 us, pluginInit dt 27768955 us, TotalTime: 28099230 us Right START init() basic: PERF: AppletExecutionRunnable - applet.init() BEGIN ; jvmLaunch dt 330275 us, pluginInit dt 27770563 us, TotalTime: 28100838 us Left START init() basic: Applet loaded. basic: Applet resized and added to parent container basic: PERF: AppletExecutionRunnable - applet.init() BEGIN ; jvmLaunch dt 330275 us, pluginInit dt 27779332 us, TotalTime: 28109607 us Left END init() basic: Applet initialized basic: Removed progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@12611a7 basic: Applet made visible And that's it. Still haven't figured out why it works with java6 and not java5. @valli: the object tag was used, not applet @thorbjorn: i tried that already... it just keeps saying loading applet... @aaron: how can i know what exception it is, if there really is one? and yes we have considered that its a java bug but i still havent found what that bug is. i have to submit a report tomorrow and i've scoured the net but came up with nothing as of yet... @all: thank you for your replies

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  • compile AMR-nb codec with RVCT for WinCE/Window Mobile

    - by pps
    Hello everybody, I'm working on amr speech codec (porting/optimization) I have an arm (for WinCE) optimized version from voiceage and I use it as a reference in performance testing. So far, binary produced with my lib beats the other one by around 20-30%! I use Vs2008 and I have limited access to ARM instruction set I can generate with Microsoft compiler. So I tried to look for alternative compiler to see what would be performance difference. I have RVCT compiler, but it produces elf binaries/object files. However, I run my test on a wince mobile phone (TyTn 2) so I need to find a way to run code compiled with RVCT on WinCE. Some of the options are 1) to produce assembly listing (-S option of armcc), and try to assemble with some other assembler that can create COFF (MS assembler for arm) 2) compile and convert generated ELF object file to COFF object (seems like objcopy of gnu binutils could help me with that) 3) using fromelf utility supplied by RVCT create BIN file and somehow try to mangle the bits so I can execute them ;) My first attempt is to create a simple c++ file with one exported function, compile it with RVCT and then try to run that function on the smartphone. The emitted assembly cannot be assembled by the ms assembler (not only they are not compatible, but also ms assembler rejects some of the instructions generated with RVCT compiler; ASR opcode in my case) Then I tried to convert ELF object to coff format and I can't find any information on that. There is a gcc port for ce and objcopy from that toolset is supposed to be able to do the task. However, I can't get it working. I tried different switches, but I have no idea what exactly I need to specify as bfdname for input and output format. So, I couldn't get it working either. Dumping with fromelf and using generated bin file seems to be overkill, so I decided to ask you guys if there is anything I should try to do or maybe someone has already done similar task and could help me. Basically, all I want to do is to compile my code with RVCT compiler and see what's the performance difference. My code has zero dependencies on any c runtime functions. thanks!

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