elixir lang

Today, when I was working on struts, I encountered the java. Lang. nullpointerexception: module 'null' not found error. I was depressed for a long time, The Web. xml file is not configured./WEB-INF/struts-config2.xml If this problem occurs, try this method! It is inconvenient to change eclipse, and it is inconvenient to find the struts plug-in 3.1.2. I still think JBuilder is good...

Install go lang in CentOS 6.5)1. Set the system environment variable [plain] view plaincopyprint? Vi/etc/profile Add at the end (press the I key to enter the editing status, drag the cursor down, add the following, and then press: wq to save and exit, where: q! Is it forced to exit without saving) [plain] view plaincopyprint? ExportGOROOT =/usr/local/go ExportGOBIN = $ GOROOT/bin ExportGOPKG = $ GOROOT/pkg/tool/linux_amd64 ExportGOARCH

Java. lang. ThreadLocal 1. OverviewWhat is ThreadLocal? In fact, ThreadLocal is not a local implementation version of a Thread, it is not a thread, but Thread local variable (thread local variable ). It may be more appropriate to name it ThreadLocalVar. ThreadLocal provides a copy of the variable value for every thread that uses the variable. It is a special thread binding mechanism in Java, is that each thread can independently change its own copy, w

I. OverviewThe ProcessBuilder class is a new class added by J2SE 1.5 in java. lang. This class is used to create operating system processes. It provides a method to start and manage processes (that is, applications. Before J2SE 1.5, processes were controlled and managed by the Process class.Each ProcessBuilder instance manages a process property set. Its start () method uses these attributes to create a new Process instance. The start () method can be

Java. lang. NoClassDefFoundError: ognl/PropertyAccessor solution, ognl expression I didn't want to write a special article for this article, but I found that no one answered such a simple question. From the perspective of convenient search, I took this question specially. In fact, the solution is to add the jar package of ognl. For example, I use ognl3.0.6, as shown in: Struts2 cannot run. There is a pilot package, but it is 404 Struts2-gxp-plug

the type JAVA. lang. object cannot be resolved. it is indirectly referenced from required. class files This problem occurs when you reference JDK projects of different versions in eclipse. This is caused by the application of multiple JDK or JRE versions in your development environment. Eclipse selects the corresponding JRE by default according to the initial development environment. For example, there is an environment project de

as the following information: Java. Lang. illegalargumentexception: ID to load is required for loadingOrg. hibernate. event. loadevent. Org. hibernate. event. loadevent. Org. hibernate. impl. sessionimpl. Get (sessionimpl. Java: 812)Org. hibernate. impl. sessionimpl. Get (sessionimpl. Java: 808)Com. zyeeda. projs. cmsz. processors. testcasemoduleprocessor. Create (testcasemoduleprocessor. Java: 56)Org. Apache. jsp. test_005fcase_005fmodule.create_js

Recently, I am working on an e-book project to bring together the open-source shelves + ireader page flip and curl. I encountered the following problems when doing the curl effect: Java. Lang. Unsupported operation exception, Android. View. gles20canvas. clippath (gles20canvas... The omnipotent Gu Ge told me that this is a hardware acceleration problem, but I have never enabled hardware acceleration. I did a test and the hardware acceleration at the v

Today, we have an appwidget. To determine the WiFi and Bluetooth statuses, it takes some time to change the process status. Therefore, we need to open a thread to determine and then update the interface. A thread is opened directly to call the UPDATE function in the thread. Unfortunately, an error is prompted when you click Add appwidget for the first time. Java. Lang. runtimeexception: can't create handler inside thread that has not called logoff.

Today, we use middlegen to generate HBM for hibernate. XML and java files. After the graphical interface is displayed, click the "generate" button and throw the "Java. lang. the incompatibleclasschangeerror error is confusing. Baidu looked at it and it seems that there are like-minded people, just like me, who successfully generated HBM when they were used for the first time. an error occurs when you use the XML file again. Solution: there are multip

Problem: The shared variable simpledateformat is used in the multithreading method, and the following error is returned: Java. Lang. numberformatexception: multiple pointsAt sun. Misc. floatingdecimal. readjavaformatstring (floatingdecimal. Java: 1084 Cause:Simpledateformat is thread-insecure and should not be avoided! Solution: New simpledateformat (); Example: Simpledateformat SDF = new simpledateformat (); Class queryuserbynothread extends threa

I downloaded a SVN file on the server (which can be decompressed in ZIP format), decompressed it, and ran it. garbled characters:D: \ Server \ SVN \ bin> SVN ? \ 232? \ 175? \ 183? \ 228? \ 189? \ 191? \ 231? \ 148? \ 168? \ 226? \ 128? \ 156svn help? \ 226? \ 128? \ 157? \ 228? \ 187? \ 165? \ 229? \ 190? \ 151? \ 229? \ 136? \ 176? \ 231? \ 148? \ 168? \ 230? \ 179? \ 149? \ 229? \ 146? \ 140? \ 229? \ 184? \ 174? \ 229? \ 138? \ 169? \ 227? \ 128? /130 For example, if the environment vari

Http://blog.csdn.net/jxzxm1_2/article/details/2499751 An exception occurs when a Java program is used to query a large amount of data from the database:Java. Lang. outofmemoryerror: Java heap SpaceThis exception is thrown if 98% is used for GC and the available heap size is less than 2% in JVM.JVM heap setting refers to the setting of memory space that JVM can allocate during Java program running.The JVM automatically sets the heap size value at star

) java.net.URLClassLoader.findClass(URLClassLoader.java:188) java.lang.ClassLoader.loadClass(ClassLoader.java:306) java.lang.ClassLoader.loadClass(ClassLoader.java:299) sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276) java.lang.ClassLoader.loadClass(ClassLoader.java:299) java.lang.ClassLoader.loadClass(ClassLoader.java:251) java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) org.apache.jasper.runtime.JspFactoryImpl.getJspApplicationContext(JspFactor

MBThreadstacksize 32-bit JDK 1.6 default stacksize about KThe formula is as follows:(2*1024*1024-64*1024-130*1024)/325 = 5841The formula calculates 5841, which is basically the same as the practice 5602 (there is a deviation because reservedosmemory cannot be accurate) According to the formula, the more JVM memory you provide, the less threads you can create, and the more likely java. Lang. outofmemoryerror: Unable to create new Native thread. Callba

Java. Lang. illegalstateexception: getwriter () has already been called for this response Perform the followingCodeAn error is reported, Outputstream out = getresponse (). getoutputstream (); The reason is that response. getwriter () is opened in the Code and is not closed. It is difficult to troubleshoot one by one because there are many call points. View the code and see usingwriter = true in response. Then you can set this flag to false. Res

Import Java. util. arrays; import Java. util. list; import Java. util. arraylist; public class stringarraytest {publicstatic void main (string [] ARGs) {string [] words = {"Ace", "boom", "crew", "dog ", "Eon"}; List When arrays. aslist () is used and the add and remove methods are calledJava. Lang. unsupportedoperationexceptionException. This is because arrays. aslist () returns java. util. arrays $ arraylist instead of arraylist. Arrays $ array

Actually. I made a mistake when calling a function at the DaO layer. I called myself. A java. Lang. stackoverflowerror error occurs in the recently executed project. After a long time, I also asked experts and checked information. Finally, the problem is solved! Special record! Stackoverflowerror is because the current thread's stack is fullWhich is caused by too many function call levels. For example, dead recursion. For example: Public Str

I am using Tomcat addon of XAMPP. The following error occurs when running the JSP Example That comes with Tomcat: Ava. Lang. unsupportedclassversionerror: bad version number in. Class File JDK on my machine is .. 0_10. The location is as follows: Set java_home = C:/program files/Java/jdk1.6.0 _ 10 The JDK used for Tomcat is still 1.5. Solution: Modify the JDK directory of Tomcat Open tomcat/bin/Catalina. BAT and fi

The external android project is imported to ecplise. The compilation is normal and an error is returned. The logcat is as follows: 12-19 10:55:25. 915: E/AndroidRuntime (2929): fatal exception: main12-19 10:55:25. 915: E/AndroidRuntime (2929): java. lang. noClassDefFoundError: com. guet. siriCN. mainActivity $1 www.2cto. com12-19 10:55:25. 915: E/AndroidRuntime (2929): at com. XXX. mainActivity.