包含标签：Java 的文章
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java. Lang. IllegalStateException: assetmanager completed
I went to bed yesterday while my application was working, and today I couldn't start when I tried to run it Once I try…… -
Java – why Catalina home_ IS_ The undefined directory is generated by logback in the same project directory?
I wrote the logback configuration file for my application, but when I was doing Maven clean install (MVN clean install…… -
How do I use JNDI to pass parameters to an LDAP custom socket factory?
I am using JNDI to establish an LDAP connection Example: Hashtable env = new Hashtable(); env.put(Context.PROVIDER_URL…… -
Java – best practice for testing indexof return values
What do you usually write when testing the return value of indexof? if str.indexOf("a") < 0 VS if str.indexOf("a") …… -
Java – you cannot use expressions to increment byte values, but use the increment operator
See English answers > why byte + = 1 compile, but byte = byte + 1 not? 8 byte i=0; i++; The following is invalid by…… -
Strange behavior of Java scanner reading files
Therefore, I encountered an interesting problem when using the scanner class to read content from a file Basically, I'…… -
Java – what is the default temporaltype for temporal mapping keys without @ mapkeycolumn or @ mapkeytemporary annotations?
I am creating a JPA 2.0 annotation compliance kit for my internship I know that when you use @ mapkeycolumn to define …… -
ADO. Optimistic concurrency in net Entity Framework
I found that an MSDN article describes how EF handles concurrency when saving changes: I have two questions: >There…… -
Java – someone can explain spring security basepermission Create?
I'm developing a project involving spring security ACL, and I encountered creating permission basepermission CREATE. S…… -
Java – hibernate 5: generator class = “sequence” does not work properly
I have the following mappings: <id name="id" type="java.lang.Long" column="id"> <generator class="seq…… -
Java 9 repl for running applications
Java 9 introduced repl. Exe called jshell in the JDK distribution Is there any way to connect to the jshell of the JDK…… -
Criteria – multiple expressions in the JPA querybuilder where clause do not work
I'm using javax persistence. criteria. Criteriabuilder encountered a problem creating the query I am using eclipse lin…… -
Java – iterator of wildcard type variables with upper bound
Hello, I'm trying to extend HashMap < string, string > to enforce the "all lowercase" rule public class HttpQuer…… -
How to convert vectors in 1 row table in R
In R, I have a 1 - row table How do I convert it to a vector? Specifically, the table is as follows: 0 1 2 3 4 21…… -
Nutch: using java calls instead of the command line?
Am I thick or really unable to programmatically call Apache nutch through some java code? Where are the documents (or …… -
How to use java8 lambda expressions to throw exceptions for custom checks?
See English answers > java 8: lambda streams, filter by method with exception 13 private static void readStreamWith…… -
Java – create only one object for the class and reuse the same object
I want to create only one object of a class and reuse the same object over and over again How can I do this? Solution …… -
Java – change fonts of different lines in jtextarea
I want to add different font lines in jtextarea, but the last font seems to overwrite another font Please help import …… -
Java – Jenkins build fails with svnexception
I'm trying to run Jenkins build Here is my configuration Jenkins version: 1.445 deployment: as war Java: 1.7 (server 6…… -
Java – the key in treemap returns null
So I have a very strange mistake When I first used keyset () to iterate over the first 10 keys of a large treemap, I s…… -
Java – if there is no code: is it just an intellectual challenge or is it useful?
A friend of mine is discussing these design techniques for object state transformation (he is a Java master, by the wa…… -
Java – is it valid to get the logger from the static final variable initializer?
We have many class codes, and they have some templates as follows: private static Logger logger = null; private stati…… -
Java – ActiveMQ oom with stomp enabled
After enabling the stomp protocol on the ActiveMQ server (before it only enables the default protocol), it starts to f…… -
Migrate Jersey project to work in Jersey repackaged. org. objectweb. asm. Java. In classreader Java 10 result used in lang.illegalargumentexception
Previous projects run well on Tomcat 8 and JDK 8, but when I migrate my projects on Tomcat 9 and JDK 10, it gives the …… -
Emacs – Tuareg mode and CAML mode
I am currently using Tuareg mode, but I hope to be able to use the function of cam mode In particular, I want to be ab…… -
Java – how to ignore checkstyles on methods based on specific patterns
Does the checkstyle rule methodlength have a way to set the mode for the method to be ignored? I want to disable the c…… -
Java – why should you try to throw an unchecked exception on a checked exception?
See English answers > the case against checked exceptions 32 If I have this method title, two exceptions will be th…… -
com. sun. JNA and net java. What is the difference between dev.jna?
I'm looking at the central Maven repository and looking at net java. Dev.jna and com sun. jna groupId for JNA. JNA's G…… -
Java – calculates the nth floating point number
Using 32-bit floating-point numbers, I think there are floating-point numbers like 2 ^ 31 – 1 In Java, you can use an …… -
Implementation of observable pattern in Java
I am currently using the observer / observable pattern of Java. I want to know: In this way, if we want, we can use cl…… -
Model view controller – questions about Java EE 6 architecture
>From the above figure, I can conclude that Java EE 6 architecture is a 3-tier architecture What I don't understand…… -
Java recoverable hash calculation
I want to realize the recoverable instant hash generation of some files uploaded on the server The file is very large,……