JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null); The second line of code reports an error: java.lang.NullPointerExceptionThe cause of the problem is ToolProvider.getSystemJavaCompiler(); The obtained

Article DirectoryJAVA versionJAVA featuresJAVA environmentProject frameworkdos runJAVA versionjava SE winform C/S architecture (client and server) java EE B/S (processing of the website)Java 2me old version. Mobile Symbianandroid se + androidSdk management libraryopen sdk open source version numberJ

The error message is:Error: java: java.lang.ExceptionInInitializerError com.sun.tools.javac.code.TypeTagsIf you use Maven, the error message is the same.[INFO] ----------------------------------------------- ------------------------- [INFO] BUILD FAILURE [INFO] ----------------------------------------------- ------------------------- [INFO] Total time: 2.449 s [INFO] Finished at: 2020-02-26T08:34:45-05:00 [INFO] ----------------------------------------------- ------------------------- [ERROR] Fa

content1. What is Java1.2. Java related websites1.3. Development history1.4, Java composition2. What can Java doThird, the characteristics of the Java languageFourth, the first Java program4.1, install JDK and install4.2, configure environment variables4.2.1. Manual addition4.2.2, batch add one4.2.3

ylbtech-Java-Miscellaneous-java.nio: java.nioThe full name of java.nio is java non-blocking IO, which refers to the new api (New IO) provided in jdk1.4 and above. It provides data containers with caching support for all primitive types (except the boolean type). Use it to provide non-blocking IO. Bl

{Usage: java [-options] class [args...] (execution class) or java [-options] -jar jarfile [args...] (execution jar file) The options include: -d32 Use 32-bit data model ( (If available) -d64 use 64-bit data model (if available) -server select"server"VM default VM is server. -cp <class search path

java threadOne, thread status1. new: before the start() method is called after the thread is created using the new method2. Runnable: After the thread calls the start() method3. Non-runnable: the state caused by the thread being suspended or blocked, for exampleThread calls sleep()The thread calls w

java historyJava is the general term for Java object-oriented programming language and Java platform launched by Sun Microsystems in May 1995.It was jointly developed by James Gosling and his colleagues and officially launched in 1995.Java is a very popular computer programming language, of which ja

System.out.println("Java installation directory:"+System.getProperty("java.home"));System.out.println("Java version information:"+System.getProperty("java.version"));likecollectshareArticle reportTen kilograms of tears published 54 original articles, won praise1, visited 828 private messages and fol

Source of the article: hixue net agile and eager to learn forum www.piaodoo.com welcome everyone to learn from each otherFirst look at two pieces of code, one for Integer and one for AtomicInteger, as follows:public class Sample1 { private static Integer count = 0; synchronized public static void in