urlclassloader

Using URLClassLoader to load .class file

我只是一个虾纸丫 提交于 2021-02-05 05:55:05
问题 I'm aware that this question has been asked before: How to use URLClassLoader to load a *.class file? However I don't really understand due to the lack of example. I'm currently working on a project and trying to load user-given .class objects which can be located in any directories on the machine. //Create URL to hash function class file URL url_hashFunctionPath = new URL("file:///" + _sHashFunctionFilePath); //Packet URL to a URL array to be used by URLClassLoader URL[] urlA

Manifest.mf and imports

生来就可爱ヽ(ⅴ<●) 提交于 2020-04-16 05:50:33
问题 I have the following dynamodb.jar structure, where lib/ has a bunch of .jar s. All these nested .jar s are needed by com.mparnisa.dynamodb.table . From another IntelliJ project I am trying to instantiate a class within this dynamodb.jar : try { File file = new File("<path>/dynamo.jar"); URL url = file.toURI().toURL(); URL[] urls = new URL[]{url}; ClassLoader urlClassLoader = new URLClassLoader(urls); String resourceModelClassName = "com.mparnisa.dynamodb.table.ResourceModel"; Class<?>

Manifest.mf and imports

人盡茶涼 提交于 2020-04-16 05:50:17
问题 I have the following dynamodb.jar structure, where lib/ has a bunch of .jar s. All these nested .jar s are needed by com.mparnisa.dynamodb.table . From another IntelliJ project I am trying to instantiate a class within this dynamodb.jar : try { File file = new File("<path>/dynamo.jar"); URL url = file.toURI().toURL(); URL[] urls = new URL[]{url}; ClassLoader urlClassLoader = new URLClassLoader(urls); String resourceModelClassName = "com.mparnisa.dynamodb.table.ResourceModel"; Class<?>

轻松搞定jvm类加载器

余生长醉 提交于 2020-03-01 09:20:12
什么是类的加载 我们平时所编写的“xx.java”文件需要经过我们所知的java编译器(javac)编译成“xx.class”文件,这个文件存放着编译后jvm指令的的二进制信息。而**当我们需要用到某个类时,jvm将会加载它,并在内存中创建对应的class对象,这个过程称之为类的加载。**过程如下: 类的加载、连接、初始化 1. 加载 通过类的包名和雷鸣查找到此类的字节码文件,将xx.class文件中的二进制数据读入到jvm内存,并存入其中的方法区内,然后利用字节码文件创建一个class对象存入到堆之中,用来封装类的数据结构等。 连接(验证、准备、解析): 2. 连接包括三步: 验证:确保被加载类的正确性,是否对jvm有害 准备:为**类的静态变量(static)**分配内存并将其赋值为默认变量(非赋值)eg:static int a = 1;(为a分配内存并设置为0,将a赋值为1的动作是在初始化过程中完成的,而final static int a = 1赋值是在javac过程中完成的。) 解析:把类中的符号引用转化为直接引用,符号引用:我们所写的int a 就是符号引用,直接引用:目标的指针、偏移量内存中的引用,类似c/c++中的指针。 3. 初始化 如果有父类,此时加载父类并进行初始化,静态变量、成员变量等,再加载子类。 类加载器 类的加载是由类加载器完成的

Load jar dynamically

ε祈祈猫儿з 提交于 2020-01-11 12:56:10
问题 In my java application, I read a jar file (packaged with Maven shade plugin) into a bytestream. In the jar there is a entrypoint class defined in POM.xml <build> ... <plugins> ... <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <configuration> <archive> <manifest> <mainClass>com.mycompany.TheEntryPoint</mainClass> </manifest> </archive> </configuration> </plugin> </plugins> </build> How do I load such class into my java app dynamically? Update:

URLClassLoader Memory Leak Java

守給你的承諾、 提交于 2020-01-06 21:01:09
问题 I have been going through a lot of URLClassLoader Memory leak solutions on the internet, but I haven't found any fully working code and precise solution. The closest to a solution I found was this Any fully functional code or link to it, which uses WeakHashMap() or any other definite way of eliminating memory leak problem on multiple redeploys? 回答1: just add the dependency of class loader leak preventer in your build path. maven dependency for this is : <!-- For Classloader leak protection --

Load class within Jar file and get it's path

◇◆丶佛笑我妖孽 提交于 2020-01-06 01:47:30
问题 I know there are already a lot similar questions here, but I couldn't get any smarter form them. I want to load a class inside a jar file, at this point this is no problem, but when I want to pass the path to my own ClassLoader it throws an exception it cannot find the class. Is it possible to load a class inside a jar using an absolute path? For instance, Class cls = loader.loadClass(/path/MyPlugin.jar/MyPlugin.class); But when I do this: File test = new File("path/plugins/MyPlugin.jar

ClassNotFoundException while loading a class from file with URLClassLoader

社会主义新天地 提交于 2020-01-05 02:51:27
问题 I am using the following code to create an instance of OdbcIniTarget class which implements the Target interface. The OdbcIniTarget class already exists in the application but is located in a different package and now should be loaded from the target directory which is not in the class path. ... // directory below is resolved to /D:/Workspace/<myproject>/targets/ private File targetsLocation = new File("targets"); ... private void loadTargets() { URL url = null; try { url = targetsLocation

ClassNotFoundException while loading a class from file with URLClassLoader

十年热恋 提交于 2020-01-05 02:50:27
问题 I am using the following code to create an instance of OdbcIniTarget class which implements the Target interface. The OdbcIniTarget class already exists in the application but is located in a different package and now should be loaded from the target directory which is not in the class path. ... // directory below is resolved to /D:/Workspace/<myproject>/targets/ private File targetsLocation = new File("targets"); ... private void loadTargets() { URL url = null; try { url = targetsLocation

Java keeping jar in use by jarclassloader/urlclassloader

夙愿已清 提交于 2020-01-04 14:09:04
问题 I am loading a jar file with a JarClassLoader . After the jar file is loaded, I want to delete the file. Everything works fine except for deleting the file because the file is kept in use by the Java jvm. How do I unlock the jar? I am already closing all my inputstreams and closing the urlclassloader . Thank you, Ridz 来源: https://stackoverflow.com/questions/18834432/java-keeping-jar-in-use-by-jarclassloader-urlclassloader