Victor Bello Victor Bello - 2 months ago 21
Java Question

Compile dynamically java class web project

I'm developing a web application where I can import a java code, compile and then execute it.
This class might have some imports from another libraries, which I added to my classpath.
Running it as a desktop application, it works, but running under wildfly 9.0.2 it doesn't find my classpath libs and so, I have errors to compile my code.

Do I have to change any setting on wildfly configuration? I tried my code with and without maven.

I'm using this lib to compile my code, and like I said, it worked using the app like desktop: https://github.com/trung/InMemoryJavaCompiler

Errors:

13:44:57,686 ERROR [stderr] (default task-5) /br/com/project/webtest/service/CompileClass.java:2: error: package org.junit does not exist
13:44:57,686 ERROR [stderr] (default task-5) import static org.junit.Assert.*;
13:44:57,686 ERROR [stderr] (default task-5) ^
13:44:57,687 ERROR [stderr] (default task-5) /br/com/project/webtest/service/CompileClass.java:3: error: cannot find symbol
13:44:57,687 ERROR [stderr] (default task-5) import br.com.project.webtest.service.SeleniumService;
13:44:57,688 ERROR [stderr] (default task-5) ^
13:44:57,688 ERROR [stderr] (default task-5) symbol: class SeleniumService
13:44:57,688 ERROR [stderr] (default task-5) location: package br.com.project.webtest.service
13:44:57,689 ERROR [stderr] (default task-5) /br/com/project/webtest/service/CompileClass.java:4: error: package org.junit does not exist
13:44:57,689 ERROR [stderr] (default task-5) import org.junit.*;


The error messages continues with all others import libs
and then, the classformaterror:

13:44:57,751 WARNING [javax.enterprise.resource.webcontainer.jsf.lifecycle] (default task-5) #{testController.action()}: java.lang.ClassFormatError: Truncated class file: javax.faces.FacesException: #{testController.action()}: java.lang.ClassFormatError: Truncated class file


Edit:
I added using eclipse mars, under the Webcontent/web-inf/lib folder, added my libs and right click, add to build path.

Edit 2:
Class responsible for creating the code and get the result:

package br.com.test;

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean
@SessionScoped
public class TestController {

public void actionParent() {
String javaCode = generateJavaCode();
Class<?> compile = null;
try {
compile = InMemoryCompilerTest.compile(Thread.currentThread().getContextClassLoader(),
"br.com.project.webtest.service.CompileClass", javaCode);
System.out.println("Worked: " + compile);
} catch (Exception e) {
e.printStackTrace();
}
}

public void actionClassLoader() {
String javaCode = generateJavaCode();
Class<?> compile = null;
try {
compile = InMemoryCompilerTest.compile("br.com.project.webtest.service.CompileClass", javaCode);
System.out.println("Worked: " + compile);
} catch (Exception e) {
e.printStackTrace();
}
}

static String readFile(String path, Charset encoding) throws IOException {
byte[] encoded = Files.readAllBytes(Paths.get(path));
return new String(encoded, encoding);
}

private static String generateJavaCode() {
String java = "package br.com.project.webtest.service;\r\n"
+ "import static org.junit.Assert.*;\r\n"
+ "public class CompileClass {\r\n"
+ " public CompileClass() {\r\n"
+ " System.out.println(\"Dynamically compiled\");\r\n"
+ " String text = \"Testing JUnit lib\";\r\n"
+ " assertEquals(\"Testing JUnit lib\", text);\r\n"
+ " System.out.println(\"completed\");\r\n"
+ " }\r\n" + " public static void main(String[] args) {\r\n"
+ " new CompileClass();\r\n"
+ " System.out.println(\"finish\");\r\n"
+ " }\r\n"
+ "}\r\n";

return java;

}

public static void main(String[] args) {
TestController c = new TestController();
c.actionClassLoader();
c.actionParent();
}

}


I created a class which extends the lib and changed use parent classloader:

public class InMemoryCompilerTest extends InMemoryJavaCompiler {
static JavaCompiler javac = ToolProvider.getSystemJavaCompiler();

public static Class<?> compile(ClassLoader parent, String className, String sourceCodeInText) throws Exception {
SourceCode sourceCode = new SourceCode(className, sourceCodeInText);
CompiledCode compiledCode = new CompiledCode(className);
Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(sourceCode);
DynamicClassLoader cl = new DynamicClassLoader(parent);
ExtendedStandardJavaFileManager fileManager = new ExtendedStandardTest(
javac.getStandardFileManager(null, null, null), compiledCode, cl);
JavaCompiler.CompilationTask task = javac.getTask(null, fileManager, null, null, null, compilationUnits);
boolean result = task.call();
return cl.loadClass(className);
}
}

public class ExtendedStandardTest extends ExtendedStandardJavaFileManager{

protected ExtendedStandardTest(JavaFileManager fileManager, CompiledCode compiledCode, DynamicClassLoader cl) {
super(fileManager, compiledCode, cl);
}

}


xhtml:

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html">

<h:head></h:head>
<h:body>

<h:form>

<h:commandButton action="#{testController.actionClassLoader()}" value="ClassLoader" />
<h:commandButton action="#{testController.actionParent()}" value="Parent" />
</h:form>
</h:body>
</html>


I tested passing parent classloader as you sugested but also didnt work.

The first class "TestController" executing from main method it works.

Edit:

I have added the following code where I can set the classpath with my libs:

// set the classpath
List<String> options = new ArrayList<String>();

options.add("-classpath");
StringBuilder sb = new StringBuilder();
URLClassLoader urlClassLoader = (URLClassLoader) parent;

for (URL url : urlClassLoader.getURLs()) {
sb.append(url.getFile()).append(File.pathSeparator);
}
options.add(sb.toString());


Executing as a Java application it returns:

[-classpath, /C:/Users/dev/Automacao/workspace/test/build/classes/;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/InMemoryJavaCompiler-1.2.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/commons-io-2.5.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/client-combined-3.0.0-beta3-nodeps.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/commons-codec-1.10.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/commons-exec-1.3.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/commons-logging-1.2.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/gson-2.3.1.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/guava-19.0.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/hamcrest-core-1.3.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/hamcrest-library-1.3.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/httpclient-4.5.2.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/httpcore-4.4.4.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/httpmime-4.5.2.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/jna-4.1.0.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/jna-platform-4.1.0.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/junit-4.12.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/netty-3.5.7.Final.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/phantomjsdriver-1.3.0.jar;/C:/Users/dev/Automacao/workspace/test/WebContent/WEB-INF/lib/workspace_libs/cglib-nodep-3.2.4.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/annotations-api.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/catalina-ant.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/catalina-ha.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/catalina-storeconfig.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/catalina-tribes.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/catalina.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/ecj-4.3.1.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/el-api.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/jasper-el.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/jasper.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/jsp-api.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/servlet-api.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-api.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-coyote.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-dbcp.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-i18n-es.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-i18n-fr.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-i18n-ja.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-jdbc.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-jni.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-spdy.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-util-scan.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-util.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/tomcat-websocket.jar;/C:/Program%20Files/Apache%20Software%20Foundation/Apache%20Tomcat%208.0.3/lib/websocket-api.jar;/C:/Users/dev/Automacao/workspace/libraries/JSF%202.2%20(Mojarra%202.2.0)/mojarra-2.2.0-FCS/lib/javax.faces.jar;]


Executing as webapplication:

[-classpath, /C:/Users/dev/Automacao/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/test/WEB-INF/classes/;/C:/Users/dev/Automacao/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/test/WEB-INF/lib/commons-io-2.5.jar;/C:/Users/dev/Automacao/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/test/WEB-INF/lib/InMemoryJavaCompiler-1.2.jar;/C:/Users/dev/Automacao/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/test/WEB-INF/lib/javax.faces.jar;]


How could I get the same result?

Answer

Get it working.

I have to make that change mentioned by @NicolasFilotto, to use parent classloader when using a webapp. After that, for JavaCompiler works, as I'm using external libraries it's necessary to pass my classpath like mentioned on my last edit. Basically the code changed to:

public static Class<?> compile(ClassLoader parent, String className, String sourceCodeInText) throws Exception {
        SourceCode sourceCode = new SourceCode(className, sourceCodeInText);
        CompiledCode compiledCode = new CompiledCode(className);
        Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(sourceCode);
        DynamicClassLoader cl = new DynamicClassLoader(parent.getParent());
        ExtendedStandardJavaFileManager fileManager = new ExtendedStandard(
                javac.getStandardFileManager(null, null, null), compiledCode, cl);

        // set the classpath
        List<String> options = new ArrayList<String>();

        options.add("-classpath");
        StringBuilder sb = new StringBuilder();
        Enumeration<URL> resources = parent.getResources("/");
        while (resources.hasMoreElements()) {
            URL url = resources.nextElement();
            sb.append(url.getFile()).append(File.pathSeparator);
        }

        options.add(sb.toString());

        // execute the compiler
        Boolean call = javac.getTask(null, fileManager, null, options, null, compilationUnits).call();
        if (call) {
            return cl.loadClass(className);
        }
        return null;
    }

Using wildfly I had to change URLClassLoader urlClassLoader = (URLClassLoader) parent; to Enumeration<URL> resources = parent.getResources("/");

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