JaCoCo Agent

import org.jacoco.agent.AgentJar;
import java.io.File;
import java.io.InputStream;
import java.io.IOException;
import java.net.URL;

import org.jacoco.agent.AgentJar;
import java.io.File;
import java.io.IOException;

// Get the agent JAR as a URL
URL agentUrl = AgentJar.getResource();

// Get the agent JAR as an InputStream
InputStream agentStream = AgentJar.getResourceAsStream();

// Extract agent to a temporary location
File tempAgent = AgentJar.extractToTempLocation();

// Extract agent to a specific location
File specificLocation = new File("/path/to/jacocoagent.jar");
AgentJar.extractTo(specificLocation);

/**
 * Returns a URL pointing to the JAR file.
 * @return URL of the JAR file
 */
public static URL getResource();

/**
 * Returns the content of the JAR file as a stream.
 * @return content of the JAR file
 */
public static InputStream getResourceAsStream();

// Access via URL
URL agentUrl = AgentJar.getResource();
InputStream stream = agentUrl.openStream();

// Direct stream access with proper resource management
try (InputStream agentStream = AgentJar.getResourceAsStream()) {
    // Use the stream for processing
    // Stream is automatically closed when try block exits
}

/**
 * Extract the JaCoCo agent JAR and put it into a temporary location. This
 * file should be deleted on exit, but may not if the VM is terminated
 * @return Location of the Agent Jar file in the local file system. The file
 *         should exist and be readable.
 * @throws IOException Unable to unpack agent jar
 */
public static File extractToTempLocation() throws IOException;

/**
 * Extract the JaCoCo agent JAR and put it into the specified location.
 * @param destination Location to write JaCoCo Agent Jar to. Must be writeable
 * @throws IOException Unable to unpack agent jar
 */
public static void extractTo(File destination) throws IOException;

// Extract to temporary location (automatically deleted on JVM exit)
File tempAgentFile = AgentJar.extractToTempLocation();
System.out.println("Agent extracted to: " + tempAgentFile.getAbsolutePath());

// Extract to specific location
File agentFile = new File("./jacocoagent.jar");
try {
    AgentJar.extractTo(agentFile);
    System.out.println("Agent extracted to: " + agentFile.getAbsolutePath());
} catch (IOException e) {
    System.err.println("Failed to extract agent: " + e.getMessage());
}

public final class AgentJar {
    // Private constructor - cannot be instantiated
    private AgentJar();
    
    // All methods are static
}

try {
    // Resource access - may throw AssertionError
    URL agentUrl = AgentJar.getResource();
    
    // File extraction - may throw IOException  
    File agentFile = new File("./jacocoagent.jar");
    AgentJar.extractTo(agentFile);
    
} catch (AssertionError e) {
    System.err.println("Agent resource not found. Check build configuration.");
} catch (IOException e) {
    System.err.println("Failed to extract agent: " + e.getMessage());
}

// Extract agent for use with JVM arguments
File agent = AgentJar.extractToTempLocation();
String javaagentArg = "-javaagent:" + agent.getAbsolutePath();
// Use javaagentArg when launching test JVMs

// Extract to build directory for distribution
File buildDir = new File("target/jacoco");
buildDir.mkdirs();
File agentJar = new File(buildDir, "jacocoagent.jar");
AgentJar.extractTo(agentJar);

// Use the built-in extraction method for deployment
File deploymentFile = new File("/path/to/deployment/jacocoagent.jar");
AgentJar.extractTo(deploymentFile);
// The extractTo method handles stream management and proper copying