com.newrelic.bootstrap

Class BootstrapLoader

java.lang.Object

com.newrelic.bootstrap.BootstrapLoader

public class BootstrapLoader
extends java.lang.Object

Loads the agent-bridge, newrelic-api, and newrelic-bootstrap jars onto the bootstrap classpath.

Warning to maintainers: even slight changes to the code in this class can cause subtle failures at Agent startup time. The methods in this class modify the bootstrap classpath. Any change that causes bootstrap classes to be loaded before the bootstrap classpath changes are complete will result in said classes being loaded by the "wrong" classloader, potentially causing peculiar consequences later in execution. The existing dependencies (AgentJarHelper, JarResource, asm.ClassStructure) have been checked and don't result in undesirable classes being pulled into the "wrong" loader. Changes to dependencies must be understood and tested carefully. Dependencies on java.* are "safe". But in particular, do not introduce a dependency on the Logger here (it doesn't help anything, anyway, because the Logger has not been configured at this point in Agent startup).

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	AGENT_BRIDGE_DATASTORE_JAR_NAME
static java.lang.String	AGENT_BRIDGE_JAR_NAME
static java.lang.String	API_JAR_NAME
static java.lang.String	WEAVER_API_JAR_NAME

Constructor Summary

Constructors

Constructor and Description
BootstrapLoader()

Method Summary

Modifier and Type	Method and Description
static void	forceCorrectNewRelicApi(java.lang.instrument.Instrumentation instrProxy) This forces the correct NewRelic api implementation to load by getting the implementation class bytes out of the agent bridge jar and hooking up a class transformer to always load those bytes for our api class.
static java.net.URL	getDatastoreJarURL()
static java.util.Collection<java.net.URL>	getJarURLs() Returns URLs for the jars contained within the agent jar.
static java.io.File	getTempDir() Returns the tempdir that the agent should use, or null if the default temp directory should be used.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

AGENT_BRIDGE_JAR_NAME

public static final java.lang.String AGENT_BRIDGE_JAR_NAME

See Also:

Constant Field Values

AGENT_BRIDGE_DATASTORE_JAR_NAME

public static final java.lang.String AGENT_BRIDGE_DATASTORE_JAR_NAME

See Also:

Constant Field Values

API_JAR_NAME

public static final java.lang.String API_JAR_NAME

See Also:

Constant Field Values

WEAVER_API_JAR_NAME

public static final java.lang.String WEAVER_API_JAR_NAME

See Also:

Constant Field Values

Constructor Detail

BootstrapLoader

public BootstrapLoader()

Method Detail

forceCorrectNewRelicApi

public static void forceCorrectNewRelicApi(java.lang.instrument.Instrumentation instrProxy)
                                    throws java.io.IOException

This forces the correct NewRelic api implementation to load by getting the implementation class bytes out of the agent bridge jar and hooking up a class transformer to always load those bytes for our api class.

Throws:

java.io.IOException

getDatastoreJarURL

public static java.net.URL getDatastoreJarURL()
                                       throws java.lang.ClassNotFoundException,
                                              java.io.IOException

Throws:

java.lang.ClassNotFoundException

java.io.IOException

getJarURLs

public static java.util.Collection<java.net.URL> getJarURLs()
                                                     throws java.lang.ClassNotFoundException,
                                                            java.io.IOException

Returns URLs for the jars contained within the agent jar. These urls point to temp files created by writing the embedded jars out to disk. This method is used to ensure visibility of these embedded jars when the Agent is run from the command line. This code is not used when we initialize as an Agent via premain().

Returns:

URLs of certain jars embedded within the Agent jar

Throws:

java.lang.ClassNotFoundException

java.io.IOException

getTempDir

public static java.io.File getTempDir()

Returns the tempdir that the agent should use, or null if the default temp directory should be used. This can be set using the newrelic.tempdir system property.