<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" ......
很熟悉吧，我们要插桩的这个对象就是 ComboPooledDataSource ，
如何很直观的展示出来的
- 实时获取ComboPooledDataSource的属性信息
- 简洁直观的展示相关属性信息
实现第一个，那就在ComboPooledDataSource构造函数后下手，将ComboPooledDataSource放到System Properties 中， 然后开启一个HTTP服务，对外提供服务访问即可。
编码实现
package com.artisan.agent.collect.c3p0;import com.sun.net.httpserver.Headers;import com.sun.net.httpserver.HttpExchange;import com.sun.net.httpserver.HttpHandler;import com.sun.net.httpserver.HttpServer;import javassist.ClassPool;import javassist.CtClass;import javassist.LoaderClassPath;import java.io.IOException;import java.io.OutputStream;import java.lang.instrument.ClassFileTransformer;import java.lang.instrument.Instrumentation;import java.net.InetSocketAddress;import java.security.ProtectionDomain;import java.util.concurrent.Executors;/**
* @author 小工匠
* @version 1.0
* @description: C3P0插桩
* @date 2020/8/29 9:15
* @mark: show me the code , change the world
*/public class C3P0Agent {
// 要插装的类
static String targetClass = "com.mchange.v2.c3p0.ComboPooledDataSource";
public static void premain(String args , Instrumentation instrumentation){
// 类转换器处理插桩逻辑
instrumentation.addTransformer(new ClassFileTransformer() {
public byte[] transform(ClassLoader loader,
String className,
Class<?> classBeingRedefined,
ProtectionDomain protectionDomain,
byte[] classfileBuffer) {
// 插桩后的对象
byte[] result = null;
// 条件判断
if (className != null && className.replace("/", ".").equals(targetClass)){
// 实例化pool , 将当前的ClassLoader设置到pool
ClassPool pool = new ClassPool();
pool.insertClassPath(new LoaderClassPath(loader));
try {
// 获取目标对象
CtClass ctl = pool.get(targetClass);
// 获取构造函数，插桩 将对象放入系统属性中
ctl.getConstructor("()V") //构造函数
.insertAfter("System.getProperties().put(\"c3p0Source$agent\", $0);"); // $0 this本身
// 转成class
result = ctl.toBytecode();
// 暴漏HTTP服务
new C3P0Agent().openHttpServer();
} catch (Exception e) {
e.printStackTrace();
}
}
return result;
}
});
}
/**
* 对外提供Http 服务展示DataSource当前状态
* @throws IOException
*/
private void openHttpServer() throws IOException {
InetSocketAddress addr = new InetSocketAddress(7777);
HttpServer server = HttpServer.create(addr, 0);
// 设置上下文
server.createContext("/", new MyHttpHandler());
server.setExecutor(Executors.newCachedThreadPool());
server.start();
}
private class MyHttpHandler implements HttpHandler {
@Override
public void handle(HttpExchange exchange) throws IOException {
Headers responseHeaders = exchange.getResponseHeaders();
responseHeaders.set("Content-Type", "text/plain;charset=UTF-8");
exchange.sendResponseHeaders(200, 0);
OutputStream responseBody = exchange.getResponseBody();
// 输出c3p0状态
responseBody.write(C3P0Agent.this.getStatus().getBytes());
responseBody.flush();
responseBody.close();
}
}
public String getStatus() {
Object source2 = System.getProperties().get("c3p0Source$agent");
if (source2 == null) {
return "未初始任何c3p0数据源";
}
return source2.toString();
}}
打包
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>artisan-apmartifactId>
<groupId>org.examplegroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>apm-agentartifactId>
<dependencies>
<dependency>
<groupId>org.javassistgroupId>
<artifactId>javassistartifactId>
<version>3.18.1-GAversion>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.12version>
<scope>testscope>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
<scope>providedscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.32version>
<scope>providedscope>
dependency>
<dependency>
<groupId>c3p0groupId>
<artifactId>c3p0artifactId>
<version>0.9.1.2version>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-jar-pluginartifactId>
<version>2.2version>
<configuration>
<archive>
<manifestEntries>
<Project-name>${project.name}Project-name>
<Project-version>${project.version}Project-version>
<Boot-Class-Path>javassist-3.18.1-GA.jarBoot-Class-Path>
<Premain-Class>com.artisan.agent.collect.c3p0.C3P0AgentPremain-Class>
<Can-Redefine-Classes>trueCan-Redefine-Classes>
<Can-Retransform-Classes>trueCan-Retransform-Classes>
manifestEntries>
archive>
<skip>trueskip>
configuration>
plugin>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-shade-pluginartifactId>
<executions>
<execution>
<phase>packagephase>
<goals>
<goal>shadegoal>
goals>
<configuration>
<artifactSet>
<includes>
<include>org.javassist:javassistinclude>
includes>
artifactSet>
<transformers>
<transformer
implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>com.artisan.agent.collect.c3p0.C3P0AgentmainClass>
transformer>
transformers>
configuration>
execution>
executions>
plugin>
plugins>
build>project>
打包的时候，连同javassist也打包进去
配置验证
在启动的JVM参数中配置如下信息
-javaagent:D:\IdeaProjects\artisan-apm\apm-agent\target\apm-agent-1.0-SNAPSHOT.jar
然后，访问 http:// localhost:7777