APM - 使用JavaAgent+Javassit 插桩C3P0

野性酷女 2022-12-11 09:17 157阅读 0赞

### 文章目录 ###

*  核心思想
 *  编码实现
 *  打包
 *  配置验证

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70_pic_center]

# 核心思想 #

<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

1.  实时获取ComboPooledDataSource的属性信息
2.  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 #

<?xml version="1.0" encoding="UTF-8"?>
    <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-apm</artifactId>
            <groupId>org.example</groupId>
            <version>1.0-SNAPSHOT</version>
        </parent>
        <modelVersion>4.0.0</modelVersion>
    
        <artifactId>apm-agent</artifactId>
        <dependencies>
            <dependency>
                <groupId>org.javassist</groupId>
                <artifactId>javassist</artifactId>
                <version>3.18.1-GA</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
    
    
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.32</version>
                <scope>provided</scope>
            </dependency>
            <dependency>
                <groupId>c3p0</groupId>
                <artifactId>c3p0</artifactId>
                <version>0.9.1.2</version>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>2.2</version>
                    <configuration>
                        <archive>
                            <manifestEntries>
                                <Project-name>${project.name}</Project-name>
                                <Project-version>${project.version}</Project-version>
                                <Boot-Class-Path>javassist-3.18.1-GA.jar</Boot-Class-Path>
                                <Premain-Class>com.artisan.agent.collect.c3p0.C3P0Agent</Premain-Class>
                                <Can-Redefine-Classes>true</Can-Redefine-Classes>
                                <Can-Retransform-Classes>true</Can-Retransform-Classes>
                            </manifestEntries>
                        </archive>
                        <skip>true</skip>
                    </configuration>
                </plugin>
    
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                    <executions>
                        <execution>
                            <phase>package</phase>
                            <goals>
                                <goal>shade</goal>
                            </goals>
                            <configuration>
                                <artifactSet>
                                    <includes>
                                        <include>org.javassist:javassist</include>
                                    </includes>
                                </artifactSet>
                                <transformers>
                                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                        <mainClass>com.artisan.agent.collect.c3p0.C3P0Agent</mainClass>
                                    </transformer>
                                </transformers>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    
    
    
    </project>

**打包的时候，连同javassist也打包进去**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70_pic_center 1]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70_pic_center 2]  
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--------------------

# 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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70_pic_center 4]

然后，访问 http:// localhost:7777

![在这里插入图片描述][20200929231359934.png_pic_center]

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[20200929231359934.png_pic_center]: /images/20221123/8e13b06e77994568902448655d8a1547.png