add demo

spring-boot-agent/pom.xml

@@ -21,29 +21,9 @@
 
     <dependencies>
         <dependency>
-            <groupId>com.secoo.mall</groupId>
-            <artifactId>secoo-log-starter</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-test</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-aop</artifactId>
-        </dependency>
-
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-autoconfigure</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-actuator</artifactId>
+            <groupId>javassist</groupId>
+            <artifactId>javassist</artifactId>
+            <version>3.11.0.GA</version>
         </dependency>
     </dependencies>
 
@@ -68,6 +48,25 @@
                         <target>${java.version}</target>
                     </configuration>
                 </plugin>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-shade-plugin</artifactId>
+                    <executions>
+                        <execution>
+                            <phase>package</phase>
+                            <goals>
+                                <goal>shade</goal>
+                            </goals>
+                        </execution>
+                    </executions>
+                    <configuration>
+                        <artifactSet>
+                            <includes>
+                                <include>javassist:javassist:jar:</include>
+                            </includes>
+                        </artifactSet>
+                    </configuration>
+                </plugin>
             </plugins>
         </pluginManagement>
 

spring-boot-agent/src/main/java/com/qianglu/agent/AgentStartup.java

@@ -2,6 +2,7 @@ package com.qianglu.agent;
 
 
 import com.qianglu.agent.service.DumpClassesService;
+import com.qianglu.agent.service.PerformMonitorTransformer;
 
 import java.lang.instrument.Instrumentation;
 
@@ -13,5 +14,5 @@ public class AgentStartup {
 	public static void premain(String arg, Instrumentation instrumentation) {
 		System.err.println("agent startup , args is " + arg);
 		// 注册我们的文件下载函数
-		instrumentation.addTransformer(new DumpClassesService());	}
+		instrumentation.addTransformer(new PerformMonitorTransformer());	}
 }

spring-boot-agent/src/main/java/com/qianglu/agent/service/PerformMonitorTransformer.java

+package com.qianglu.agent.service;
+
+import javassist.CannotCompileException;
+import javassist.ClassPool;
+import javassist.CtBehavior;
+import javassist.CtClass;
+import javassist.expr.ExprEditor;
+import javassist.expr.MethodCall;
+
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.IllegalClassFormatException;
+import java.security.ProtectionDomain;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * 测试
+ *
+ * @author QIANGLU on 2019-09-02
+ */
+public class PerformMonitorTransformer implements ClassFileTransformer {
+    private static final Set<String> classNameSet = new HashSet<>();
+    static {
+        classNameSet.add("com.example.demo.AgentTest");
+    }
+
+    @Override
+    public byte[] transform(ClassLoader loader,
+                            String className,
+                            Class<?> classBeingRedefined,
+                            ProtectionDomain protectionDomain,
+                            byte[] classfileBuffer) throws IllegalClassFormatException {
+        try {
+            String currentClassName = className.replaceAll("/", ".");
+            if (!classNameSet.contains(currentClassName)) { // 仅仅提升Set中含有的类
+                return null;
+            }
+            System.out.println("transform: [" + currentClassName + "]");
+
+            CtClass ctClass = ClassPool.getDefault().get(currentClassName);
+            CtBehavior[] methods = ctClass.getDeclaredBehaviors();
+            for (CtBehavior method : methods) {
+                enhanceMethod(method);
+            }
+            return ctClass.toBytecode();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    private void enhanceMethod(CtBehavior method) throws Exception {
+        if (method.isEmpty()) {
+            return;
+        }
+        String methodName = method.getName();
+        if (methodName.equalsIgnoreCase("main")) { // 不提升main方法
+            return;
+        }
+
+        final StringBuilder source = new StringBuilder();
+        source.append("{")
+                .append("long start = System.nanoTime();\n") // 前置增强: 打入时间戳
+                .append("$_ = $proceed($$);\n") // 保留原有的代码处理逻辑
+                .append("System.out.print(\"method:[" + methodName + "]\");").append("\n")
+                .append("System.out.println(\" cost:[\" +(System.nanoTime() -start)+ \"ns]\");") // 后置增强
+                .append("}");
+
+        ExprEditor editor = new ExprEditor() {
+            @Override
+            public void edit(MethodCall methodCall) throws CannotCompileException {
+                methodCall.replace(source.toString());
+            }
+        };
+        method.instrument(editor);
+    }
+}
\ No newline at end of file