动态查询java代码运行细节
Btrace:在不修改现有代码、不重新启动应用服务器的前提下，观察程序的现有运行状态。
以下是测试时间。
1、先jps一下服务器的pid
2、btrace pid 下面的java代码的文件名
Btrace在Linux\Windows上都能运行。
package net.bwda.ssim;import static com.sun.btrace.BTraceUtils.*;import com.sun.btrace.annotations.BTrace;import com.sun.btrace.annotations.Kind;import com.sun.btrace.annotations.Location;import com.sun.btrace.annotations.OnMethod;import com.sun.btrace.annotations.TLS;@BTracepublic class TestBtrace {@TLSstatic long beginTime;@OnMethod(clazz = "net.bwda.ssim.web.charts.VirusAreaAction", method = "updateDataXml")public static void begin() {beginTime = timeMillis();}@OnMethod(clazz = "net.bwda.ssim.web.charts.VirusAreaAction", method = "updateDataXml", location = @Location(Kind.RETURN))public static void traceMethod() {println(strcat(strcat("updateDataXml time is:", str(timeMillis() - beginTime)), "ms"));}}