import com.google.common.base.Stopwatch; import java.util.concurrent.TimeUnit; publicclassStackTest{ publicstaticvoidmain(String[] args){ Stopwatch started = new Stopwatch(); started.start(); User user = null; for (long i = 0; i < 1000_000_000; i++) { user = new User(); } started.stop(); System.out.println(started.elapsed(TimeUnit.MILLISECONDS) + "ms"); //不加打印 300ms //加了打印 3000ms // System.out.println(user); } }
"main" #1 prio=5 os_prio=0 tid=0x00007f943004c800 nid=0x1079 runnable [0x00007f9439fe0000] java.lang.Thread.State: RUNNABLE at java.util.regex.Pattern$Curly.match0(Pattern.java:4264) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) // at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4195) at java.util.regex.Pattern$Curly.match0(Pattern.java:4293) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4195) at java.util.regex.Pattern$Curly.match0(Pattern.java:4293) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4195) at java.util.regex.Pattern$Curly.match0(Pattern.java:4293) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.match(Pattern.java:4799) at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731) at java.util.regex.Pattern$Ques.match(Pattern.java:4196) at java.util.regex.Pattern$Curly.match0(Pattern.java:4286) at java.util.regex.Pattern$Curly.match(Pattern.java:4248) at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672) at java.util.regex.Pattern$Loop.matchInit(Pattern.java:4815) at java.util.regex.Pattern$Prolog.match(Pattern.java:4755) at java.util.regex.Pattern$Begin.match(Pattern.java:3539) at java.util.regex.Matcher.search(Matcher.java:1248) at java.util.regex.Matcher.find(Matcher.java:637) at org.rz.search.spider.AppMain.main(AppMain.java:13)
publicclassAddMain{ publicstaticvoidmain(String[] args){ int c = add(100,200); System.out.println(c); } privatestaticintadd(int a, int b){ return a + b; } }
这个例子中的 java 代码,add 方法对应的代码是 (II)I,最后一个 I 代表返回值,这个代表两个整型的参数.
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privatestaticintadd(int a, int b,String c,boolean d){ return a + b; }