这里学习Thread的两个比较简单的API，直接上代码：
线程ID：
那它的生成规则是？直接看源码：
那为什么目前打印是9呢？然后在jvm启动的时候就已经创建了8个线程？继续用jconsole来验证一下：
启动jconsole:
优先级：
我们在学习java线程中都知道这个优先级在实际中是不受控的，也就是说要控制线程的优先级不能通过它的API来，而应该是从咱们的逻辑上去实现，但是这里还是做一个了解，试一下它的效果:
编译运行：
Thread-0-index0 Thread-0-index1 Thread-0-index2 Thread-0-index3 Thread-0-index4 Thread-0-index5 Thread-0-index6 Thread-0-index7 Thread-0-index8 Thread-0-index9 Thread-1-index0 Thread-1-index1 Thread-1-index2 Thread-0-index10 Thread-1-index3 Thread-1-index4 Thread-1-index5 Thread-1-index6 Thread-0-index11 Thread-2-index0 Thread-2-index1 Thread-2-index2 Thread-2-index3 Thread-1-index7 Thread-1-index8 Thread-1-index9 Thread-2-index4 Thread-2-index5 Thread-2-index6 Thread-0-index12 Thread-0-index13 Thread-0-index14 Thread-2-index7 Thread-1-index10 Thread-1-index11 Thread-1-index12 Thread-1-index13 Thread-1-index14 Thread-1-index15 Thread-1-index16 Thread-2-index8 Thread-2-index9 Thread-0-index15 Thread-2-index10 Thread-2-index11 Thread-2-index12 Thread-2-index13 Thread-2-index14 Thread-2-index15 Thread-2-index16 Thread-2-index17 Thread-2-index18 Thread-2-index19 Thread-2-index20 Thread-2-index21 Thread-2-index22 Thread-2-index23 Thread-2-index24 Thread-1-index17 Thread-2-index25 Thread-0-index16 Thread-2-index26 Thread-1-index18 Thread-2-index27 Thread-0-index17 Thread-2-index28 Thread-2-index29 Thread-2-index30 Thread-2-index31 Thread-2-index32 Thread-2-index33 Thread-2-index34 Thread-2-index35 Thread-2-index36 Thread-2-index37 Thread-1-index19 Thread-2-index38 Thread-2-index39 Thread-2-index40 Thread-2-index41 Thread-2-index42 Thread-2-index43 Thread-2-index44 Thread-0-index18 Thread-2-index45 Thread-2-index46 Thread-1-index20 Thread-1-index21 Thread-2-index47 Thread-0-index19 Thread-2-index48 Thread-1-index22 Thread-2-index49 Thread-2-index50 Thread-2-index51 Thread-2-index52 Thread-0-index20 Thread-2-index53 Thread-1-index23 Thread-1-index24 Thread-2-index54 Thread-0-index21 Thread-2-index55 Thread-2-index56 Thread-1-index25 Thread-2-index57 Thread-2-index58 Thread-2-index59 Thread-2-index60 Thread-2-index61 Thread-2-index62 Thread-2-index63 Thread-2-index64 Thread-2-index65 Thread-2-index66 Thread-2-index67 Thread-2-index68 Thread-0-index22 Thread-0-index23 Thread-0-index24 Thread-0-index25 Thread-2-index69 Thread-1-index26 Thread-1-index27 Thread-1-index28 Thread-2-index70 Thread-2-index71 Thread-2-index72 Thread-0-index26 Thread-2-index73 Thread-1-index29 Thread-1-index30 Thread-1-index31 Thread-1-index32 Thread-1-index33 Thread-1-index34 Thread-2-index74 Thread-0-index27 Thread-0-index28 Thread-0-index29 Thread-2-index75 Thread-1-index35 Thread-2-index76 Thread-0-index30 Thread-0-index31 Thread-0-index32 Thread-2-index77 Thread-2-index78 Thread-2-index79 Thread-2-index80 Thread-2-index81 Thread-2-index82 Thread-2-index83 Thread-2-index84 Thread-2-index85 Thread-1-index36 Thread-2-index86 Thread-0-index33 Thread-0-index34 Thread-0-index35 Thread-0-index36 Thread-0-index37 Thread-0-index38 Thread-0-index39 Thread-0-index40 Thread-0-index41 Thread-0-index42 Thread-0-index43 Thread-0-index44 Thread-0-index45 Thread-2-index87 Thread-1-index37 Thread-1-index38 Thread-2-index88 Thread-0-index46 Thread-0-index47 Thread-0-index48 Thread-0-index49 Thread-0-index50 Thread-0-index51 Thread-0-index52 Thread-0-index53 Thread-0-index54 Thread-2-index89 Thread-1-index39 Thread-1-index40 Thread-1-index41 Thread-1-index42 Thread-1-index43 Thread-2-index90 Thread-2-index91 Thread-2-index92 Thread-0-index55 Thread-2-index93 Thread-2-index94 Thread-1-index44 Thread-2-index95 Thread-2-index96 Thread-2-index97 Thread-2-index98 Thread-2-index99 Thread-0-index56 Thread-1-index45 Thread-1-index46 Thread-1-index47 Thread-1-index48 Thread-1-index49 Thread-1-index50 Thread-1-index51 Thread-1-index52 Thread-1-index53 Thread-1-index54 Thread-1-index55 Thread-1-index56 Thread-1-index57 Thread-1-index58 Thread-1-index59 Thread-0-index57 Thread-1-index60 Thread-1-index61 Thread-1-index62 Thread-1-index63 Thread-1-index64 Thread-1-index65 Thread-1-index66 Thread-1-index67 Thread-1-index68 Thread-1-index69 Thread-1-index70 Thread-1-index71 Thread-1-index72 Thread-1-index73 Thread-1-index74 Thread-1-index75 Thread-1-index76 Thread-1-index77 Thread-1-index78 Thread-1-index79 Thread-1-index80 Thread-1-index81 Thread-1-index82 Thread-1-index83 Thread-1-index84 Thread-1-index85 Thread-1-index86 Thread-1-index87 Thread-1-index88 Thread-1-index89 Thread-1-index90 Thread-0-index58 Thread-1-index91 Thread-0-index59 Thread-0-index60 Thread-1-index92 Thread-0-index61 Thread-0-index62 Thread-0-index63 Thread-1-index93 Thread-0-index64 Thread-1-index94 Thread-0-index65 Thread-0-index66 Thread-0-index67 Thread-0-index68 Thread-0-index69 Thread-1-index95 Thread-0-index70 Thread-0-index71 Thread-0-index72 Thread-0-index73 Thread-0-index74 Thread-0-index75 Thread-1-index96 Thread-0-index76 Thread-0-index77 Thread-1-index97 Thread-0-index78 Thread-1-index98 Thread-1-index99 Thread-0-index79 Thread-0-index80 Thread-0-index81 Thread-0-index82 Thread-0-index83 Thread-0-index84 Thread-0-index85 Thread-0-index86 Thread-0-index87 Thread-0-index88 Thread-0-index89 Thread-0-index90 Thread-0-index91 Thread-0-index92 Thread-0-index93 Thread-0-index94 Thread-0-index95 Thread-0-index96 Thread-0-index97 Thread-0-index98 Thread-0-index99
当然每次执行可能不一样，这时设置一下各线程中的优先级：
编译运行：
Thread-0-index0 Thread-0-index1 Thread-0-index2 Thread-0-index3 Thread-0-index4 Thread-0-index5 Thread-0-index6 Thread-0-index7 Thread-0-index8 Thread-0-index9 Thread-0-index10 Thread-0-index11 Thread-0-index12 Thread-0-index13 Thread-0-index14 Thread-0-index15 Thread-0-index16 Thread-0-index17 Thread-0-index18 Thread-0-index19 Thread-0-index20 Thread-0-index21 Thread-0-index22 Thread-0-index23 Thread-0-index24 Thread-0-index25 Thread-0-index26 Thread-0-index27 Thread-0-index28 Thread-0-index29 Thread-0-index30 Thread-0-index31 Thread-1-index0 Thread-1-index1 Thread-0-index32 Thread-1-index2 Thread-1-index3 Thread-1-index4 Thread-0-index33 Thread-1-index5 Thread-0-index34 Thread-1-index6 Thread-1-index7 Thread-1-index8 Thread-1-index9 Thread-0-index35 Thread-1-index10 Thread-2-index0 Thread-2-index1 Thread-1-index11 Thread-0-index36 Thread-0-index37 Thread-0-index38 Thread-0-index39 Thread-1-index12 Thread-1-index13 Thread-1-index14 Thread-2-index2 Thread-1-index15 Thread-1-index16 Thread-1-index17 Thread-1-index18 Thread-1-index19 Thread-1-index20 Thread-0-index40 Thread-1-index21 Thread-2-index3 Thread-1-index22 Thread-0-index41 Thread-1-index23 Thread-2-index4 Thread-1-index24 Thread-1-index25 Thread-1-index26 Thread-1-index27 Thread-0-index42 Thread-1-index28 Thread-2-index5 Thread-2-index6 Thread-1-index29 Thread-1-index30 Thread-0-index43 Thread-0-index44 Thread-0-index45 Thread-0-index46 Thread-0-index47 Thread-1-index31 Thread-2-index7 Thread-2-index8 Thread-1-index32 Thread-0-index48 Thread-1-index33 Thread-2-index9 Thread-1-index34 Thread-0-index49 Thread-1-index35 Thread-1-index36 Thread-1-index37 Thread-1-index38 Thread-1-index39 Thread-1-index40 Thread-1-index41 Thread-1-index42 Thread-1-index43 Thread-1-index44 Thread-1-index45 Thread-1-index46 Thread-1-index47 Thread-1-index48 Thread-1-index49 Thread-1-index50 Thread-1-index51 Thread-1-index52 Thread-1-index53 Thread-1-index54 Thread-1-index55 Thread-1-index56 Thread-1-index57 Thread-1-index58 Thread-1-index59 Thread-1-index60 Thread-1-index61 Thread-1-index62 Thread-1-index63 Thread-1-index64 Thread-1-index65 Thread-1-index66 Thread-1-index67 Thread-1-index68 Thread-1-index69 Thread-1-index70 Thread-1-index71 Thread-1-index72 Thread-1-index73 Thread-1-index74 Thread-1-index75 Thread-1-index76 Thread-1-index77 Thread-1-index78 Thread-1-index79 Thread-1-index80 Thread-1-index81 Thread-1-index82 Thread-1-index83 Thread-1-index84 Thread-1-index85 Thread-1-index86 Thread-1-index87 Thread-1-index88 Thread-1-index89 Thread-1-index90 Thread-1-index91 Thread-1-index92 Thread-1-index93 Thread-1-index94 Thread-1-index95 Thread-1-index96 Thread-1-index97 Thread-1-index98 Thread-1-index99 Thread-2-index10 Thread-0-index50 Thread-2-index11 Thread-0-index51 Thread-2-index12 Thread-0-index52 Thread-2-index13 Thread-2-index14 Thread-2-index15 Thread-0-index53 Thread-2-index16 Thread-0-index54 Thread-0-index55 Thread-0-index56 Thread-0-index57 Thread-0-index58 Thread-2-index17 Thread-0-index59 Thread-0-index60 Thread-2-index18 Thread-0-index61 Thread-2-index19 Thread-0-index62 Thread-2-index20 Thread-0-index63 Thread-2-index21 Thread-0-index64 Thread-2-index22 Thread-0-index65 Thread-0-index66 Thread-0-index67 Thread-0-index68 Thread-0-index69 Thread-0-index70 Thread-0-index71 Thread-0-index72 Thread-0-index73 Thread-0-index74 Thread-0-index75 Thread-0-index76 Thread-0-index77 Thread-0-index78 Thread-0-index79 Thread-0-index80 Thread-0-index81 Thread-0-index82 Thread-0-index83 Thread-0-index84 Thread-0-index85 Thread-0-index86 Thread-0-index87 Thread-0-index88 Thread-0-index89 Thread-0-index90 Thread-0-index91 Thread-0-index92 Thread-0-index93 Thread-0-index94 Thread-0-index95 Thread-0-index96 Thread-0-index97 Thread-0-index98 Thread-0-index99 Thread-2-index23 Thread-2-index24 Thread-2-index25 Thread-2-index26 Thread-2-index27 Thread-2-index28 Thread-2-index29 Thread-2-index30 Thread-2-index31 Thread-2-index32 Thread-2-index33 Thread-2-index34 Thread-2-index35 Thread-2-index36 Thread-2-index37 Thread-2-index38 Thread-2-index39 Thread-2-index40 Thread-2-index41 Thread-2-index42 Thread-2-index43 Thread-2-index44 Thread-2-index45 Thread-2-index46 Thread-2-index47 Thread-2-index48 Thread-2-index49 Thread-2-index50 Thread-2-index51 Thread-2-index52 Thread-2-index53 Thread-2-index54 Thread-2-index55 Thread-2-index56 Thread-2-index57 Thread-2-index58 Thread-2-index59 Thread-2-index60 Thread-2-index61 Thread-2-index62 Thread-2-index63 Thread-2-index64 Thread-2-index65 Thread-2-index66 Thread-2-index67 Thread-2-index68 Thread-2-index69 Thread-2-index70 Thread-2-index71 Thread-2-index72 Thread-2-index73 Thread-2-index74 Thread-2-index75 Thread-2-index76 Thread-2-index77 Thread-2-index78 Thread-2-index79 Thread-2-index80 Thread-2-index81 Thread-2-index82 Thread-2-index83 Thread-2-index84 Thread-2-index85 Thread-2-index86 Thread-2-index87 Thread-2-index88 Thread-2-index89 Thread-2-index90 Thread-2-index91 Thread-2-index92 Thread-2-index93 Thread-2-index94 Thread-2-index95 Thread-2-index96 Thread-2-index97 Thread-2-index98 Thread-2-index99
从结果中确实有一些影响，第一个线程先执行了，第二个次之，第三个最后执行，但是基本也是交替进行的，所以这里纯学习试验，实际基本上不会用这个API，了解下。