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@aloxc 2017-12-05T06:22:33.000000Z 字数 6849 阅读 478

我们一起学ignite之MXBean

一起学 ignite 源码分析

如题，ignite中定义了若干个MXBean及几个和MxBean相关的annotation，这些代码共同构成ignite中jmx想相关功能。
话不多说，直接看代码吧，

  1. @Documented
  2. @Retention(RetentionPolicy.RUNTIME)
  3. @Target({ElementType.TYPE, ElementType.METHOD})
  4. public @interface MXBeanDescription {
  5.     public String value();
  6. }
  2. @Documented
  3. @Retention(RetentionPolicy.RUNTIME)
  4. @Target({ElementType.METHOD})
  5. public @interface MXBeanParametersDescriptions {
  6.     public String[] value();
  7. }
  1. @Documented
  2. @Retention(RetentionPolicy.RUNTIME)
  3. @Target({ElementType.METHOD})
  4. public @interface MXBeanParametersNames {
  5.     public String[] value();
  6. }

这三个注解很简单，一个负责注解MXBean接口定义类和接口中的方法，一个负责注解接口中方法的参数列表，一个负责注解参数的描述。
随便找一个MXBean看一下，比如IgniteMXBean，下面代码节选了一部分

  1. @MXBeanDescription("MBean that provides access to Kernal information.")
  2. public interface IgniteMXBean {
  4.     @MXBeanDescription("String presentation of the Ignite version.")
  5.     public String getFullVersion();
  8.     @MXBeanDescription("A shortcut method that executes given task assuming single " +
  9.         "String argument and String return type. Returns Task return value (assumed of String type).")
  10.     @MXBeanParametersNames(
  11.         {
  12.             "taskName",
  13.             "arg"
  14.         }
  15.     )
  16.     @MXBeanParametersDescriptions(
  17.         {
  18.             "Name of the task to execute.",
  19.             "Single task execution argument (can be null)."
  20.         }
  21.     )
  22.     public String executeTask(String taskName, String arg) throws JMException;
  24. }

从代码中看到，接口类及接口中方法加了一些注解，这些注解的内容用于jmx相关功能，并使用IgniteStandardMXBean扩展java中StandardMXBean，如下IgniteStandardMXBean代码：

  2. package org.apache.ignite.internal.mxbean;
  4. import java.lang.reflect.Method;
  5. import java.util.HashMap;
  6. import java.util.Map;
  7. import javax.management.MBeanAttributeInfo;
  8. import javax.management.MBeanInfo;
  9. import javax.management.MBeanOperationInfo;
  10. import javax.management.MBeanParameterInfo;
  11. import javax.management.NotCompliantMBeanException;
  12. import javax.management.StandardMBean;
  13. import org.apache.ignite.internal.util.typedef.internal.U;
  14. import org.apache.ignite.mxbean.MXBeanDescription;
  15. import org.apache.ignite.mxbean.MXBeanParametersDescriptions;
  16. import org.apache.ignite.mxbean.MXBeanParametersNames;
  18. /**
  19.  * Extension of standard Java MBean. Overrides some hooks to return
  20.  * annotation based descriptions.
  21.  */
  22. public class IgniteStandardMXBean extends StandardMBean {
  24.     private static final Map<String, Class<?>> primCls = new HashMap<>();
  27.     static{
  28.         primCls.put(Boolean.TYPE.toString().toLowerCase(), Boolean.TYPE);
  29.         primCls.put(Character.TYPE.toString().toLowerCase(), Character.TYPE);
  30.         primCls.put(Byte.TYPE.toString().toLowerCase(), Byte.TYPE);
  31.         primCls.put(Short.TYPE.toString().toLowerCase(), Short.TYPE);
  32.         primCls.put(Integer.TYPE.toString().toLowerCase(), Integer.TYPE);
  33.         primCls.put(Long.TYPE.toString().toLowerCase(), Long.TYPE);
  34.         primCls.put(Float.TYPE.toString().toLowerCase(), Float.TYPE);
  35.         primCls.put(Double.TYPE.toString().toLowerCase(), Double.TYPE);
  36.     }
  39.     public <T> IgniteStandardMXBean(T implementation, Class<T> mbeanInterface)
  40.         throws NotCompliantMBeanException {
  41.         super(implementation, mbeanInterface);
  42.     }
  45.     @Override protected String getDescription(MBeanAttributeInfo info) {
  46.         String str = super.getDescription(info);
  48.         String methodName = (info.isIs() ? "is" : "get") + info.getName();
  50.         try {
  51.             // Recursively get method.
  52.             Method mtd = findMethod(getMBeanInterface(), methodName, new Class[]{});
  54.             if (mtd != null) {
  55.                 MXBeanDescription desc = mtd.getAnnotation(MXBeanDescription.class);
  57.                 if (desc != null) {
  58.                     str = desc.value();
  60.                     assert str != null : "Failed to find method: " + mtd;
  61.                     assert str.trim().length() > 0 : "Method description cannot be empty: " + mtd;
  63.                     // Enforce proper English.
  64.                     assert Character.isUpperCase(str.charAt(0)) == true :
  65.                         "Description must start with upper case: " + str;
  67.                     assert str.charAt(str.length() - 1) == '.' : "Description must end with period: " + str;
  68.                 }
  69.             }
  70.         }
  71.         catch (SecurityException e) {
  72.             // No-op. Default value will be returned.
  73.         }
  75.         return str;
  76.     }
  79.     @Override protected String getDescription(MBeanInfo info) {
  80.         String str = super.getDescription(info);
  81.         MXBeanDescription desc = U.getAnnotation(getMBeanInterface(), MXBeanDescription.class);
  83.         if (desc != null) {
  84.             str = desc.value();
  86.             assert str != null;
  87.             assert str.trim().length() > 0;
  89.             // Enforce proper English.
  90.             assert Character.isUpperCase(str.charAt(0)) == true : str;
  91.             assert str.charAt(str.length() - 1) == '.' : str;
  92.         }
  94.         return str;
  95.     }
  97.     @Override protected String getDescription(MBeanOperationInfo info) {
  98.         String str = super.getDescription(info);
  100.         try {
  101.             Method m = getMethod(info);
  103.             MXBeanDescription desc = m.getAnnotation(MXBeanDescription.class);
  105.             if (desc != null) {
  106.                 str = desc.value();
  108.                 assert str != null;
  109.                 assert str.trim().length() > 0;
  111.                 // Enforce proper English.
  112.                 assert Character.isUpperCase(str.charAt(0)) == true : str;
  113.                 assert str.charAt(str.length() - 1) == '.' : str;
  114.             }
  115.         }
  116.         catch (SecurityException | ClassNotFoundException e) {
  117.             // No-op. Default value will be returned.
  118.         }
  120.         return str;
  121.     }
  123.     @Override protected String getDescription(MBeanOperationInfo op, MBeanParameterInfo param, int seq) {
  124.         String str = super.getDescription(op, param, seq);
  126.         try {
  127.             Method m = getMethod(op);
  129.             MXBeanParametersDescriptions decsAnn = m.getAnnotation(MXBeanParametersDescriptions.class);
  131.             if (decsAnn != null) {
  132.                 assert decsAnn.value() != null;
  133.                 assert seq < decsAnn.value().length;
  135.                 str = decsAnn.value()[seq];
  137.                 assert str != null;
  138.                 assert str.trim().length() > 0;
  140.                 // Enforce proper English.
  141.                 assert Character.isUpperCase(str.charAt(0)) == true : str;
  142.                 assert str.charAt(str.length() - 1) == '.' : str;
  143.             }
  144.         }
  145.         catch (SecurityException | ClassNotFoundException e) {
  146.             // No-op. Default value will be returned.
  147.         }
  149.         return str;
  150.     }
  152.     @Override protected String getParameterName(MBeanOperationInfo op, MBeanParameterInfo param, int seq) {
  153.         String str = super.getParameterName(op, param, seq);
  155.         try {
  156.             Method m = getMethod(op);
  158.             MXBeanParametersNames namesAnn = m.getAnnotation(MXBeanParametersNames.class);
  160.             if (namesAnn != null) {
  161.                 assert namesAnn.value() != null;
  162.                 assert seq < namesAnn.value().length;
  164.                 str = namesAnn.value()[seq];
  166.                 assert str != null;
  167.                 assert str.trim().length() > 0;
  168.             }
  169.         }
  170.         catch (SecurityException | ClassNotFoundException e) {
  171.             // No-op. Default value will be returned.
  172.         }
  174.         return str;
  175.     }
  176.     private Method getMethod(MBeanOperationInfo op) throws ClassNotFoundException, SecurityException {
  177.         String methodName = op.getName();
  179.         MBeanParameterInfo[] signature = op.getSignature();
  181.         Class<?>[] params = new Class<?>[signature.length];
  183.         for (int i = 0; i < signature.length; i++) {
  184.             // Parameter type is either a primitive type or class. Try both.
  185.             Class<?> type = primCls.get(signature[i].getType().toLowerCase());
  187.             if (type == null)
  188.                 type = Class.forName(signature[i].getType());
  190.             params[i] = type;
  191.         }
  193.         return findMethod(getMBeanInterface(), methodName, params);
  194.     }
  196.     @SuppressWarnings("unchecked")
  197.     private Method findMethod(Class itf, String methodName, Class[] params) {
  198.         assert itf.isInterface() == true;
  200.         Method res = null;
  202.         // Try to get method from given interface.
  203.         try {
  204.             res = itf.getDeclaredMethod(methodName, params);
  206.             if (res != null)
  207.                 return res;
  208.         }
  209.         catch (NoSuchMethodException e) {
  210.             // No-op. Default value will be returned.
  211.         }
  213.         // Process recursively super interfaces.
  214.         Class[] superItfs = itf.getInterfaces();
  216.         for (Class superItf: superItfs) {
  217.             res = findMethod(superItf, methodName, params);
  219.             if (res != null)
  220.                 return res;
  221.         }
  223.         return res;
  224.     }
  225. }

有了上面这些后，怎么使用呢，直接注册mxbean就可以了，如下代码

  1. Hello bean = new Hello("aloxcbbbb",34,"tret@gmail.com");
  2.         bean.addBook(new Book("abook",34.0));
  3.         MBeanServer server = ManagementFactory.getPlatformMBeanServer();
  4.         StandardMBean standardMBean = new StandardMBean(bean,HelloMXBean.class);
  5.         MBeanInfo info = standardMBean.getMBeanInfo();
  6.         server.registerMBean(standardMBean,new ObjectName("com.github.aloxc.mbean:type=Hello"));

接下来可以jconsole来连接ignite的jmx端口查看下有些什么东西~自己去验证看看有些什么，，，，

x

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