threadLoccal 里面有什么?

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老外的:

package util;

import java.lang.ref.Reference;
import java.lang.reflect.Field;
import java.util.Arrays;

public class ThreadLocalUtil {
	 public static  void dumphreadLocals() {
	        try {
	            // Get a reference to the thread locals table of the current thread
	            Thread thread = Thread.currentThread();
	            Field threadLocalsField = Thread.class.getDeclaredField("threadLocals");
	            threadLocalsField.setAccessible(true);
	            Object threadLocalTable = threadLocalsField.get(thread);

	            // Get a reference to the array holding the thread local variables inside the
	            // ThreadLocalMap of the current thread
	            @SuppressWarnings("rawtypes")
				Class threadLocalMapClass = Class.forName("java.lang.ThreadLocal$ThreadLocalMap");
	            Field tableField = threadLocalMapClass.getDeclaredField("table");
	            tableField.setAccessible(true);
	            Object[] table = (Object[]) tableField.get(threadLocalTable);

	            @SuppressWarnings("rawtypes")
				Class threadLocalMapEntryClass = Class.forName("java.lang.ThreadLocal$ThreadLocalMap$Entry");
	            Field entryValueField = threadLocalMapEntryClass.getDeclaredField("value");
	            entryValueField.setAccessible(true);
	            // The key to the ThreadLocalMap is a WeakReference object. The referent field of this object
	            // is a reference to the actual ThreadLocal variable
	            Field referentField = Reference.class.getDeclaredField("referent");
	            referentField.setAccessible(true);

	            for (Object entry:table) {
	                // Each entry in the table array of ThreadLocalMap is an Entry object
	                // representing the thread local reference and its value
	                if (entry != null) {
	                	Object tlcValue=entryValueField.get(entry);
	                    //ThreadLocal threadLocal = (ThreadLocal)referentField.get(entry);
	                    //System.out.println("thread local  value "+tlcValue);
	                    printObject(tlcValue);
	                }
	            }
	        } catch(Exception e) {
	            // We will tolerate an exception here and just log it
	            throw new IllegalStateException(e);
	        }
	    }
	
	 @SuppressWarnings("rawtypes")
	private static void printObject(Object obj)
	 {
		 System.out.print("find threadlocal var :");
		 if(obj instanceof Object[])
		 {
			 System.out.println(Arrays.deepToString((Object[]) obj));
		 }else if (obj instanceof java.lang.ref.Reference)
		 {
			 java.lang.ref.Reference ref=(Reference) obj;
			 System.out.println(" ref "+ref.getClass().getName()+" ref to "+ref.get());
		 }else
		 {
			 System.out.println(obj);
		 }
	 }
	public static void main(String[] args) throws NoSuchMethodException, SecurityException
	{
		
		dumphreadLocals();
	}
}

偶自己的:

import java.lang.reflect.Field;
import java.lang.reflect.Method;
//import java.lang.StringCoding;


public class testThreadLoacal {

	/**
	 * @param args
	 * @throws SecurityException 
	 * @throws NoSuchFieldException 
	 */
	public static void main(String[] args) throws Exception {
		Thread t = Thread.currentThread();
		//获取threadLocals对象
		Object threadLocals = getField(t,"threadLocals");		
		//获取table对象啊
		Object table = getField(threadLocals, "table");
		Object[] tableArray = null;
		if(table.getClass().isArray()) {
			//数组强转
			tableArray = (Object[])table;
			//转换为数组,迭代entry
			for(int i = 0 ; i < tableArray.length ; i++) {
				//System.out.println(tableArray[i]);				
				if(null != tableArray[i] ) {
					//打印value
					Object value = getField(tableArray[i],"value");
					System.out.println("====================");
					printFiledNames(value);			
					System.out.println("====================");

					System.out.println(value);
					if(value != null){
						//获取refer的链接对象,可以不用反射了,直接强转为Reference
						Method getMethod = value.getClass().getMethod("get");
						Object softReference = getMethod.invoke(value);
						System.out.println(softReference);
						for(Method method : softReference.getClass().getDeclaredMethods()){
							System.out.println(method.getName());
						}
						// System.out.println(getField(value,"referent"));;
					}
				}
				
			}
		}
		
		//Field[] fields = threadLocalsClazz.getDeclaredFields();
		System.out.println(table);
	}
	public static Object getField(Object instance ,String fieldName) throws Exception {
		Class threadLocalsClazz = instance.getClass();
		Field tableField = threadLocalsClazz.getDeclaredField(fieldName);
		tableField.setAccessible(true);
		Object table = tableField.get(instance);
		return table;
	}
	
	public static void printFiledNames(Object object) {
		Field[] fields = object.getClass().getFields();
		
		for(int i = 0 ; i < fields.length;i++) {
			System.out.println(fields[i].getName());
		}
	}
	

	
	
	
}