ThreadLocal实现线程级上下文

一.ThreadLocal测试

 1 package com.junge.threadlocal.context;
 2 
 3 /**
 4  * @author Administrator
 5  * 
 6  */
 7 public class ThreadScopeData {
 8     private ThreadScopeData() {
 9 
10     }
11 
12     private static ThreadLocal<ThreadScopeData> threadLocal = new ThreadLocal<ThreadScopeData>();
13 
14     public static ThreadScopeData getInstance() {
15         if (null == threadLocal.get()) {
16             threadLocal.set(new ThreadScopeData());
17         }
18 
19         return threadLocal.get();
20     }
21 
22     public static void main(String[] args) {
23 
24         new Thread(new Runnable() {
25             @Override
26             public void run() {
27                 System.out.println(ThreadScopeData.getInstance());
28 
29             }
30         }).start();
31 
32         new Thread(new Runnable() {
33             @Override
34             public void run() {
35                 System.out.println(ThreadScopeData.getInstance());
36 
37             }
38         }).start();
39     }
40 }

二.对上下接口进行封装，使用方便（线程绑定不同的业务数据，线程之间的业务数据放在上下文中）

1.上下文接口ThreadContext

package com.junge.threadlocal.context;

import java.util.Map;

/**
 * 线程上下文接口
 * 
 * @author Administrator
 * 
 */
public interface ThreadContext {

    /**
     * 保持用户名
     * 
     * @param userName
     */
    void setUserName(String userName);

    /**
     * 获取用户名
     * 
     * @return
     */
    String getUserName();

    /**
     * 保持参数1
     * 
     * @param param
     */
    void setParam1(Object param);

    /**
     * 获取参数1
     * 
     * @return
     */
    Object getParam1();

    /**
     * 添加参数
     * 
     * @param key
     * @param param
     */
    void addParam(String key, Object param);

    /**
     * 获取参数
     * 
     * @param key
     * @return
     */
    Object getParam(String key);

    /**
     * 获取所有添加的参数
     * 
     * @return
     */
    Map<String, Object> getAllParam();
}

2.线程上下文接口实现ThreadContextImpl

package com.junge.threadlocal.context;

import java.util.HashMap;
import java.util.Map;

/**
 * 线程上下文接口实现
 * 
 * @author Administrator
 * 
 */
public class ThreadContextImpl implements ThreadContext {

    private String userName;

    private Object param1;

    private Map<String, Object> paramMap;

    @Override
    public void setUserName(String userName) {
        this.userName = userName;

    }

    @Override
    public String getUserName() {

        return this.userName;
    }

    @Override
    public void setParam1(Object param) {
        this.param1 = param;

    }

    @Override
    public Object getParam1() {

        return param1;
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.junge.threadlocal.context.ThreadContext#addParam(java.lang.String,
     * java.lang.Object)
     */
    @Override
    public void addParam(String key, Object param) {
        if (null == paramMap) {
            paramMap = new HashMap<String, Object>();
        }

        paramMap.put(key, param);

    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.junge.threadlocal.context.ThreadContext#getParam(java.lang.String)
     */
    @Override
    public Object getParam(String key) {
        if (null == paramMap) {
            paramMap = new HashMap<String, Object>();
        }
        return paramMap.get(key);
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.junge.threadlocal.context.ThreadContext#getAllParam()
     */
    @Override
    public Map<String, Object> getAllParam() {
        if (null == paramMap) {
            paramMap = new HashMap<String, Object>();
        }
        return paramMap;
    }

}

3.线程上下文助手ThreadContextHolder

 1 /**
 2  * 
 3  */
 4 package com.junge.threadlocal.context;
 5 
 6 import java.util.Map;
 7 
 8 /**
 9  * 线程上下文助手
10  * 
11  * @author Administrator
12  * 
13  */
14 public class ThreadContextHolder {
15 
16     /**
17      * 上下文保持对象
18      */
19     private static ThreadLocal<ThreadContext> threadContext = new ThreadLocal<ThreadContext>();
20 
21     public static void setThreadContext(ThreadContext context) {
22         threadContext.set(context);
23     }
24 
25     public static ThreadContext getThreadContext() {
26         if (null == threadContext.get()) {
27             threadContext.set(new ThreadContextImpl());
28         }
29         return threadContext.get();
30     }
31 
32     public static void setUserName(String userName) {
33         getThreadContext().setUserName(userName);
34     }
35 
36     public static String getUserName() {
37         return getThreadContext().getUserName();
38     }
39 
40     public static void setParam1(Object param) {
41         getThreadContext().setParam1(param);
42     }
43 
44     public static Object getParam1() {
45         return getThreadContext().getParam1();
46     }
47 
48     public static void addParam(String key, Object param) {
49         getThreadContext().addParam(key, param);
50     }
51 
52     public static Object getParam(String key) {
53         return getThreadContext().getParam(key);
54     }
55 
56     public static Map<String, Object> getAllParam() {
57         return getThreadContext().getAllParam();
58     }
59 
60 }

4.线程上下文测试代码

 1 package com.junge.threadlocal.context;
 2 
 3 public class ThreadContextHolderTest {
 4 
 5     /**
 6      * @param args
 7      */
 8     public static void main(String[] args) {
 9         new Thread(new Runnable() {
10             @Override
11             public void run() {
12                 ThreadContextHolder.setUserName("userName1");
13                 ThreadContextHolder.setParam1(new Object());
14                 ThreadContextHolder.addParam("param1", "aaaa");
15 
16                 System.out.println(Thread.currentThread().getName() + ":"
17                         + ThreadContextHolder.getUserName());
18                 System.out.println(Thread.currentThread().getName() + ":"
19                         + ThreadContextHolder.getParam1());
20                 System.out.println(Thread.currentThread().getName() + ":"
21                         + ThreadContextHolder.getParam("param1"));
22 
23             }
24         }).start();
25 
26         new Thread(new Runnable() {
27             @Override
28             public void run() {
29                 ThreadContextHolder.setUserName("userName2");
30                 ThreadContextHolder.setParam1(new Object());
31                 ThreadContextHolder.addParam("param1", "bbbb");
32 
33                 System.out.println(Thread.currentThread().getName() + ":"
34                         + ThreadContextHolder.getUserName());
35                 System.out.println(Thread.currentThread().getName() + ":"
36                         + ThreadContextHolder.getParam1());
37                 System.out.println(Thread.currentThread().getName() + ":"
38                         + ThreadContextHolder.getParam("param1"));
39 
40             }
41         }).start();
42 
43     }
44 
45 }
运行结果：
Thread-0:userName1
Thread-0:java.lang.Object@6e1408
Thread-0:aaaa
Thread-1:userName2
Thread-1:java.lang.Object@e53108
Thread-1:bbbb