java多线程问题

Question

有2个文件，a.txt，b.txt，分别有10行内容，现要求一行一行读取a.txt，b.txt。将读取的内容按顺序写到到c.txt文件中。
比如a.txt内容为：
1
3
5
7
9
b.txt内容为：
2
4
6
8
输入到c.txt的内容为：
1
2
3
4
5
6
7
8
9求如何编写

Answer 1

这根本不是多线程问题，用两个list记录内容，合并排序

Answer 2

可以考虑用公平锁的方式来处理.
当然也可以考虑通过定义一个标志flag来让一个线程wait,并触发另一个线程运行的方式来处理上面的这个问题.
一下是用公平锁的方式import java.util.concurrent.locks.ReentrantLock;public class Test{

public static void main(String[] args){
ReentrantLock lock = new ReentrantLock(true);
String[] strs1 = {"1","3","5","7","9"};
String[] strs2 = {"2","4","6","8","10"};
Thread thread1 = getThread(strs1,lock);
Thread thread2 = getThread(strs2,lock);
thread1.start();
try{
Thread.sleep(10);
}catch(Exception e){
e.printStackTrace();
}
thread2.start();
}
public static Thread getThread(String[] strs,ReentrantLock lock){
Thread thread = new Thread(){
@Override
public void run(){
for(int i = 0 ; i < strs.length ; i ++){
lock.lock();
System.out.println(strs[i]);
lock.unlock();
try{
Thread.sleep(20);
}catch(Exception e){
e.printStackTrace();
}
}
}
}; return thread;
}
}

Answer 3

    public final String FILE_END="FILE_END";    @Test
    public void test() throws IOException {
        FileReader f1 = new FileReader(FileTest.class.getResource("a.txt").getFile());
        FileReader f2 = new FileReader(FileTest.class.getResource("b.txt").getFile());
        final FileWriter f3 = new FileWriter(FileTest.class.getResource("c.txt").getFile());
        final LinkedBlockingDeque<String> q1=new LinkedBlockingDeque<String>();
        final LinkedBlockingDeque<String> q2=new LinkedBlockingDeque<String>();
        System.out.println(FileTest.class.getResource("c.txt").getFile());
        getReadThread(f1,q1,"t--1").start();
        getReadThread(f2,q2,"t--2").start();
        getWriteThread(f3,q1,q2,"t--3").start();
        while (Thread.activeCount()>2){
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    public Thread getWriteThread(final FileWriter f, final LinkedBlockingDeque<String> q1,final  LinkedBlockingDeque<String> q2,String name){
        return new Thread(new Runnable() {
            BufferedWriter bw=new BufferedWriter(f);
            @Override
            public void run() {
                try {
                    boolean go1=true;
                    boolean go2=true;
                    while (go1||go2) {
                        if(go1){
                            String c1=q1.take();
                            if(c1==FILE_END){
                                go1=false;
                            }else {
                                bw.write(c1);
                                bw.newLine();
                            }
                        }
                        if(go2){
                            String c2=q2.take();
                            if(c2==FILE_END){
                                go2=false;
                            }else {
                                bw.write(c2);
                                bw.newLine();
                            }
                        }
                    }
                    System.out.println("=======***********======");
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    try {
                        bw.close();
                        f.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        },name);
    }
    public Thread getReadThread(final FileReader f, final LinkedBlockingDeque<String> q,String name){
        return new Thread(new Runnable() {
            @Override
            public void run() {
                BufferedReader bufferedReader=new BufferedReader(f);
                String line=null;
                try {
                    while ((line=bufferedReader.readLine())!=null){
                        q.add(line);
                    }
                    q.add(FILE_END);
                } catch (IOException e) {
                    e.printStackTrace();
                }finally {
                    try {
                        bufferedReader.close();
                        f.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        },name);
    }