多线程同步查找包含特定内容的文件

import java.io.*;

public class FileTest {
        public static void main(String[] args){
            findFile("E:\\dubbo");
        }
        public static void findFile(String path){
            //获得目录下的文件列表
            File[] fileList = new File(path).listFiles();
            //目录下不为空
            if(fileList.length > 0){
                //遍历文件数组,如果是目录,递归调用本方法,如果是文件,判断是不是.java结尾,然后调用读文件方法判断
                for(File file : fileList){
                    if(file.isDirectory()){
                        findFile(file.getAbsolutePath());
                    }else{
                        if(file.getName().endsWith(".java")){
                            threadTest thread = new threadTest(file,"log");
                            new Thread(thread).start();
                        }
                    }
                }
            }
        }
}
 class threadTest implements Runnable{
    private File file;
    private String key;
    public  threadTest(File file,String key) {
        this.file = file;
        this.key = key;
    }
    @Override
    public void run() {
        BufferedReader bufferedReader;
        try {
            //获取文件的读取流
            bufferedReader = new BufferedReader(new FileReader(file));
            StringBuffer sb = new StringBuffer();
            String line = "";
            //读取文件并追加到StringBuffer上
            while((line = bufferedReader.readLine()) != null){
                sb.append(line);
            }
            //匹配是否存在特定的关键字
            if(sb.toString().contains(key)){
                System.out.println(file.getName());
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
}