java正则表达式匹配文本中想要的字符串

需求:获取一个本地文件中所有符合 $[MAKE_PACKAGE] 格式的字符串,并输出到另一个文件中.

public static void main(String[] args) throws Exception {
        
        loadVar("src/cn/don9/templates/Action.txt","src/cn/don9/templateVar/SysActionVar.txt");
        
    }
    
    public static void loadVar(String infilePath,String outfilePath) throws Exception{
        //定义set集合,实现去重效果
        Set<String> result = new HashSet<String>();
        //定义正则表达式
        String regex = "[\$][\[]\w+[\]]";
        Pattern pattern = Pattern.compile(regex);
        
        //读取文件
        File file = new File(infilePath);
        BufferedReader br = new BufferedReader(new FileReader(file));
        String line;
        while((line=br.readLine())!=null){
            //匹配文本中每行的字符串
            Matcher matcher = pattern.matcher(line);
            //发现匹配的字符串,存入set中
            while(matcher.find()){
                result.add(matcher.group());
            }
        }
        
        //加载输出文件
        File outfile = new File(outfilePath);
        BufferedWriter bw = new BufferedWriter(new FileWriter(outfile));
        for(String var:result){
            //写入字符串
            bw.write(var+"
");
        }
        
        br.close();
        bw.close();
        
        System.out.println("读取完毕!");
    }

运行结果: