java实现关键字占位符

转自：https://www.jb51.net/article/198116.htm

python中的关键字占位符非常好用，但java并没有提供，发现网上有人写了一个，还挺好用

public class StringFormatUtil {
    private static final Pattern pattern = Pattern.compile("\{(.*?)\}");
    private static Matcher matcher;

    public static String stringFormat(String sourStr, Map<String, Object> param) {
        String targetStr = sourStr;
        if (param == null)
            return targetStr;
        try {
            matcher = pattern.matcher(targetStr);
            while (matcher.find()) {
                String key = matcher.group();
                String keyclone = key.substring(1, key.length() - 1).trim();
                Object value = param.get(keyclone);
                if (value != null)
                    targetStr = targetStr.replace(key, value.toString());
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        return targetStr;
    }

    public static String stringFormat(String sourStr, Object obj) {
        String targetStr = sourStr;
        matcher = pattern.matcher(targetStr);
        if (obj == null)
            return targetStr;

        PropertyDescriptor pd;
        Method getMethod;
        // 匹配{}中间的内容 包括括号
        while (matcher.find()) {
            String key = matcher.group();
            String keyClone = key.substring(1, key.length() - 1).trim();
            try {
                pd = new PropertyDescriptor(keyClone, obj.getClass());
                getMethod = pd.getReadMethod();// 获得get方法
                Object value = getMethod.invoke(obj);
                if (value != null)
                    targetStr = targetStr.replace(key, value.toString());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return targetStr;
    }

    public static void main(String[] args) {
        String template="select {column} from {table} " +
                "where tenant_code='{tenant_code}' " +
                "and bizmonth='{month}' " +
                "and bizyear='{month}'";
        Map<String, Object> map = new HashMap<>();
        map.put("column","a,b,c");
        map.put("table","tableName");
        map.put("tenant_code","0385");
        map.put("month","2021-09");
        String s = stringFormat(template, map);
        System.out.println(s);
    }
}