java封装工具

1.动态遍历Map参数组装get请求参数

 public static String buildQueryString(Map params) {
        StringBuilder queryString = new StringBuilder();
        for (Map.Entry entry : params.entrySet()) {
            String key = entry.getKey();
            String value = Convert.toStr(entry.getValue());
            if (queryString.length() > 0) {
                queryString.append("&");
            }
            try {
                queryString.append(URLEncoder.encode(key, String.valueOf(StandardCharsets.UTF_8)));
                queryString.append("=");
                queryString.append(URLEncoder.encode(value, String.valueOf(StandardCharsets.UTF_8)));
            } catch (UnsupportedEncodingException e) {
                throw new RuntimeException(e);
            }
        }
        return queryString.toString();
    }

 使用

 String url = "http://baidu.com";
        String queryString = buildQueryString(params);  // 构建查询字符串
        String fullUrl = url + "?" + queryString;