/*** 
     * @Author zhaohp
     * @Date 2018/9/29 16:07
     * @Param [jsonString, set]
     * @Return void
     * @Description: 通过正则表达式来匹配电话号码
     */
    public void getPhoneStr(String jsonString, Set<String> set) {
        String regex = "\"phone\":\"(.*?)\\\"";//使用非贪婪模式
        Matcher matcher = Pattern.compile(regex).matcher(jsonString);
        while (matcher.find()) {
            set.add(matcher.group(1));
        }
    }

    public static void main(String[] args) {

        String jsonString = "{\"page_size\":\"12321321\",\"page_size\":\"123\",\"page_index\":0,\"page_count\":0,\"has_next\":false,\"datas\":null,\"code\":0,\"issuccess\":true,\"msg\":null}";
        String regex = "\"page_size\":\"(.*?)\\\"";//使用非贪婪模式
        Matcher matcher = Pattern.compile(regex).matcher(jsonString);
        while (matcher.find()) {
            String ret = matcher.group(1);
            System.out.println("key:" + matcher.group(1));
        }

        String str = "{\"keyword\":\"xin \"hua\",\"type\":\"news\",\"countryName\":\"not中国\"," +
                "\"pageNo\":1,\"pageSize\":10,\"beginDate\":\"\"\"2018-05-01 00:00:00\"\"\"," +
                "\"endDate\":\"2018-05-09 23:59:59\"}";
        Pattern pattern = Pattern.compile("\"([a-zA-z0-9]{0,})\":\"{1}([a-zA-z0-9\\-\\s\\:\\u4e00-\\u9fa5\"]{0,})\"{1}[\\,\\}]{1}|" +
                "\"([a-zA-z0-9]{0,})\":([a-zA-z0-9\\-\\s\\:\\u4e00-\\u9fa5\"]{0,})[\\,\\}]{1}");
        Matcher matcher1 = pattern.matcher(str);
        while (matcher1.find()){
            if(matcher1.group(1)!=null) {
                //System.out.println("key:" + matcher1.group(1));
                System.out.println("value:" + matcher1.group(2));
            }else{
                // System.out.println("key:" + matcher1.group(3));
                System.out.println("value:" + matcher1.group(4));
            }
        }
    }

返回结果

key:12321321
key:123
value:xin “hua
value:news
value:not中国
value:1
value:10
value:”“2018-05-01 00:00:00"”
value:2018-05-09 23:59:59