Question

String str = "POLYGON((39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824))";

我试图只获得39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824

与

final String coordsOnly = str.replaceAll("\\D\\(\\(\\w\\)\\)", "$2");

但我得到coordsOnly = "POLYGON((39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824))"

我错过了什么？

Answer 1

这里的一个合理方法是匹配以下模式，然后用第一个捕获组替换all：

POLYGON\(\((.*?)\)\)

示例代码：

final String coordsOnly = str.replaceAll("POLYGON\\(\\((.*?)\\)\\)", "$1");

Demo

修改

如果您还需要隔离数字对，则可以在逗号上使用String#split()。实际上，这看起来像数据库查询的输出，我怀疑数据库可能提供更好的方法来获取单个值。但是，如果您无法获得所需的确切输出，此处给出的答案是您的选择。

Answer 2

也许这就是你想要的？：

String rex = "[+-]?([0-9]*[.])?[0-9]+";
Pattern p = Pattern.compile(rex);
String input = "POLYGON((39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824))";
Matcher matcher = p.matcher(input);

while(matcher.find()) {
    System.out.println(matcher.group());
}

Answer 3

实际上，很多。

"\\D" // Matches a non-digit character, but it only matches one,
      // while you need to match a word "POLYGON";
"\\(\\(" // Good. Matches the double left parentheses ((
"\\w"    // One word character? Same issue, you need to match multiple chars. And what about '.'?
"\\)\\)" // Good. Matches the double right parentheses ))

并且转义()不会创建匹配的组;并且\\w只匹配一个字符[a-zA-Z_0-9]，它甚至不匹配.。

我相信你应该尝试这样的事情：

String coords = str.replaceAll("POLYGON\\(\\(([^)]+)\\)\\)", "$1");

Answer 4

试试这个版本：

str = str.replaceAll("[^\\d\\.\\s,]", "");

Answer 5

//Create object for numbering name attributes of lift and cardio rows
var nameNumberManager = {

    reNameNumberAll: function(){
        alert(1);
        var liftRows = this.getLiftRows();
        alert(2);
        this.reNameNumberLiftRows(liftRows);
        alert(3);
        var cardioRows = this.getCardioRows();
        alert(4);
        this.reNameNumberCardioRows(cardioRows);
        alert(5);
        // get all cardio rows
    },
    getLiftRows: function(){
        var liftRows = document.getElementById('liftrows');
        return liftRows;
    },
    getCardioRows: function(){
        var cardioRows = document.getElementById('cardiorows');
        return cardioRows;
    },
    reNameNumberLiftRows: function(liftRows){
        for(var i=0; i<liftRows.length; i++){
            var liftField = liftRows.getElementsByClassName('input').getElementsByClassName('lift')[0];
            var setField = liftRows.getElementsByClassName('setfield');
            var repFields = liftRows.getElementsByClassName('repfield');
            var weightFields = liftRows.getElementsByClassName('weightfield');

            liftField.name = 'lift_string'+i;
            setField.name = 'sets'+i;
            for(var j=0; i<repFields.length; j++){
                repFields[i].name = 'reps'+i;
            }
            for(var j=0; i<weightFields.length; j++){
                weightFields[i].name = 'weight'+i;
            }

        }
    },
    reNameNumberCardioRows: function(cardioRows){
        for(var i=0; i<cardioRows.length; i++){
            var activityField = cardioRows.getElementsByClassName('dropdowntext');
            var minField = cardioRows.getElementsByClassName('minfield');
            var distField = cardioRows.getElementsByClassName('distfield');

            activityField.name = 'cardio_string'+i;
            minField.name = 'minutes'+i;
            distField.name = 'distance'+i;
        }
    },
}

输出：

39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824

Answer 6

另一种选择是替换所有非数字，空格，点或逗号：

str.replaceAll("[\\D&&\\S&&[^,\\.]]", "")

输出：

39.4189453125 37.418708616699824,42.0556640625 37.418708616699824,43.4619140625 34.79181436843146,38.84765625 33.84817790215085,39.4189453125 37.418708616699824

java从字符串中提取数字

6 个答案:

Demo