Question

如何使用java来计算此xml片段中PolylinePoint元素的数量（对您来说很重要的是，此xml不是文件而是字符串）：

    <LocationInformationRequest>
            <InitialInput>
                <GeoRestriction>
                    <Area>
                        <PolylinePoint>
                            <Longitude>88.1</Longitude>
                            <Latitude>88.2</Latitude>
                            <Altitude>88.3</Altitude>
                        </PolylinePoint>
                        <PolylinePoint>
                            <Longitude>88.4</Longitude>
                            <Latitude>88.5</Latitude>
                            <Altitude>88.6</Altitude>
                        </PolylinePoint>
                        <PolylinePoint>
                            <Longitude>88.7</Longitude>
                            <Latitude>88.8</Latitude>
                            <Altitude>88.9</Altitude>
                        </PolylinePoint>
                    </Area>
                </GeoRestriction>
            </InitialInput>
        </LocationInformationRequest>

使用xml作为文件很容易解决这个问题。但是使用字符串会更困难。有什么想法吗？

感谢您的帮助！

Answer 1

我想你想把你的字符串解析为XML？在这里解释： In Java, how do I parse XML as a String instead of a file?
另一个解决方案，但真的丑陋：如果你对你的XML结构100％肯定（并且确定它不会发生变化），那你可以算一下＆＃34; <PolylinePoint＆＃34;

Answer 2

您可以使用正则表达式：

        String str="<PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint><PolylinePoint><Longitude>88.7</Longitude><Latitude>88.8</Latitude><Altitude>88.9</Altitude></PolylinePoint>";
        Pattern p = Pattern.compile("<PolylinePoint>");
        Matcher m=p.matcher(str);
        int res=0;
        while (m.find()) {
            res++;
        }
        System.out.println(res++);

Answer 3

如何创建Document drom String？

Document document = builder.parse（new InputSource（new StringReader（xmlString）））;

然后你可以轻松使用xPath。

计算XML元素，将其另存为String

3 个答案: