Question

我编写了以下方法，以便在网站上返回所有元素的对象。

public ArrayList<Person> getWantedFields() {
    log.info("retrieve wanted fields");

    resultList = new ArrayList<Person>();

    List<WebElement> fullNames   = driver.findElements(By.xpath("//div[@id='content_head_folge']/h1"));
    List<WebElement> professions = driver.findElements(By.xpath("//div[@id='content_head_folge']/p"));
    List<WebElement> streets     = driver.findElements(By.xpath("//div[@id='content_head_folge']/p/br[1]"));

    //2811 results
    for (int i = 0; i < 2810; i++) {
        resultList.add(new Person(fullNames.get(i).getText(), professions.get(i).getText(), streets.get(i).getText(), null, null, null, null, null));  //here I get the OutOfBounds exception                   
    }
    log.info(resultList.toString());

    return resultList;
}

我猜2811显示的结果太多了。有没有办法迭代网站上的所有字段，而不知道它的大小？

感谢您的回复！

更新

使用

public ArrayList<Person> getWantedFields() {
    log.info("retrieve wanted fields");

    resultList = new ArrayList<Person>();

    List<WebElement> fullNames   = driver.findElements(By.xpath("//div[@id='content_head_folge']/h1"));
    List<WebElement> professions = driver.findElements(By.xpath("//div[@id='content_head_folge']/p"));
    List<WebElement> streets     = driver.findElements(By.xpath("//div[@id='content_head_folge']/p/br[1]"));

    //2811 results
    for (int i = 0; i < fullNames.size(); i++) {
        resultList.add(new Person(fullNames.get(i).getText(), professions.get(i).getText(), streets.get(i).getText(), null, null, null, null, null));  //here I get the OutOfBounds exception                   
    }
    log.info(resultList.toString());

    return resultList;
}

我明白了：

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
    at java.util.ArrayList.rangeCheck(ArrayList.java:635)
    at java.util.ArrayList.get(ArrayList.java:411)
    at com.Test.service.PM.getFields(PM.java:152)
    at com.Scraponator.gui.PersonLookup.main(PersonLookup.java:36)

Answer 1

您可以使用列表的size()：

for (int i = 0; i < fullNames.size(); i++) {
    resultList.add(new Person(fullNames.get(i).getText(), professions.get(i).getText(), streets.get(i).getText(), null, null, null, null, null));  //here I get the nullpointer exception                   
}

Answer 2

你在这里走在薄冰上。你怎么能确定所有三个列表都有相同的大小？如果有间隙（缺少子元素）怎么办？

List<WebElement> fullNames   = driver.findElements(By.xpath("//div[@id='content_head_folge']/h1"));
List<WebElement> professions = driver.findElements(By.xpath("//div[@id='content_head_folge']/p"));
List<WebElement> streets     = driver.findElements(By.xpath("//div[@id='content_head_folge']/p/br[1]"));

if( fullNames.size() != professions.size() || fullNames.size() != streets.size() ){
    throw new IllegalStateException( "can't get the data" );
}

IndexOutOfBoundException - 从站点检索所有元素

2 个答案: