How do I preserve line breaks when using jsoup to convert html to plain text?

我有以下密码:

 public class NewClass {
public String noTags(String str){
return Jsoup.parse(str).text();
}




public static void main(String args[]) {
String strings="<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN \">" +
"<HTML> <HEAD> <TITLE></TITLE> <style>body{ font-size: 12px;font-family: verdana, arial, helvetica, sans-serif;}</style> </HEAD> <BODY><p><b>hello world</b></p><p><br><b>yo</b> <a href=\"http://google.com\">googlez</a></p></BODY> </HTML> ";


NewClass text = new NewClass();
System.out.println((text.noTags(strings)));
}

结果是:

hello world yo googlez

但是我想打破这个界限:

hello world
yo googlez

我看过 Jsoup 的 TextNode # getWhole Text ()，但我不知道如何使用它。

如果我解析的标记中有一个 <br>，那么我如何在结果输出中得到一个换行符呢？

70490 次浏览
小开

试试这个:

public String noTags(String str){
Document d = Jsoup.parse(str);
TextNode tn = new TextNode(d.body().html(), "");
return tn.getWholeText();
}
小开

和

Jsoup.parse("A\nB").text();

你有输出

"A B"

而不是

A


B

为此，我使用:

descrizione = Jsoup.parse(html.replaceAll("(?i)<br[^>]*>", "br2n")).text();
text = descrizione.replaceAll("br2n", "\n");
小开 
Jsoup.clean(unsafeString, "", Whitelist.none(), new OutputSettings().prettyPrint(false));

We're using this method here:

public static String clean(String bodyHtml,
String baseUri,
Whitelist whitelist,
Document.OutputSettings outputSettings)

通过传递它 Whitelist.none()，我们可以确保删除所有的 HTML。

通过传递 new OutputSettings().prettyPrint(false)，我们确保输出不会被重新格式化，并且保留了换行符。

小开

试试这个:

public static String cleanPreserveLineBreaks(String bodyHtml) {


// get pretty printed html with preserved br and p tags
String prettyPrintedBodyFragment = Jsoup.clean(bodyHtml, "", Whitelist.none().addTags("br", "p"), new OutputSettings().prettyPrint(true));
// get plain text with preserved line breaks by disabled prettyPrint
return Jsoup.clean(prettyPrintedBodyFragment, "", Whitelist.none(), new OutputSettings().prettyPrint(false));
}
小开

可以遍历给定的元素

public String convertNodeToText(Element element)
{
final StringBuilder buffer = new StringBuilder();


new NodeTraversor(new NodeVisitor() {
boolean isNewline = true;


@Override
public void head(Node node, int depth) {
if (node instanceof TextNode) {
TextNode textNode = (TextNode) node;
String text = textNode.text().replace('\u00A0', ' ').trim();
if(!text.isEmpty())
{
buffer.append(text);
isNewline = false;
}
} else if (node instanceof Element) {
Element element = (Element) node;
if (!isNewline)
{
if((element.isBlock() || element.tagName().equals("br")))
{
buffer.append("\n");
isNewline = true;
}
}
}
}


@Override
public void tail(Node node, int depth) {
}
}).traverse(element);


return buffer.toString();
}

还有你的密码

String result = convertNodeToText(JSoup.parse(html))
小开

使用 textNodes()获取文本节点的列表。然后将它们与 \n连接起来作为分隔符。 下面是我使用的一些 Scala 代码，java 端口应该很简单:

val rawTxt = doc.body().getElementsByTag("div").first.textNodes()
.asScala.mkString("<br />\n")
小开

保留换行符的真正解决方案应该是这样的:

public static String br2nl(String html) {
if(html==null)
return html;
Document document = Jsoup.parse(html);
document.outputSettings(new Document.OutputSettings().prettyPrint(false));//makes html() preserve linebreaks and spacing
document.select("br").append("\\n");
document.select("p").prepend("\\n\\n");
String s = document.html().replaceAll("\\\\n", "\n");
return Jsoup.clean(s, "", Whitelist.none(), new Document.OutputSettings().prettyPrint(false));
}

它符合以下要求:

  1. 如果原始的 html 包含换行符(n) ，它将被保留
  2. 如果原始 html 包含 br 或 p 标记，它们将被转换为 newline (n)。
小开 
/**
* Recursive method to replace html br with java \n. The recursive method ensures that the linebreaker can never end up pre-existing in the text being replaced.
* @param html
* @param linebreakerString
* @return the html as String with proper java newlines instead of br
*/
public static String replaceBrWithNewLine(String html, String linebreakerString){
String result = "";
if(html.contains(linebreakerString)){
result = replaceBrWithNewLine(html, linebreakerString+"1");
} else {
result = Jsoup.parse(html.replaceAll("(?i)<br[^>]*>", linebreakerString)).text(); // replace and html line breaks with java linebreak.
result = result.replaceAll(linebreakerString, "\n");
}
return result;
}

通过调用有问题的 html，包含 br，以及您希望用作临时换行占位符的任何字符串来使用。 例如:

replaceBrWithNewLine(element.html(), "br2n")

递归将确保您用作 newline/linebreak 占位符的字符串实际上永远不会出现在源 html 中，因为它将一直添加“1”，直到在 html 中找不到 linkbreak 占位符字符串为止。它不会遇到 Jsoup.clean 方法似乎遇到的特殊字符的格式问题。

小开 
text = Jsoup.parse(html.replaceAll("(?i)<br[^>]*>", "br2n")).text();
text = descrizione.replaceAll("br2n", "\n");

works if the html itself doesn't contain "br2n"

那么,

text = Jsoup.parse(html.replaceAll("(?i)<br[^>]*>", "<pre>\n</pre>")).text();

工作更可靠，更容易。

小开

根据用户121196和绿色贝雷帽的 select和 <pre>的答案，对我来说唯一有效的解决方案是:

org.jsoup.nodes.Element elementWithHtml = ....
elementWithHtml.select("br").append("<pre>\n</pre>");
elementWithHtml.select("p").prepend("<pre>\n\n</pre>");
elementWithHtml.text();
小开

这是我将 html 翻译成文本的版本(实际上是 user121196的修改版本)。

这不仅保留了换行符，而且还格式化了文本，删除了过多的换行符和 HTML 转义符号，这样您将从 HTML 中获得更好的结果(在我的例子中是从邮件中收到的)。

它最初是用 Scala 编写的，但是您可以很容易地将它更改为 Java

def html2text( rawHtml : String ) : String = {


val htmlDoc = Jsoup.parseBodyFragment( rawHtml, "/" )
htmlDoc.select("br").append("\\nl")
htmlDoc.select("div").prepend("\\nl").append("\\nl")
htmlDoc.select("p").prepend("\\nl\\nl").append("\\nl\\nl")


org.jsoup.parser.Parser.unescapeEntities(
Jsoup.clean(
htmlDoc.html(),
"",
Whitelist.none(),
new org.jsoup.nodes.Document.OutputSettings().prettyPrint(true)
),false
).
replaceAll("\\\\nl", "\n").
replaceAll("\r","").
replaceAll("\n\\s+\n","\n").
replaceAll("\n\n+","\n\n").
trim()
}
小开

基于对这个问题的其他回答和评论，似乎大多数来这里的人真的是在寻找一个通用的解决方案，它将提供一个格式良好的 HTML 文档的纯文本表示。我知道我是。

Fortunately JSoup already provide a pretty comprehensive example of how to achieve this: Java

示例 FormattingVisitor可以很容易地根据您的偏好进行调整，并处理大多数块元素和行包装。

为了避免链接腐败，以下是 Jonathan Hedley的完整解决方案:

package org.jsoup.examples;


import org.jsoup.Jsoup;
import org.jsoup.helper.StringUtil;
import org.jsoup.helper.Validate;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.nodes.Node;
import org.jsoup.nodes.TextNode;
import org.jsoup.select.Elements;
import org.jsoup.select.NodeTraversor;
import org.jsoup.select.NodeVisitor;


import java.io.IOException;


/**
* HTML to plain-text. This example program demonstrates the use of jsoup to convert HTML input to lightly-formatted
* plain-text. That is divergent from the general goal of jsoup's .text() methods, which is to get clean data from a
* scrape.
* <p>
* Note that this is a fairly simplistic formatter -- for real world use you'll want to embrace and extend.
* </p>
* <p>
* To invoke from the command line, assuming you've downloaded the jsoup jar to your current directory:</p>
* <p><code>java -cp jsoup.jar org.jsoup.examples.HtmlToPlainText url [selector]</code></p>
* where <i>url</i> is the URL to fetch, and <i>selector</i> is an optional CSS selector.
*
* @author Jonathan Hedley, jonathan@hedley.net
*/
public class HtmlToPlainText {
private static final String userAgent = "Mozilla/5.0 (jsoup)";
private static final int timeout = 5 * 1000;


public static void main(String... args) throws IOException {
Validate.isTrue(args.length == 1 || args.length == 2, "usage: java -cp jsoup.jar org.jsoup.examples.HtmlToPlainText url [selector]");
final String url = args[0];
final String selector = args.length == 2 ? args[1] : null;


// fetch the specified URL and parse to a HTML DOM
Document doc = Jsoup.connect(url).userAgent(userAgent).timeout(timeout).get();


HtmlToPlainText formatter = new HtmlToPlainText();


if (selector != null) {
Elements elements = doc.select(selector); // get each element that matches the CSS selector
for (Element element : elements) {
String plainText = formatter.getPlainText(element); // format that element to plain text
System.out.println(plainText);
}
} else { // format the whole doc
String plainText = formatter.getPlainText(doc);
System.out.println(plainText);
}
}


/**
* Format an Element to plain-text
* @param element the root element to format
* @return formatted text
*/
public String getPlainText(Element element) {
FormattingVisitor formatter = new FormattingVisitor();
NodeTraversor traversor = new NodeTraversor(formatter);
traversor.traverse(element); // walk the DOM, and call .head() and .tail() for each node


return formatter.toString();
}


// the formatting rules, implemented in a breadth-first DOM traverse
private class FormattingVisitor implements NodeVisitor {
private static final int maxWidth = 80;
private int width = 0;
private StringBuilder accum = new StringBuilder(); // holds the accumulated text


// hit when the node is first seen
public void head(Node node, int depth) {
String name = node.nodeName();
if (node instanceof TextNode)
append(((TextNode) node).text()); // TextNodes carry all user-readable text in the DOM.
else if (name.equals("li"))
append("\n * ");
else if (name.equals("dt"))
append("  ");
else if (StringUtil.in(name, "p", "h1", "h2", "h3", "h4", "h5", "tr"))
append("\n");
}


// hit when all of the node's children (if any) have been visited
public void tail(Node node, int depth) {
String name = node.nodeName();
if (StringUtil.in(name, "br", "dd", "dt", "p", "h1", "h2", "h3", "h4", "h5"))
append("\n");
else if (name.equals("a"))
append(String.format(" <%s>", node.absUrl("href")));
}


// appends text to the string builder with a simple word wrap method
private void append(String text) {
if (text.startsWith("\n"))
width = 0; // reset counter if starts with a newline. only from formats above, not in natural text
if (text.equals(" ") &&
(accum.length() == 0 || StringUtil.in(accum.substring(accum.length() - 1), " ", "\n")))
return; // don't accumulate long runs of empty spaces


if (text.length() + width > maxWidth) { // won't fit, needs to wrap
String words[] = text.split("\\s+");
for (int i = 0; i < words.length; i++) {
String word = words[i];
boolean last = i == words.length - 1;
if (!last) // insert a space if not the last word
word = word + " ";
if (word.length() + width > maxWidth) { // wrap and reset counter
accum.append("\n").append(word);
width = word.length();
} else {
accum.append(word);
width += word.length();
}
}
} else { // fits as is, without need to wrap text
accum.append(text);
width += text.length();
}
}


@Override
public String toString() {
return accum.toString();
}
}
}
小开

试试这个:

    doc.outputSettings(new OutputSettings().prettyPrint(false));


//select all <br> tags and append \n after that
doc.select("br").after("\\n");


//select all <p> tags and prepend \n before that
doc.select("p").before("\\n");


//get the HTML from the document, and retaining original new lines
String str = doc.html().replaceAll("\\\\n", "\n");
小开

对于更复杂的 HTML 来说，上面的解决方案都不能很好地工作; 我能够成功地进行转换，同时保留换行符:

Document document = Jsoup.parse(myHtml);
String text = new HtmlToPlainText().getPlainText(document);

(第1.10.3版)

小开

在 Jsoupv1.11.2上，我们现在可以使用 Element.wholeText()。

String cleanString = Jsoup.parse(htmlString).wholeText();

user121196's 回答仍然工作。但是 wholeText()保留了文本的对齐方式。


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