简单的方法:

public static String escapeHTML(String s) {
    StringBuilder out = new StringBuilder(Math.max(16, s.length()));
    for (int i = 0; i < s.length(); i++) {
        char c = s.charAt(i);
        if (c > 127 || c == '"' || c == '\'' || c == '<' || c == '>' || c == '&') {
            out.append("&#");
            out.append((int) c);
            out.append(';');
        } else {
            out.append(c);
        }
    }
    return out.toString();
}

基于https://stackoverflow.com/a/8838023/1199155(放大器不在那里)。根据http://www.w3.org/TR/html4/sgml/entities.html的说法，if子句中选中的四个字符是唯一低于128的字符

StringEscapeUtils from Apache Commons Lang:

import static org.apache.commons.lang.StringEscapeUtils.escapeHtml;
// ...
String source = "The less than sign (<) and ampersand (&) must be escaped before using them in HTML";
String escaped = escapeHtml(source);

版本3:

import static org.apache.commons.lang3.StringEscapeUtils.escapeHtml4;
// ...
String escaped = escapeHtml4(source);

Apache Commons的替代方案:使用Spring的htmltils。htmlEscape(字符串输入)方法。

对于使用谷歌番石榴的人:

import com.google.common.html.HtmlEscapers;
[...]
String source = "The less than sign (<) and ampersand (&) must be escaped before using them in HTML";
String escaped = HtmlEscapers.htmlEscaper().escape(source);

Be careful with this. There are a number of different 'contexts' within an HTML document: Inside an element, quoted attribute value, unquoted attribute value, URL attribute, javascript, CSS, etc... You'll need to use a different encoding method for each of these to prevent Cross-Site Scripting (XSS). Check the OWASP XSS Prevention Cheat Sheet for details on each of these contexts. You can find escaping methods for each of these contexts in the OWASP ESAPI library -- https://github.com/ESAPI/esapi-java-legacy.

虽然@dfa答案的org.apache.commons.lang.StringEscapeUtils.escapeHtml是很好的，我过去使用过它，它不应该用于转义HTML(或XML)属性，否则空白将被规范化(意味着所有相邻的空白字符成为一个单独的空格)。

我知道这一点，因为我的库(JATL)中有一些没有保留空白的属性的bug。因此，我有一个drop in (copy n’paste)类(其中一些是从JDOM中偷来的)来区分属性和元素内容的转义。

虽然这在过去可能没有那么重要(适当的属性转义)，但考虑到HTML5的数据属性使用，它变得越来越有趣。