这个问题有两个答案:

In you want to stick to pure Java, with Java 14 being released in March 2020, you can leverage the JEP 368 - Text Blocks, in Second Preview mode. Actually the feature is in preview mode in other releases (at least 13 has it). I created and example set here. While this feature is useful, it can be easily abused. Remember that Java requires compilation - having large character arrays in your code can be an easy way to shoot yourself in the leg (if you want a quick change, you will need recompilation - that toolset might not be available to the guy operating your application).

根据我的经验，建议在配置文件中保留大字符串(通常是应用程序操作员可以/应该在运行时更改的字符串)。

总结:负责地使用文本块:)。

由于Java(还)不支持多行字符串，目前唯一的方法是使用前面提到的技术之一来破解它。我使用上面提到的一些技巧构建了下面的Python脚本:

import sys
import string
import os

print 'new String('
for line in sys.stdin:
    one = string.replace(line, '"', '\\"').rstrip(os.linesep)
    print '  + "' + one + ' "'
print ')'

把它放在一个名为javastringify.py的文件中，把你的字符串放在一个名为mystring.txt的文件中，然后像下面这样运行:

cat mystring.txt | python javastringify.py

然后，您可以复制输出并将其粘贴到编辑器中。

修改这需要处理任何特殊情况，但这是为我的需要。希望这能有所帮助!

从问题中还不完全清楚作者是否有兴趣处理某种需要有一些动态值的格式化大字符串，但如果是这种情况，像StringTemplate (http://www.stringtemplate.org/)这样的模板引擎可能非常有用。

下面是一个使用StringTemplate的简单代码示例。实际的模板("Hello， < name >")可以从外部纯文本文件加载。模板中的所有缩进都将被保留，不需要转义。

import org.stringtemplate.v4.*;
 
public class Hello {
    public static void main(String[] args) {
        ST hello = new ST("Hello, <name>");
        hello.add("name", "World");
        System.out.println(hello.render());
    }
}

附注:为了可读性和本地化目的，从源代码中删除大块文本总是一个好主意。

我所知道的唯一方法是用加号连接多行

    import org.apache.commons.lang3.StringUtils;

    String multiline = StringUtils.join(new String[] {
        "It was the best of times, it was the worst of times ", 
        "it was the age of wisdom, it was the age of foolishness",
        "it was the epoch of belief, it was the epoch of incredulity",
        "it was the season of Light, it was the season of Darkness",
        "it was the spring of hope, it was the winter of despair",
        "we had everything before us, we had nothing before us",
        }, "\n");

String newline = System.getProperty ("line.separator");
string1 + newline + string2 + newline + string3

但是，最好的替代方法是使用String.format

String multilineString = String.format("%s\n%s\n%s\n",line1,line2,line3);